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Dissertations / Theses on the topic 'Root crops'
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Boyd, Philip Anthony. "Root crops in the diets of growing pigs." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292619.
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Milan, Abd Rahman. "Genetic manipulation of storage root development in horticultural crops." Thesis, De Montfort University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246516.
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Cheema, M. U. A. "Dormancy and sprout control in root and tuber crops." Thesis, University of Greenwich, 2010. http://gala.gre.ac.uk/6890/.
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Research objectives were to study dormancy/sprout control in potato and sweetpotato, and to identify novel sprout control strategies. Consistent with sprout stimulation by gibberellins (GAs) in potato, 10 mM GA3 enhanced sprout length and number in sweetpotato roots and sprout growth was decreased by 20 ml/L piccolo (GA synthesis inhibitor). Continuous application of 10 ppm ethylene or greater prevented sprouting in sweetpotato roots over 4 weeks storage at 25° C. Sprout growth was also inhibited by 1000 ppm aminoethoxyvinylglycine (AVG) (ethylene synthesis inhibitor) or 625 ppb 1-methylcyclopropene (1-MCP) (ethylene antagonist). Continuous ethylene treatment or single 1-MCP treatment could be a practical sprout control method for sweetpotatoes stored at >15° C. 5 ppm or greater ethylene increased root respiration rates, but this effect was reduced by 1-MCP or AVG. Sugar content in ethylene treated roots +/- 1-MCP or AVG were lower than untreated roots, with lowest levels in roots treated with ethylene alone. Hormonal control of dormancy/sprout growth was studied in excised buds from potato tubers transformed to over-express a bacteria gene encoding 1-deoxy-D-xylulose 5 phosphate synthase (DXS), which exhibit arrested buds, Five weeks post-harvest over-expressing lines, DXS1 and DXS2, showed greater sprout growth compared to wild type when treated with 1 mM GA3 or tZR in 2009, whereas DXS1 showed less sprout growth 4 weeks post-harvest in 2007. There was no difference in DXS1 and DXS2 behaviour 4 months after harvest in 2007. The different behaviour of DXS1 over seasons and with time from harvest underlines how tuber state can change with maturity. No consistent differences were found in chemical profile of peel among potato tubers of accessions with a range of dormancy characteristics. Although 1, 4-Dimethylnaphthalene has been identified as a natural sprout suppressant, it could not be detected in any accession even though measurements were sensitive to below 100 ppb.
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Baimey, Hugues Kossi. "Scutellonema bradys as a pathogen of yam in Benin." Thesis, Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-10252006-164955.
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Naab, Jesse Bonaventure. "Interaction of canopy and root system in water use of potato." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308564.
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McGinley, Susan. "Aeroponic Herbs: A Cultivation System For Clean, Consistent Root Crops." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/622256.
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Delft, Gert-Jan van. "Root architecture in relation to avoidance of Striga hermonthica infection." Thesis, University of York, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297312.
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Halchak, Jennifer L. "Root growth dynamics and cultivation aspects of Kosteletzkya virginica (Malvaceae)." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 132 p, 2009. http://proquest.umi.com/pqdweb?did=1889098991&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Taylor, Sharyn Patricia. "The root lesion nematode, Pratylenchus neglectus, in field crops in South Australia." Title page, contents and summary only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09pht2462.pdf.
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Includes bibliographical references (leaves 241-25). Aims to evaluate sampling procedures; assess the extent and magnitude of yield loss caused by Pratylenchus neglectus; assess the population dynamics of Pratylenchus neglectus in cereals; determine whether resistance occurs in field crops; and, assess whether variation occurs between geographically isolated species of Pratylenchus neglectus
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Manderioli, Lisa Marie. "NON-STARCH POLYSACCHARIDES IN THE ROOTS OF CUCURBITA FOETIDISSIMA (BUFFALO GOURD, FIBER ANALYSIS, HEMICELLULOSE)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275456.
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Asmah, Augustus E. "Vesicular-arbuscular mycorrhizal fungal infection in some tropical crops in relation to soil management practices." Thesis, University of Aberdeen, 1991. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU033750.
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The dependency of maize (Zea mays L.) and bambara groundnut (Vigna subterranea) grown in acid tropical soils, on the mycorrhizal condition for improved growth and nutrient uptake, and the effects of various management practices on root infection by vesicular-arbuscular mycorrhizal fungi in maize plants were investigated. The effect of soil pH on mycorrhiza formation in perennial ryegrass and maize was also investigated using a temperate soil in which pH levels had been maintained in the field over a long period. Infection of roots of maize and bambara groundnut plants by vesicular-arbuscular mycorrhizal (VAM) fungi indigenous to the tropical soils, resulted in increased plant dry weights as well as increased uptake of nutrients. The population of VAM fungi in the soils consisted of several species in the genera Glomus and Gigaspora. The foliar application of two systemic fungicides (Triforine and calixin) to maize plants resulted in reduced infection with the application of calixin compared to control plants. Root infection by VAM fungi was not different from that of control plants when triforine was applied. Two phosphorus sources (triple superphosphate and Ghafsa phosphate rock) applied to soils at rates equivalent to 22kg ha-1 and 44kg ha-1 had varied effects on VAM fungal infection in maize roots. Phosphate rock applied at both rates and triple superphosphate applied at the lower rate (22kg ha -1) increased root infection compared to that for triple superphosphate at the higher rate. It was suggested that the increased availability of the relatively soluble triple superphosphate was responsible for the reduced infection. The effect of lime application on VAM fungal infection was dependent on the type of phosphorus fertilizer applied to the soils. Increased root infection occurred when lime was applied in addition to triple superphosphate in comparison to phosphate rock. Without lime application, increased infection occurred when phosphate rock was applied compared to triple superphosphate. In the temperate soil with pH maintained over a long period, no VAM fungal infection was found at pH values below 5.0 when ryegrass was the host, although infection occurred when maize was the host plant. There was an effect of host plant on the infectivity of the fungi present in the soils with low pH but infection was low in comparison with that in soil at pH values above 5.0 indicating that management practices which result in soil pH changes may influence mycorrhizal associations in different plant species to different extents. The application of phosphate rock was beneficial to mycorrhiza formation and it was suggested that fertilizer practices which involve the use of phosphate rock could confer additional benefits that can be derived from increased mycorrhiza formation.
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Creel, Sarah Frances. "Effect of acacia gum on bare root nursery crops and in cutting propagation." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Theses/CREEL_SARAH_14.pdf.
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Hall, David Shane. "Soil-plant root relationships of herbaceous biomass crops grown on the Piedmont of Virginia." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08182009-040419/.
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Olsson, Christer H. B. "Diagnosis of root-infecting Phytophthora spp. /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5483-2.pdf.
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Smith, Caroline Louise. "Biological control of root-knot nematodes (Meloidogyne spp.) with Pasteuria penetrans and Verticillium chlamydosporium in Costa Rica." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297317.
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Giese, William Gill Jr. "The Effect of Complete Vineyard Floor Ground Covers and Root Pruning on Cabernet Sauvignon." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/64309.
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Complete vineyard floor cover cropping and root pruning (RP) were evaluated for their ability to regulate excessive vegetative growth and improve berry and wine composition of ‘Cabernet Sauvignon’ (Vitis vinifera L.). Treatments were: tall fescue (Festuca arundinacea Shreb.) ‘KY-31’ and ‘Elite II’, hard fescue (Festuca ovina L.) ‘Aurora Gold’, perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata L.), and an under-trellis herbicide strip combined with KY-31fescue interrows. Compared to herbicide strip/non-root pruned (NRP), Elite II fescue reduced vine pruning weight (kg/vine) 28%, individual cane weight (g) 20%, and canopy leaf layer number 25%. KY-31 fescue/RP lowered vine pruning weights 29% compared to an 8% reduction in pruning weights of vines grown in herbicide strip/NRP plots from 2005 to 2010. KY-31 fescue produced the greatest biomass and stand density. With the exception of a yield reduction in vines grown with KY-31 fescue in 2006, cover crops minimally decreased grape yield. Yearly climatic variation had a greater effect on berry weight and composition (pH, TSS, TA) than did treatments. Limited treatment differences detected in chemical compounds by gas chromatography–mass spectrometry (GC-MS) analysis in wines made from treatment vines in 2010 were correlated to descriptive sensory terms. Cover crop water use, as evapotranspiration, determined by mini-lysimeter (ML), ranged from 3.28 mm/d for KY-31 fescue to 1.52 mm/d for herbicide-treated plots. In 2008, root biomass of vines grown on KY-31 fescue/RP was increased at the 60 to 80 and 80 to 100 cm soil depths compared to root biomass of KY-31 fescue/NRP vines at those depths. Cover crops minimally impacted vine water potential (ΨPD, Ψmd, Ψstem) and grapevine nitrogen levels relative to the herbicide strip, indicating that the grasses were not overly competitive with grapevines. Root pruning and complete vineyard floor cover crops favorably reduced grapevine vegetative growth, although treatment effects diminished over time, possibly in response to redistribution of grapevines’ roots and climatic variation at the site.Ph. D.
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Maplestone, P. E. "Interactions between soil bacteria and the take-all fungus : Root colonisation and potential for biological control." Thesis, University of Bristol, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372019.
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Daniel, John Sathiaseelan. "Strategies for the management of root-knot nematodes with biocontrol agents and crop rotations for vegetable crops in small farms." Thesis, University of Reading, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402591.
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Andersson, Allan. "Nitrogen redistribution in spring wheat : root contribution, spike translocations and protein quality /." Alnarp : Dept. of Crop Science, Swedish Univ. of Agricultural Sciences, 2005. http://epsilon.slu.se/200510.pdf.
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Hatch, Tremain Archer. "Groundcover, rootstock and root restriction effects on vegetative growth, crop yield components, and fruit composition of Cabernet Sauvignon." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/78134.
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Wine vineyards in humid environments like the mid-Atlantic United States are characterized by vines that develop too much vegetative growth for optimum quality wine production. Cover crops, rootstocks and rootzone restriction were evaluated for their effect on vegetative and reproductive growth on Cabernet Sauvignon. Treatments were arranged in a strip-split-split plot arrangement with under-trellis cover crops (UTCC) compared to row-middle only cover crop combined with 1-m weed-free strips in the vine row as main plots. Rootstocks riparia Gloire, 420-A, and 101-14 were sub-plots, while sub-sub-plots comprised two treatments: vines were either planted in root-restrictive (RR), fabric bags (0.016 m3) at vineyard establishment (2006), or were planted without root restriction. All three factors were effective in suppressing vegetative development as measured by rate and extent of shoot growth, lateral shoot development, trunk circumference, and dormant pruning weights. Canopies of vines with UTCC and RR had reduced leaf layer values by approximately 21% and 23% compared to conventional controls. The principal effect of the UTCC and the RR treatments was a sustained reduction in stem (xylem) water potential. UTCC and RR caused significant 7 and 10% reductions in berry weight, compared to their conventional controls. Berry weights of vines grafted to riparia were greater than those of vines grafted to other rootstocks. Wine made from UTCC and RR treatments increased red wine color compared to herbicide UTGC and NRR, respectively. This study identified treatments that improve vine balance while simultaneously improving grape composition and potential wine quality.Master of Science
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Pijl, Isabelle. "Drip fertigation : effects on water movement, soil characteristics and root distribution." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52245.
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Thesis (MScAgric)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: The application of water and nutrients via a drip irrigation system influences the water distribution in the soil, soil characteristics and root distribution beneath the dripper. To determine the water distribution pattern beneath a dripper in sandy soil, EnviroSCAN (Sentek) capacitance probes were installed directly below the dripper and at distances of 20, 40 and 60 cm from the dripper. The continuous monitoring of the soil water content (SWC) beneath the dripper provided a good indication of how the water applied through the dripper is distributed in the soil. In this study a semi-impermeable layer in the soil was detected through observing water accumulation patterns in the SWC. Water accumulated above the layer and SWC values increased to far above the upper level of easily available soil water (EAWupper),while the lower soil layers remained drier. The measurements also show that the horizontal water movement is restricted to 20 cm from the dripper. Specific parameters, such as the lower level of easily available soil water (EAWlower),can be used to determine optimal irrigation management. Together with the water distribution study, the root distribution beneath a dripper was also investigated. A high concentration of roots in the area beneath the dripper was found, which corresponds with the area wetted by irrigation. In another study, three irrigationlfertigation methods where investigated to ascertain the influence on soil characteristics and root distribution. These were: micro irrigation (MI) (micro-spinner irrigation with broadcast granular fertilization), conventional drip fertigation (CDF) (daily drip irrigation with daily or weekly fertigation with a unbalanced nutrient solution, containing macronutrients only) and daily drip fertigation (DDF) (daily fertigation of a balanced nutrient solution, containing macro- and micronutrients). The study was conducted in two locations, viz. in the Western Cape Province, on sandy soil, and in the Eastern Cape Province, on silt loam soil. Micro Irrigation: A wide and even root distribution in the entire wetted volume was found on the sandy and silt loam soil. On the sandy soil, the soil pH(KC1)directly beneath the spinner was significantly lower than the pH(KC1)at positions further away from the spinner. Conventional Drip Fertigation: Root studies on sandy soil indicate a poor root development beneath the dripper, with a high concentration of roots in the area between the drippers. The poor root development directly beneath the dipper may be due to oxygen deficiency and/or acidification beneath the dripper. The soil pH(KC1)values show a significant lower pH(KC1)value directly beneath the dripper than further away. In comparison to the sandy soil, the roots developed well beneath a dripper in a silt loam soil. It appears as if soil acidity and/or oxygen deficiency was not a problem on this soil type. The rest of the root system was also well developed. This may be due to this soil's higher water holding capacity which creates a bigger wetted zone. Daily Drip Fertigation: In the sandy soil it seems that the roots developed in a continuous column beneath the dripper line, with little root development further than 20 cm from the dripper line. Where over-irrigation occurred, it caused a poor root development directly beneath the dripper. The root density in this treatment was much higher than in the other two treatments. The use of a balanced nutrient solution and pulse irrigation may be reasons for the better root development. In a silt loam soil a very high concentration of roots was found beneath the dripper and the rest of the root system was also well developed. As with the CDF treatment, it appears as if oxygen deficiency was not a problem on this soil type.
AFRIKAANSE OPSOMMING: Die toediening van water en voedingstowwe deur 'n drip-besproeiings stelsel beïnvloed die waterverspreiding in die grond sowel as die grondeienskappe en wortelverspreiding onder die dripper. Die waterverspreiding onder 'n dripper in 'n sandgrond is bepaal deur EnviroSCAN kapasitansie meetpenne direk onder die dripper en 20, 40 en 60 cm van 'n dripper af te installeer. Die aaneenlopende monitering van die grondwaterinhoud het 'n goeie indikasie van waterverspreiding in die grond gegee. Die horisontale waterbeweging is grootliks beperk tot 'n 20 cm radius vanaf die dripper en die waterbeweging was hoofsaaklik in 'n vertikale rigting. Die teenwoordigheid van 'n semi-deurlaatbare grondlaag in die grondprofiel is opgemerk deur water-akkumulasie in die profiel waar te neem. Wortelverspreiding onder die dripper is ook ondersoek en 'n hoë konsentrasie wortels is in die benatte sone gevind. In 'n verdere studie is drie besproeiings/sproeibemestings behandelings gebruik om die invloed van besproeiing/sproeibemesting op grondeienskappe en wortelverspreiding te ondersoek. Die drie behandelings was: mikro-besproeiing (mikro-besproeiing met korrelbemesting), konvensionele-drip-sproeibemesting (daaglikse drip-besproeiing met daaglikse of weeklikse sproeibemesting van 'n ongebalanseerde, voedingsoplossing wat alleenlik uit makro-elemente bestaan) en daaglikse-drip-sproeibemesting (daaglikse drip-besproeiing met daaglikse sproeibemesting van 'n gebalanseerde voedingsoplossing wat mikro- en makro-elemente bevat). Die studie is in twee areas gedoen, een in die Wes-Kaap, op 'n sandgrond, en die ander in die Oos-Kaap, op 'n slik-leemgrond. Mikro-besproeiing: Die wortelverspreidings studies op die sand- en slik-leemgrond wys op 'n wye en eweredige wortelontwikkeling in die totale benatte volume. Op die sand grond is gevind dat die grond pR(KCl)direk onder die sproeiertjie betekenisvol laer was as die pR(KCl)waardes verder weg van die sproeiertjie. Konvensionele-drip-sproeibemesting: Die wortelverspreiding in die sandgrond wys op geringe wortelontwikkeling direk onder die dripper met die hoogste konsentrasie wortels tussen die drippers. Grondversuring en/of suurstoftekorte onder die dripper kan die oorsaak wees van die swak wortelontwikkeling direk onder die dripper. Die grond pR(KCl)direk onder die dripper was betekenisvol laer as die pR(KCl)verder weg van die dripper. In vergelyking met die sandgrond, het die wortels in die slik-leemgrond goed ontwikkelonder die dripper. Dit wil voorkom of versuring en suurstoftekorte onder die dripper nie 'n probleem was in die slik-leemgrond nie. Die res van die wortelstelsel was ook goed ontwikkel. Dit mag wees weens die grond se hoë waterhoudingsvermoë wat 'n groot benatte area tot gevolg het. Daaglikse-drip-sproeibemesting: In die sand grond wil dit voorkom asof die wortels in 'n aaneenlopende kolom onder die dripperlyn ontwikkel met weinig wortelontwikkeling verder as 20 cm van die dripperlyn. Waar oorbesproeiing 'n probleem was, was daar weinig wortelontwikkeling in 'n klein area direk onder die dripper. Die wortel-digtheid in die behandeling was baie hoër as in die ander behandelings. Die gebruik van 'n gebalanseerde voedingsoplossing en puls-besproeiing mag dalk redes wees vir die beter wortelontwikkeling. In die slik-leemgrond is 'n hoë konsentrasie wortels onder die dripper gevind en die res van die wortelstelsel was ook goed ontwikkel. Soos in die konvensionele-drip-sproeibemesting behandeling wil dit voorkom of suurstoftekort en versuring onder die dripper nie 'n probleem was in die grond nie.
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Marla, Sandeep Reddy Huettel Robin Norton. "The effect of cover crops on suppression of nematodes on peanuts and cotton in Alabama." Auburn, Ala, 2008. http://hdl.handle.net/10415/1453.
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Walden, Ronald Francis. "Influences of supraoptimal root-zone temperature on the medium solution and growth of woody nursery crops." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/39733.
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CHIMENTO, CARLO. "ASSESSMENT OF THE CARBON SEQUESTRATION POTENTIAL IN SOIL AND IN BELOWGROUND BIOMASS OF SIX PERENNIAL BIOMASS CROP." Doctoral thesis, Università Cattolica del Sacro Cuore, 2015. http://hdl.handle.net/10280/6072.
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L'obiettivo della ricerca è stato quello di identificare la coltura bioenergetica con il maggior potenziale di sequestro del carbonio (C); sono state considerate tre colture perenni arboree (pioppo, robinia e salice) e tre colture erbacee perenni (canna comune , miscanto e panico ) al sesto anno dal loro impianto e coltivate nello stesso ambiente.
In primo luogo sono state misurate le variazioni dei tassi del C organico del suolo (COS) per il primo 1 m, mentre per i primi 30 cm di suolo è stato stimato il grado di stabilita del COS valutando sette frazioni di COS che presentano differenti gradi di stabilizzazione; in secondo luogo, sono stati caratterizzati gli apparati radicali delle sei specie per la stessa profondità di suolo, per valutare dove le specie accumulano la biomassa radicale lungo il profilo di suolo. I risultati confermano che l’impianto di colture bioenergetiche perenni su superfici precedentemente dedite a colture annuali gestite convenzionalmente rappresenta una opzione valida per sequestrare C nel soulo. Tuttavia, è stata osservata una diversa capacità di sequestro di C tra specie arboree ed erbacee: le specie arboree hanno dimostrato aumentre il contenuto di COS nel primo strato di suolo ( 0-10 cm di suolo), ma la loro capacità di allocare biomassa radicale negli strati profondi del suolo è limitata; mentre, la specie erbacee allocano un’alta quantità di biomassa radicale negli strati profondi del suolo, ma solo il panico ed il miscanto hanno aumentato il contenuto di C nel primo strato di suolo.The objective of the present research was to identify the bioenergy crop with the greatest carbon sequestration potential among three perennial woody crops (poplar, black locust and willow) and three perennial herbaceous crops (giant reed, miscanthus and switchgrass) at the sixth year from plantation and in the same location. First of all the SOC stock variations for the first 1 m soil depth and the quantification of seven soil C fractions related to SOC stabilization level of the first 30 cm of soil were assessed; secondly, a characterization of the root system and the traits which affect the carbon allocation in soil were considered. The results confirm that the establishment of perennial bioenergy crops in previous arable fields can be a suitable option to sequester carbon (C) belowground. However, a different C sequestration capacity was observed between woody and herbaceous crops: woody species showed the greatest SOC sequestration potential in the first soil layer (0-10 cm of soil) but their ability to allocate root biomass in the deeper soil layers was limited; while, the herbaceous species allocated a high amount of root biomass in the deeper soil layers, but only switchgrass and miscanthus sequester C in the first soil layer.
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CHIMENTO, CARLO. "ASSESSMENT OF THE CARBON SEQUESTRATION POTENTIAL IN SOIL AND IN BELOWGROUND BIOMASS OF SIX PERENNIAL BIOMASS CROP." Doctoral thesis, Università Cattolica del Sacro Cuore, 2015. http://hdl.handle.net/10280/6072.
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L'obiettivo della ricerca è stato quello di identificare la coltura bioenergetica con il maggior potenziale di sequestro del carbonio (C); sono state considerate tre colture perenni arboree (pioppo, robinia e salice) e tre colture erbacee perenni (canna comune , miscanto e panico ) al sesto anno dal loro impianto e coltivate nello stesso ambiente.
In primo luogo sono state misurate le variazioni dei tassi del C organico del suolo (COS) per il primo 1 m, mentre per i primi 30 cm di suolo è stato stimato il grado di stabilita del COS valutando sette frazioni di COS che presentano differenti gradi di stabilizzazione; in secondo luogo, sono stati caratterizzati gli apparati radicali delle sei specie per la stessa profondità di suolo, per valutare dove le specie accumulano la biomassa radicale lungo il profilo di suolo. I risultati confermano che l’impianto di colture bioenergetiche perenni su superfici precedentemente dedite a colture annuali gestite convenzionalmente rappresenta una opzione valida per sequestrare C nel soulo. Tuttavia, è stata osservata una diversa capacità di sequestro di C tra specie arboree ed erbacee: le specie arboree hanno dimostrato aumentre il contenuto di COS nel primo strato di suolo ( 0-10 cm di suolo), ma la loro capacità di allocare biomassa radicale negli strati profondi del suolo è limitata; mentre, la specie erbacee allocano un’alta quantità di biomassa radicale negli strati profondi del suolo, ma solo il panico ed il miscanto hanno aumentato il contenuto di C nel primo strato di suolo.The objective of the present research was to identify the bioenergy crop with the greatest carbon sequestration potential among three perennial woody crops (poplar, black locust and willow) and three perennial herbaceous crops (giant reed, miscanthus and switchgrass) at the sixth year from plantation and in the same location. First of all the SOC stock variations for the first 1 m soil depth and the quantification of seven soil C fractions related to SOC stabilization level of the first 30 cm of soil were assessed; secondly, a characterization of the root system and the traits which affect the carbon allocation in soil were considered. The results confirm that the establishment of perennial bioenergy crops in previous arable fields can be a suitable option to sequester carbon (C) belowground. However, a different C sequestration capacity was observed between woody and herbaceous crops: woody species showed the greatest SOC sequestration potential in the first soil layer (0-10 cm of soil) but their ability to allocate root biomass in the deeper soil layers was limited; while, the herbaceous species allocated a high amount of root biomass in the deeper soil layers, but only switchgrass and miscanthus sequester C in the first soil layer.
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Lindeque, Michelle Irene. "Diversity of root nodule bacteria associated with Phaseolus coccineus and Phaseolus vulgaris species in South Africa." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-02162007-170945.
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Montagu, Kelvin D., of Western Sydney Hawkesbury University, Faculty of Agriculture and Horticulture, and School of Horticulture. "Whole plant response to soil compaction : from field practices to mechanisms." THESIS_FAH_HOR_Montagu_K.xml, 1995. http://handle.uws.edu.au:8081/1959.7/433.
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This thesis examines the growth response and inter-relationships between shoots and roots of plants grown in compact soil. In the field, two topsoil and two subsoil conditions were created with five vegetable crops sequentially grown. Between 6 and 12% of the root system grew in the compact subsoil, which had a soil strength of 3.1 c.f. 1.9 MPa in the loosened subsoil. Both the root length density (Lv) and the specific root length were lower in the compact subsoil (80% and 30%, respectively). This had no effect on shoot growth when water and nutrients were well supplied. Compensatory root growth in the lose soil above the compact subsoil occurred in broccoli plants. As a result plants grown in soil with or without a compact subsoil had a similar total root length but with altered root distribution. When the water and nitrogen supplied to the soil was reduced, the lower subsoil Lv in the compact subsoil did not restrict water or N acquisition. This was possibly due to a large increase in the specific uptake per unit length of root, by the fewer roots in the compact subsoil. Compared to the subsoil treatments, only small changes in topsoil physical properties occurred when tillage was ceased. From the field trials the proportion and time of root growth into compact soil appeared important in determining the plant response. In a series of split-root experiments (horizontal and vertical arrangements of compact and loose soil) compensatory root growth in the loose soil only occurred when the root system was exposed to horizontally compact soil When compensatory root growth did not occur shoot growth was reduced. This resulted in there being a close relationship between total root length and leaf area. Further test results support a direct effect of mechanical impedance on shoot growth with a rapid (within 10 minutes) and large (50%) reduction in leaf elongation occurring when roots were mechanically impeded. In the field only plants whose roots were totally exposed to compact soil had reduced shoot growth with very compact subsoil having no effect.Doctor of Philosophy (PhD)
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Hoskins, Tyler Courtney. "Water and nutrient transport dynamics during the irrigation of containerized nursery crops." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/48165.
Full textAbstract:
Increased water- and fertilizer-use-efficiency in containerized crop production, via reduced water loss, enhances crop-available nutrients while reducing non-point source agrichemical contributions in accordance with regulatory standards. Previous studies detailed nutrient leaching patterns throughout crop production seasons, leaving little known about water and dissolved nutrient (solute) movement through soilless substrates during irrigation. The following experiments evaluated fundamental water and solute transport principles through pine-bark based substrates. 1) Ilex crenata Thunb. 'Bennett's Compactum' were grown in 2.7 L containers. Tensiometers detected wetting front (WF) movement throughout the substrate during irrigation. 2) Tracer solution (containing NO3-, PO43- and K+) and deionized water (DI) were applied to substrate-filled columns to characterize tracer breakthrough under saturated and unsaturated conditions. 3) Controlled-release fertilizer (CRF) was topdressed (surface-applied), incorporated (throughout substrate), dibbled (center of substrate) or not applied to fallow substrate, irrigated with DI and leachate analyzed to determine nutrient concentrations throughout irrigation. Tensiometers revealed that seasonal root growth affected substrate pre-irrigation moisture distribution. Wetting fronts channeled through the substrate before becoming thoroughly wetted. Tracer breakthrough occurred with less effluent volume under unsaturated conditions. Breakthrough of NO3- and PO43- was relatively conservative, though 37% of K+ was retained by the substrate. Leachate concentrations for topdressed and incorporated CRF peaked early (first 50mL effluent) before diminishing with continued leaching. Leachate concentrations for dibbled CRF initially increased (first 150mL leachate), plateaued and then diminished. These results show the relative rapidity which water and solutes move through pine-bark during irrigation and demonstrate methods for future research on within-irrigation solute transport.Master of Science
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Mothata, Tshiamo Shilla. "Evaluation and verification of resistance in selected vegetable crops for sustainable root-knot nematode management in developing agriculture / Tshiamo Shilla Mothata." Thesis, North-West University, 2006. http://hdl.handle.net/10394/1667.
Full textAbstract:
Root-knot nematodes, (Meloidogyne species) are a major constraint in vegetable
production systems. These parasites cause high yield losses, particularly in
subsistence farming systems. This study was conducted to establish i) whether
monospecific populations of M. incognita race 2 and M. javanica were used in these
trials by means of molecular identification, ii) determine whether root-knot nematode-resistance
is present in commercially available tomato, green bean, pumpkin and
Brassica genotypes and to iii) verify resistance found. M. incognita race 2 and M.
javanica were identified as monospecific using molecular techniques. Host suitability
trials for the relevant vegetable crops were conducted in a greenhouse. Although
various nematode parameters were used (the number of eggs and 52 per root system
and per gram of roots, number of egg masses and egg-laying females (ELF) per root
system), reproduction factors values [RF = final egg and J2 numbers (Pf)/initial egg
and J2 numbers (Pi)] were used as the main criteria to select for root-knot nematode
resistance. Although substantial variation existed among the relevant vegetable
genotypes with regard to all parameters used, none of these genotypes were immune
to either M. incognita race 2 or M. javanica since these parasites reproduced on all
vegetable genotypes used in this study. However, three tomato and a range of
Brassica genotypes had W-values lower than 1, indicating resistance to M. incognita
race 2. With regard to the verification of M. incognita race 2-resistance in tomato
genotype Rhapsody relative to the susceptible Moneymaker in a microplot trial using
a range of initial inoculation levels, strong relationship existed for both genotypes for
the majority of nematode variables used. These relationships were best described by
non-linear equations. Significantly lower numbers of eggs and J2 in roots, as well as
J2 in soil were obtained for Rhapsody compared to Moneymaker. RF-values were
inversely proportional to initial population density (Pi) for Rhapsody (r = -0.3), while
it increased gradually to Pi for Moneymaker (r = 0.94). A range of Brassica genotypes
were also identified resistance to M. incognita race 2 and M. javanica, respectively,
but none of the green bean and pumpkin screened had RF-values 5 1, indicating
susceptibility to both species.Thesis (M. Environmental Science (Plant Protection))--North-West University, Potchefstroom Campus, 2007.
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Montagu, Kelvin D. "Whole plant response to soil compaction : from field practices to mechanisms." Thesis, View thesis View thesis, 1995. http://handle.uws.edu.au:8081/1959.7/433.
Full textAbstract:
This thesis examines the growth response and inter-relationships between shoots and roots of plants grown in compact soil. In the field, two topsoil and two subsoil conditions were created with five vegetable crops sequentially grown. Between 6 and 12% of the root system grew in the compact subsoil, which had a soil strength of 3.1 c.f. 1.9 MPa in the loosened subsoil. Both the root length density (Lv) and the specific root length were lower in the compact subsoil (80% and 30%, respectively). This had no effect on shoot growth when water and nutrients were well supplied. Compensatory root growth in the lose soil above the compact subsoil occurred in broccoli plants. As a result plants grown in soil with or without a compact subsoil had a similar total root length but with altered root distribution. When the water and nitrogen supplied to the soil was reduced, the lower subsoil Lv in the compact subsoil did not restrict water or N acquisition. This was possibly due to a large increase in the specific uptake per unit length of root, by the fewer roots in the compact subsoil. Compared to the subsoil treatments, only small changes in topsoil physical properties occurred when tillage was ceased. From the field trials the proportion and time of root growth into compact soil appeared important in determining the plant response. In a series of split-root experiments (horizontal and vertical arrangements of compact and loose soil) compensatory root growth in the loose soil only occurred when the root system was exposed to horizontally compact soil When compensatory root growth did not occur shoot growth was reduced. This resulted in there being a close relationship between total root length and leaf area. Further test results support a direct effect of mechanical impedance on shoot growth with a rapid (within 10 minutes) and large (50%) reduction in leaf elongation occurring when roots were mechanically impeded. In the field only plants whose roots were totally exposed to compact soil had reduced shoot growth with very compact subsoil having no effect.
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Inácio, Marielle Cascaes [UNESP]. "Fatores ambientais e fenológicos na atividade antimicrobiana e produção de ativos em Cochlospermum regium (Schrank) Pilg." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/103396.
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000756284.pdf: 2013969 bytes, checksum: d7866691c0ef92e24e225b1ece791701 (MD5)A espécie Cochlospermum regium foi selecionada por apresentar importantes propriedades terapêuticas relacionadas a infecções do sistema reprodutivo feminino, relatadas em levantamentos etnofarmacológicos. Entretanto, alguns estudos realizados com microorganismos in vitro são contraditórios. Este fato pode estar relacionado a fatores ambientais e fenológicos referentes ao cultivo da planta, a forma de preparação dos extratos e/ou também ao microrganismo alvo. No presente trabalho foram avaliadas a atividade antimicrobiana em raízes de plantas de C. regium coletadas em diversas localidades, estádios fenológicos, idade da planta e condições de sazonalidade. Para realização destes testes antimicrobianos foi desenvolvida uma metodologia a qual utiliza diretamente a droga vegetal sem a necessidade prévia de preparação de extratos (STAMP). Além disso, foram realizados estudos fitoquímicos biomonitorados através da bioautografia. Quanto ao STAMP, constatou-se que este é eficiente para avaliar drogas vegetais principalmente com atividade antifúngica. Com relação aos testes que avaliaram o efeito ambiental e fenológico sobre a atividade antimicrobiana de raízes de C. regium, foi verificado que, apesar de a planta apresentar atividade antimicrobiana em todas as condições avaliadas, foi possível observar que as raízes coletadas no outono e inverno apresentaram maior inibição frente a C. albicans, além disso, a idade da planta e substrato de cultivo, também interferem nesta resposta biológica. Desta maneira, para utilização de extratos desta planta contra essa doença infecciosa causada por C. albicans, recomenda-se a coleta de plantas no outono e inverno. Também foi possível observar que a entrecasca e cerne da raiz são os principais responsáveis pela atividade antimicrobiana. Os estudos fitoquímicos, realizados a partir do extrato hidroalcoólico (80%)...
Cochlospermum regium was selected because it has important therapeutic properties related to infections of female reproductive system, which is reported in ethnopharmacological studies. However, some studies with microorganisms in vitro using this plant are contradictory. This fact could be related to environmental or phenological factors relating to the cultivation of the plant, how to prepare the extracts and/or also the target organism. In this study has been evaluated the antimicrobial activity of C. regium roots collected in different localities, growth stages, plant age and seasonal conditions. To conduct these antimicrobials tests, a methodology has developed which uses the powered plant directly without prior preparation of extracts (STAMP). In addition, biomonitored phytochemical analysis were performed by bioautography assays. Regarding STAMP method, it was efficient for evaluating powered plant mainly with antifungal activity. The tests that evaluated the environmental and phenological effects on the antimicrobial activity of C. regium roots showed that despite the plant antimicrobial activity occur in all conditions evaluated, it has observed that the roots collected in autumn and winter showed greater inhibition against C. albicans. Furthermore, the age of the plant and the substrate of culture also affect the biological response. Thus, we recommend collecting plants in autumn and winter to use against infectious disease caused by C. albicans. It has also observed that both inner bark and root cern are the main responsible for the antimicrobial activity. The phytochemical studies, carried out from the hydroalcoholic extract (80%), showed that the active compounds are of medium polarity, since the highest activity has obtained in the ethyl acetate fraction. Gallic acid was found to be the majority compound 4 in this fraction from GC-MS. Two flavonoids have isolated in ...
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Inácio, Marielle Cascaes 1985. "Fatores ambientais e fenológicos na atividade antimicrobiana e produção de ativos em Cochlospermum regium (Schrank) Pilg /." Botucatu:, 2013. http://hdl.handle.net/11449/103396.
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Orientador: Ana Maria Soares PereiraCoorientador: Bianca Waléria Bertoni
Banca: Glyn Mara Figueira
Banca: Rosa de Belem das Neves Alves
Banca: Lin Chau Ming
Banca: Elzabeth Orika Ono
Resumo: A espécie Cochlospermum regium foi selecionada por apresentar importantes propriedades terapêuticas relacionadas a infecções do sistema reprodutivo feminino, relatadas em levantamentos etnofarmacológicos. Entretanto, alguns estudos realizados com microorganismos in vitro são contraditórios. Este fato pode estar relacionado a fatores ambientais e fenológicos referentes ao cultivo da planta, a forma de preparação dos extratos e/ou também ao microrganismo alvo. No presente trabalho foram avaliadas a atividade antimicrobiana em raízes de plantas de C. regium coletadas em diversas localidades, estádios fenológicos, idade da planta e condições de sazonalidade. Para realização destes testes antimicrobianos foi desenvolvida uma metodologia a qual utiliza diretamente a droga vegetal sem a necessidade prévia de preparação de extratos (STAMP). Além disso, foram realizados estudos fitoquímicos biomonitorados através da bioautografia. Quanto ao STAMP, constatou-se que este é eficiente para avaliar drogas vegetais principalmente com atividade antifúngica. Com relação aos testes que avaliaram o efeito ambiental e fenológico sobre a atividade antimicrobiana de raízes de C. regium, foi verificado que, apesar de a planta apresentar atividade antimicrobiana em todas as condições avaliadas, foi possível observar que as raízes coletadas no outono e inverno apresentaram maior inibição frente a C. albicans, além disso, a idade da planta e substrato de cultivo, também interferem nesta resposta biológica. Desta maneira, para utilização de extratos desta planta contra essa doença infecciosa causada por C. albicans, recomenda-se a coleta de plantas no outono e inverno. Também foi possível observar que a entrecasca e cerne da raiz são os principais responsáveis pela atividade antimicrobiana. Os estudos fitoquímicos, realizados a partir do extrato hidroalcoólico (80%) ...
Abstract: Cochlospermum regium was selected because it has important therapeutic properties related to infections of female reproductive system, which is reported in ethnopharmacological studies. However, some studies with microorganisms in vitro using this plant are contradictory. This fact could be related to environmental or phenological factors relating to the cultivation of the plant, how to prepare the extracts and/or also the target organism. In this study has been evaluated the antimicrobial activity of C. regium roots collected in different localities, growth stages, plant age and seasonal conditions. To conduct these antimicrobials tests, a methodology has developed which uses the powered plant directly without prior preparation of extracts (STAMP). In addition, biomonitored phytochemical analysis were performed by bioautography assays. Regarding STAMP method, it was efficient for evaluating powered plant mainly with antifungal activity. The tests that evaluated the environmental and phenological effects on the antimicrobial activity of C. regium roots showed that despite the plant antimicrobial activity occur in all conditions evaluated, it has observed that the roots collected in autumn and winter showed greater inhibition against C. albicans. Furthermore, the age of the plant and the substrate of culture also affect the biological response. Thus, we recommend collecting plants in autumn and winter to use against infectious disease caused by C. albicans. It has also observed that both inner bark and root cern are the main responsible for the antimicrobial activity. The phytochemical studies, carried out from the hydroalcoholic extract (80%), showed that the active compounds are of medium polarity, since the highest activity has obtained in the ethyl acetate fraction. Gallic acid was found to be the majority compound 4 in this fraction from GC-MS. Two flavonoids have isolated in ...
Doutor
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Sheumack, Michele Denise, and n/a. "StarLink(TM) Corn: A Case Study." Griffith University. School of Science, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040401.151800.
Full textAbstract:
The 18 September 2000 disclosure that StarLink corn, a genetically engineered variety not approved for human consumption, had been detected in food was a seminal event in agricultural biotechnology. This thesis presents a comprehensive case study of the StarLink incident (part one), reviews the StarLink situation in terms of crisis management theory (part two) and develops crisis management theory using the StarLink incident as an example of a crisis (part three). Part one provides background information, then a meticulous day-by-day account of StarLink-related events. Part two presents a detailed overview of crisis management theory, then examines the StarLink situation in terms of pre-crisis (warning signals, preconditions for a crisis, crisis trigger), crisis (how Aventis, the biotechnology provider, managed the crisis and opinions concerning crisis handling) and post-crisis (lessons learned). Part three develops crisis management theory using the StarLink situation as an example of a crisis. It evaluates whether the StarLink incident possessed characteristics predicted for modern crises and suggests other factors which may become more prevalent and significant in future crises. The StarLink incident delivers certain practical lessons for managers, regulators and others and demonstrates a number of characteristics of modern crises.
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Ratnasoma, H. A. "Studies on the use of Pasteuria penetrans for control of root-knot nematodes and its field evaluation on perennial crops in Sri Lanka." Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253457.
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Sande, Bueno Dickens. "Pollarding and root pruning as management options for tree-crop competition and firewood production." Thesis, Stellenbosch : University of Stellenbosch, 2003. http://hdl.handle.net/10019.1/2355.
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Thesis (MScFor) (Forest and Wood Science)--University of Stellenbosch, 2003.Planting of upperstorey trees along boundaries has been introduced in KabaleUganda with good reception from local farmers. Trees have been planted along agricultural fields, but both Alnus acuminata and Grew/lea robusta out-compete food crops. Managing competition between trees and crops for water, light, and nutrients to the benefit of farmers is a determinant of successful agroforestry. The scarcity and fragmentation of farmland coupled with the hilly nature of Kabale, highlights the need to address the question of tree-crop competition for resources if the technology of on-farm tree planting is to be widely disseminated and adopted in its different guises. Five-year old trees of A acuminata and G. robusta were subjected to treatments of pollarding, or a combination of pollarding and one side root pruning and compared with unpruned controls. The objectives were to assess their potential in reducing competition with food crops and providing firewood to farmers as well as their effects on tree growth. Pollarding has many benefits to farmers because it provides firewood and stakes for climbing beans, it reduces competition for resources between trees and crops and enables continued tree planting on-farm. Continued on-farm tree planting alleviates problems associated with limited land and contributes to environmental resilience. To ensure this, effect of pollarding and root pruning of upperstorey boundary trees of A acuminata and G. robusta was tested on 12 farmers' fields in Kabale. Food crops (beans and maize) grown in the sequence beans-maize-beans, grew very well at less than 50 em from trees that had been pollarded and root pruned one side. In general, pooled data from 12 sites over 5 m away from trees indicated that a combination of pollarding and root pruning increased bean yield by 240% and maize by 154%, while pollarding alone increased bean yield by 181% and maize yield was increased by 123% in comparison to non-pruned trees. However, pollarding and root pruning treatments reduced tree growth rates.Notable was more competition with crops by A. acuminata than by G. robusta. This was attributed to differences in root architecture, diameter at breast height (dbh) sizes, crown spread and crown density between the two species. Five-year-old A. acuminata had bigger dbh (12.40 cm), wider crown spread (6 m) and a dense crown, while G. robusta had dbh 10.82 em, 3 m crown spread and a light crown. A. acuminata also had more branches per tree (34) compared to G. robusta with only 25. These factors influence water uptake, light penetration through the canopy and transpiration rates, and thus affect tree-food crop competition. It is concluded that pollarding and root pruning have a great potential to reduce tree-crop competition, thereby paving the way for continued on-farm tree planting. The effect of pollarding on timber quality, moisture seepage into timber through the cut surface, if any, and the extent of its damage are areas for further research. The rate of root recovery is also to be followed closely to determine an appropriate frequency for cutting back of roots to recommend to farmers how often they need to prune their trees. It is also suggested that a thorough study be conducted on the amount of water uptake from the soil by each of the species Alnus acuminata and Grevillea robusta. This will help further explain the differences in competition between the two species.
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Olibone, Ana Paula Encide [UNESP]. "Ciclagem de nutrientes em sistemas de rotação de culturas." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/99999.
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olibone_ape_dr_botfca.pdf: 3141451 bytes, checksum: 841b3864f5b41bea3ef33884436e0802 (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
As espécies utilizadas em sistemas de rotação de culturas comportamse de maneira diferente quanto à absorção e ciclagem de nutrientes. Além disso, a absorção de nutrientes é influenciada pelas propriedades físicas do solo, capazes de modificar o crescimento e desenvolvimento radicular. O presente trabalho teve como objetivo estudar a ciclagem de nutrientes em três sistemas de rotação de culturas, relacionando-a à atividade radicular da braquiária e sorgo, em sistema de semeadura direta, escarificado (SDCE) e sem escarificação (SDSE), em Nitossolo Vermelho de textura argilosa na cidade de Botucatu-SP. Além das plantas de cobertura também se avaliou a atividade radicular das culturas do milho e da soja. O sistema de rotação foi implantado na safra de 2005/2006 como segue: (1) milheto / soja / sorgo / milho / sorgo/ soja; (2) milheto / soja / braquiária / milho / braquiária / soja e (3) milheto / soja / mamona + braquiária / milho / mamona + braquiária / soja. O delineamento experimental foi o de blocos ao acaso com quatro repetições em parcelas subdivididas. A condução do experimento deu-se por dois anos agrícolas (2006/2007; 2007/2008) para possível observação de algum efeito acumulativo dos tratamentos. A atividade radicular das plantas de cobertura (novembro 2006), do milho (fevereiro 2007) e da soja (dezembro 2007) foi avaliada indiretamente, usando-se rubídio como marcador. Aplicou-se 3 mL da solução de nitrato de rubídio no solo com cateter, a 0,05; 0,10; 0,20, 0,40 e 0,60 m de profundidade e a 0,11 e 0,22 m de distância da planta de referência. Decorrido 4 dias da aplicação, coletou-se as respectivas partes aéreas das plantas, as quais foram secas, moídas e digeridas por via úmida para determinação do teor de rubídio em absorção atômica. Também foram analisadas...
The species used in crop rotation systems differ in nutrient absorption and cycling. Moreover, nutrient absorption is influenced by soil physical properties, which may affect root growth and its development. The present research had as objective to investigate nutrient cycling in three crop rotation systems and its relation to root activity of Brachiaria and sorghum in no tillage system, with and without chiselling. The experiment was carried out in Botucatu, SP, Brazil, in a Red Nitosol, with clay texture. The rotation system was implemented in 2005/2006 and carried out for two growing seasons (November of 2006 and 2007). Crop rotation systems were: (1) Pearl millet / soybean / sorghum / maize / sorghum / soybean; (2) Pearl millet / soybean / Brachiaria / maize / Brachiaria / soybean and (3) Pearl millet / soybean / Brachiaria + castor bean / maize / Brachiaria + castor bean / soybean. The experimental design was the completely randomized block with split-plots and four replications. Root activity was evaluated for either cover crops or maize and soybean. Root activity of cover crops (November of 2006 and 2007), maize (February of 2007) and soybean (December of 2007) was indirectly evaluated, using Rubidium as marker. The solution of 3 mL of rubidium nitrate was applied in soil with a catheter, at 0.05, 0.10, 0.20, 0.40 and 0.60 m depths and at 0.11 and 0.22 m away from the plant in question. The respective shoots were collected, dried, grounded and submitted to humid digestion 4 days after the application to evaluate rubidium level through atomic absorption. Chemical characteristics and soil penetration resistance were also evaluated at 0.00-0.05, 0.05-0.10, 0.10-0.20, 0.20-0.40 and 0.40-0.60 m depths in the respective growing seasons. According to Rb levels observed in dry matter, the highest... (Complete abstract click electronic access below)
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Martin, Dana. "Investigation of the Biocontrol Activity in vitro and in planta of Different Pseudomonas Species Against Important Crown, Stem, Foliar and Root Pathogens of Ornamental Crops." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503063395390704.
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Fabiani, Mirian Fracasso. "Germinação de sementes e crescimento de plântulas de milho e soja afetados por palha e extrato aquoso de culturas de inverno." Universidade do Estado de Santa Catarina, 2016. http://tede.udesc.br/handle/handle/2387.
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Plants and other organisms can release primary and secondary metabolites from the leaves, roots and other plant parts, whose effects are studied in the field of allelopathy. The study of allelopathy is a field on the rise and of great importance to enable the researcher to identify possible causes of success or failure in development of a given crop. The aim of this study was to determine whether the plant residues of wheat, rye and oats in different amounts (50, 100 and 150%) and its aqueous extracts of fresh mass of shoots of wheat, rye and oats in different concentrations (0, 1 10, 25, 50 and 100 ml-1) affect seed germination and early growth of corn plants and soybeans. The first experiment was conducted in a growth chamber, where the shoots of winter crops was packed to the soil in pots, and later planted corn and soybeans. The second experiment was conducted in the laboratory by preparing aqueous extracts of wheat, rye and oats and tested on corn and soybean seeds. Sowing of maize and soybeans in soils with the presence of vegetable residues of wheat, mainly in the amount of 50% of weight, reduced seed germination and early seedling growth. The aqueous extracts of the three winter crops not adversely affected the germination and early growth of corn and soybeans, and the shoot length and root influenced according to the concentration used. It was concluded that seed germination and early growth of corn and soybean seedlings are influenced by the presence of fresh weight of winter crops, and with the shoot length and dry mass, and dependent on the type of waste used.
As plantas e os demais organismos podem liberar metabólitos primários e secundários a partir das folhas, raízes e outras partes da planta, cujo os efeitos são estudados no campo da alelopatia. O estudo da alelopatia é um campo em ascensão e de grande importância, ao possibilitar o pesquisador identificar possíveis causas do sucesso ou insucesso no desenvolvimento de determinada cultura agrícola. O objetivo deste estudo foi verificar se os resíduos vegetais de trigo, azevém e aveia em diferentes quantidades (50, 100 e 150%) e seus extratos aquosos da massa fresca de parte aérea de trigo, azevém e aveia em diferentes concentrações (0, 1, 10, 25, 50 e 100 mL-1) influenciam a germinação de sementes e o crescimento inicial de plântulas de milho e soja. O primeiro experimento foi realizado em câmara de crescimento, onde a parte aérea das culturas de inverno foi acondicionada ao solo, em vasos, sendo posteriormente semeados milho e soja. O segundo experimento foi conduzido em laboratório através da elaboração de extratos aquosos das culturas de trigo, azevém e aveia e testados sobre as sementes de milho e soja. A semeadura de milho e soja em solo com a presença de resíduos vegetais de trigo, principalmente, na quantidade de 50% de massa fresca, reduziu a germinação de sementes e o crescimento inicial das plântulas. Os extratos aquosos das três culturas de inverno não influenciam negativamente a germinação e o crescimento inicial do milho e da soja, sendo o comprimento de parte aérea e de raiz influenciada de acordo com a concentração utilizada. Conclui-se que a germinação das sementes e o crescimento inicial das plântulas de milho e soja são influenciadas pela presença de massa fresca das culturas de inverno, assim com o comprimento de parte aérea e massa seca, sendo dependentes do tipo de resíduo utilizado
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Olibone, Ana Paula Encide 1978. "Ciclagem de nutrientes em sistemas de rotação de culturas /." Botucatu : [s.n.], 2008. http://hdl.handle.net/11449/99999.
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Orientador: Ciro Antonio RosolemBanca: Dirceu Maximono Fernandes
Banca: Salatier Buzetti
Banca: Julinano Carlos Calonego
Banca: Gedi Jorge Sfredo
Resumo: As espécies utilizadas em sistemas de rotação de culturas comportamse de maneira diferente quanto à absorção e ciclagem de nutrientes. Além disso, a absorção de nutrientes é influenciada pelas propriedades físicas do solo, capazes de modificar o crescimento e desenvolvimento radicular. O presente trabalho teve como objetivo estudar a ciclagem de nutrientes em três sistemas de rotação de culturas, relacionando-a à atividade radicular da braquiária e sorgo, em sistema de semeadura direta, escarificado (SDCE) e sem escarificação (SDSE), em Nitossolo Vermelho de textura argilosa na cidade de Botucatu-SP. Além das plantas de cobertura também se avaliou a atividade radicular das culturas do milho e da soja. O sistema de rotação foi implantado na safra de 2005/2006 como segue: (1) milheto / soja / sorgo / milho / sorgo/ soja; (2) milheto / soja / braquiária / milho / braquiária / soja e (3) milheto / soja / mamona + braquiária / milho / mamona + braquiária / soja. O delineamento experimental foi o de blocos ao acaso com quatro repetições em parcelas subdivididas. A condução do experimento deu-se por dois anos agrícolas (2006/2007; 2007/2008) para possível observação de algum efeito acumulativo dos tratamentos. A atividade radicular das plantas de cobertura (novembro 2006), do milho (fevereiro 2007) e da soja (dezembro 2007) foi avaliada indiretamente, usando-se rubídio como marcador. Aplicou-se 3 mL da solução de nitrato de rubídio no solo com cateter, a 0,05; 0,10; 0,20, 0,40 e 0,60 m de profundidade e a 0,11 e 0,22 m de distância da planta de referência. Decorrido 4 dias da aplicação, coletou-se as respectivas partes aéreas das plantas, as quais foram secas, moídas e digeridas por via úmida para determinação do teor de rubídio em absorção atômica. Também foram analisadas... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract : The species used in crop rotation systems differ in nutrient absorption and cycling. Moreover, nutrient absorption is influenced by soil physical properties, which may affect root growth and its development. The present research had as objective to investigate nutrient cycling in three crop rotation systems and its relation to root activity of Brachiaria and sorghum in no tillage system, with and without chiselling. The experiment was carried out in Botucatu, SP, Brazil, in a Red Nitosol, with clay texture. The rotation system was implemented in 2005/2006 and carried out for two growing seasons (November of 2006 and 2007). Crop rotation systems were: (1) Pearl millet / soybean / sorghum / maize / sorghum / soybean; (2) Pearl millet / soybean / Brachiaria / maize / Brachiaria / soybean and (3) Pearl millet / soybean / Brachiaria + castor bean / maize / Brachiaria + castor bean / soybean. The experimental design was the completely randomized block with split-plots and four replications. Root activity was evaluated for either cover crops or maize and soybean. Root activity of cover crops (November of 2006 and 2007), maize (February of 2007) and soybean (December of 2007) was indirectly evaluated, using Rubidium as marker. The solution of 3 mL of rubidium nitrate was applied in soil with a catheter, at 0.05, 0.10, 0.20, 0.40 and 0.60 m depths and at 0.11 and 0.22 m away from the plant in question. The respective shoots were collected, dried, grounded and submitted to humid digestion 4 days after the application to evaluate rubidium level through atomic absorption. Chemical characteristics and soil penetration resistance were also evaluated at 0.00-0.05, 0.05-0.10, 0.10-0.20, 0.20-0.40 and 0.40-0.60 m depths in the respective growing seasons. According to Rb levels observed in dry matter, the highest... (Complete abstract click electronic access below)
Doutor
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Andrade, Júnior Oscar de. "Estudo da composição tecnológica e bromatológica de mandioca (Manihot esculenta Crantz) em dois espaçamentos." Universidade do Oeste Paulista, 2006. http://bdtd.unoeste.br:8080/tede/handle/tede/406.
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Previous issue date: 2006-01-31The cassava (Manihot esculenta Crantz) is currently of great economic and social importance for Brazil. Important factors for evaluation of cassava cultivars under field conditions are: productivity (mg ha-1); Dry Matter Percentage (MS%). In order to carry out nutritional evaluation the following parameters must be considered: Fat - Ethereal Extract (EE%); Ash (%); Gross Digective Fiber (FB%); Gross Protein (PB%); Non Nitrogenate Extrative (ENN%) and Total Digestive Nutrient (NDT). The aim of this study was to verify differences between 16 cassava cultivars cultivates whit differents spacements: 0,60 m and 0,80 m whithin the line and 0,90 m between lines. The experimental design performed in random blocks with some treatments in common, with four repetitions. The results showed that the cultivars Espeto; Eucalipto e IAC 144-86 obtained smaller productivities. The cultivars Iracema; IAC 184-89; Fibra; IAC 89-87; Fécula Branca; IAC 32-88; IAC 14; Olho Junto; Mico; IAC 12; IAC 169-86; IAC 5-88; IAC 15 showed the highest yields. The bromatological characteristics didn't present statistical differences. The among cultivars 0,60m in the spacement increased the productivity in 12% when compared to the 0,80m spacement.
A mandioca (Manihot Esculenta Crantz) é atualmente de grande importância econômica e social para o Brasil. Fatores importantes para avaliação de cultivares de mandioca a campo são: produtividade (Mg ha-1) e o teor de Matéria Seca (MS%). Para avaliação nutricional deve-se atentar para: Gordura Extrato Etéreo (EE%); Cinza (%); Fibra Bruta (FB%); Proteína Bruta (PB%); Extrativo Não Nitrogenado (ENN%) e Nutrientes Digestivo Totais (NDT%). O presente trabalho objetivou estudar as diferenças entre cultivares de mandioca, com espaçamentos de 0,60m e 0,80m na linha e 0,90m na entre linhas. O delineamento experimental utilizado foi análise conjunta de experimentos em blocos ao acaso com alguns tratamentos em comuns, com quatro repetições. Conclui-se, no presente ensaio que as cultivares Espeto; Eucalipto e IAC 144-86, obtiveram menores produtividades estatisticamente; As cultivares Iracema; IAC 184-89; Fibra; IAC 89-87; Fécula Branca; IAC 32-88; IAC 14; Olho Junto; Mico; IAC 12; IAC 169-86; IAC 5-88; IAC 15 obtiveram as melhores produtividades estatisticamente; As características bromatológicas não apresentaram diferenças estatísticas; O espaçamento de 0,60m aumentou a produtividade em 12% quando comparado ao espaçamento de 0,80m
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Brancalião, Sandro Roberto [UNESP]. "Alterações de propriedades físicas e químicas e das frações húmicas de um nitossolo vermelho na sucessão milheto-soja em semeadura direta." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/99969.
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brancaliao_sr_dr_botfca.pdf: 1373956 bytes, checksum: 1e926e113d10f2a0394a14dd71456450 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O experimento, conduzido em Nitossolo Vermelho distroférrico, na Fazenda Experimental Lageado-FCA-UNESP-Botucatu, , teve por objetivo estudar no sistema de semeadura direta as prováveis alterações das propriedades físicas e químicas e das frações húmicas do solo, através da utilização da cultura do milheto em pré-safra a cultura da soja, em três épocas de semeadura e sob cinco manejos da fitomassa. O delineamento experimental foi o de blocos casualizados, com esquema de parcelas subdivididas, com quatro repetições. As parcelas foram representadas por três épocas de semeadura da cultura do milheto (E1, E2 e E3). As subparcelas foram representadas por manejos da ceifa da fitomassa, sendo: Manejo 1 (M1) - ceifa a cada florescimento e retirada da fitomassa; manejo 2 (M2) - ceifa a cada florescimento e permanência da fitomassa; manejo 3 (M3) - ceifa no florescimento e retirada da fitomassa; manejo 4 (M4) - ceifa no florescimento e permanência da fitomassa e manejo 5 (M5) - livre crescimento. Foram coletadas amostras de solo com estrutura deformada e indeformada para a realização das análises físicas e químicas. Tanto para a análise física quanto para a química, as mesmas profundidades foram amostradas: 0-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,40 m. Para o fracionamento químico da matéria orgânica, amostrou-se de 0-0,05 e 0,05-0,10 m. Em relação 2 as culturas avaliou-se a altura de plantas e a produtividade da soja e para o milheto, o seu sistema radicular, a quantidade de massa seca produzida pela parte aérea e a porcentagem de fitomassa em cobertura deixada sobre o solo. A produtividade de massa de matéria seca foi maior na primeira época de semeadura, excetuando-se o M3 para a segunda época e do M2 para a terceira época de semeadura. A segunda época de semeadura proporcionou maior fitomassa em cobertura...
This work was carried out at Lageado Experimental Station' FCA' Unesp' Botucatu, from October 2001 until April 2004, consisting in a millet' soybean succession, in a no-tillage system, at three sowing, and the aim was evaluate the physicals and chemicals and humics fractions of a Nitossolo Vermelho Distroférrico. The experimental design used was randomized blocks, in a split-plot schedule with four replications, having the sowing (S1, S2, S3) as parcel and harvest handling as subparcel. Where the harvest handling were 1 (H1)' harvest each blooming and covering withdrawal; 2 (H2)' harvest each blooming and covering permanency; 3 (H3)' only in the first harvest on blooming and covering withdrawal; H4 - only in the first harvest on blooming and covering permanency, and H5 'free growing, with no harvest. Disturbed and undisturbed samples were collected from four soil layers (0-0,05, 0,05-0,10 and 0,10-0,20 m) to evaluate the physical and chemical properties. The physical parameters measured were: bulk density, total porosity, macroporosity, microporosity, total clay, disperse clay, floculation degree, aggregation stability (dry sieving) and penetration resistance (Compact Test); the chemicals was: pH, organic mater, exchangele basis (Ca, Mg, K), cationic exchangeable capacity (CEC) and the quantification of the humic fractions (C-AH, C-AF and C-HU) All the parameters were performed on Department of Natural Research's (Soil Science-FCA), in different depths 0-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,40 m. About the humic fractions were analyseds only 0-0,05 e 0,05-0,10 m. The pearl millet matter drought mass productivity decreased in the order S1 > S2 >S3. The soil cover provided by fitomassa of milheto was larger in the S2 > S2 and S3 and in the H4 (with only fitomassa cut and permanence)... (Complete abstract, click eletronic address below)
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SILVA, Hiran Marcelo Siqueira da. "Caracterização do solo e do sistema radicular em pastagens de Pennisetum purpureum schum. manejadas sob diferentes intensidades de manejo em Itambé-PE." Universidade Federal Rural de Pernambuco, 2013. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6821.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
The physical properties of the soil can be affected by stocking rate. When stocking rates are applied correctly can provide favorable environment for root growth. Nitrogen fertilization can also stimulate growth and root activity. Thus, the replacement nitrogen ecosystem grazing results in higher biomass production and more efficient absorption of the nutrients in the soil. Manipulation in stocking and fertilization interfere in the processes of decomposition of plant tissue affecting nutrient cycling in pasture ecosystems. The study was conducted at the Experimental Station of the Agronomic Institute of Pernambuco in Itambé for two years (2009-2010). The experimental treatments consisted of three stocking rates (2.0, 3.9 and 5.8 AU ha-1, 1 AU = 450 kg BW) and three nitrogen levels (0, 150 and 300 kg ha-1 N year-1) grazing elephant grass (Pennisetum purpureum Schum.). Treatments were replicated three times and used a randomized block design in a split plot arrangement. Therefore, the objective was to evaluate the effect of nitrogen fertilization and stocking rate on physical and chemical attributes of the soil, the root distribution in depth and decomposition of roots grazing elephant grass. For part of soil and destruction of root was determined soil bulk density, particle density, porosity, aggregate stability, infiltration rate of the soil water, the light fraction of soil organic matter, soil fertility in depth, root length density and root biomass. For the decomposition analysis, we used the simple exponential model for percentage of disappearance of biomass remaining N (%). The two stage model ("plateau linear") was used to describe ON, NIDA, N and LIG: N throughout the incubation period. The increased stocking rate resulted in higher densities of soil ranging from 1.42 to 1.58 g cm-3. The light fraction of soil organic matter decreased with increasing stocking rate. The aggregation index increased with depth with values of 42.07, 47.75 and 51.04% for the soil layers 0-2.5, 2.5-7.5 and 7.5-15 cm, respectively . Soil fertility also varied at 0-20, 20-40, 40-60, 60-80 and 80-100 cm. The root length had an effect between depths. In the 0-20 cm layer was longest of all types of roots (thin, thick and full). The decomposition of biomass in the second period (10-11) was higher in the first period (9-10). After 512 days of incubation, the biomass remaining in the first period was 40% whereas in the second period was 30%. The C: N ratio dropped to two periods over the 512 days of incubation, however, as they were passing incubation times, the C: N ratio for the second period fell faster (k = 0.00168 g g-1 day-1) compared to the first period (k = 0.00113 g g-1 day-1). The lignin content increased during the incubation time. At time zero, the lignin content in the first period was higher (~ 17%) found for the second period (~ 10%). The stabilization of lignin in the first period was only achieved after 240 days of decomposition with final value of 22%, whereas in the second period, stabilization was reached after 118 days of incubation with final value of approximately 20%. At the end of two years experimental treatments, stocking rate and nitrogen fertilization did not affect Pt, VIB and EA nor influenced the fertility of the soil, the root distribution and root residue decomposition during the trial period. Moreover, the stocking rate modified the soil density and light fraction organic matter. Nitrogen rates interfered with mineralization of N from the root stock.
As propriedades físicas do solo podem ser afetadas pela taxa de lotação animal. Quando as taxas de lotação animal são aplicadas de forma correta podem proporcionar ambiente favorável ao crescimento do sistema radicular. A adubação nitrogenada também pode estimular o crescimento e a atividade radicular. Sendo assim, a reposição nitrogenada em ecossistema de pastagem resulta em maior biomassa produzida e absorção mais eficiente dos nutrientes no solo. A manipulação na lotação e a adubação interferem nos processos de decomposição do tecido vegetal, afetando a ciclagem dos nutrientes nos ecossistemas de pastagem. O estudo foi realizado na Estação Experimental do Instituto Agronômico de Pernambuco em Itambé por dois anos (2009-2010). Os tratamentos experimentais consistiram de três taxas de lotação animal (2, 3,9 e 5,8 UA ha-1; 1 UA = 450 kg PV) e três níveis de adubação nitrogenada (0, 150 e 300 kg N ha-1ano-1) em pastagens de capim-elefante (Pennisetum purpureum Schum.). Os tratamentos foram repetidos três vezes, sendo utilizado o delineamento em blocos casualizados em arranjo de parcelas subdivididas. Sendo assim, objetivou-se avaliar o efeito da adubação nitrogenada e da taxa de lotação nos atributos físicoquímicos do solo, na distribuição de raízes em profundidade e na decomposição das raízes em pastagens de capim-elefante. Para a parte de solo e distribuição de raiz em profundidade foram determinados: a densidade do solo, densidade das partículas, porosidade total, estabilidade de agregados, infiltração básica de água no solo, a fração leve da matéria orgânica do solo, fertilidade do solo em profundidade, a densidade de comprimento de raiz e a biomassa radicular. Para a análise de decomposição, foi utilizado o modelo exponencial simples para porcentagem de desaparecimento de biomassa, N remanescente (%). O modelo de dois estágios (“plateau linear”) foi utilizado para descrever LIG, NIDA, N e LIG:N ao longo do período de incubação. O aumento da taxa de lotação resultou em maiores densidades do solo que variou de 1,42 a 1,58 g cm-3. A fração leve da matéria orgânica do solo reduziu com o aumento da lotação animal. O índice de agregação aumentou com a profundidade, com valores de 42,07, 47,75 e 51,04% para as camadas de solo 0-2,5, 2,5-7,5 e 7,5-15 cm, respectivamente. A fertilidade do solo também variou nas camadas de 0-20, 20-40, 40-60, 60-80 e 80-100 cm. O comprimento de raiz apresentou efeito entre as profundidades. Na camada de 0-20 cm houve maior comprimento de todos os tipos de raízes (fina, grossa e total). A decomposição da biomassa no segundo período experimental (10-11) foi maior ao primeiro período (9-10). Após 512 dias de incubação, a biomassa remanescente no primeiro período foi de 40%, enquanto que no segundo período foi de 30%. A relação C:N caiu para os dois períodos experimentais no decorrer dos 512 dias de incubação, no entanto, à medida que foram passando os tempos de incubação, a relação C:N para o segundo período caiu mais rapidamente (k=0,00168 g g-1 dia-1), se comparado ao primeiro período (k=0,00113 g g-1 dia-1). O teor de lignina aumentou durante o tempo incubação. No tempo zero, o teor de lignina no primeiro período foi superior (~17%) ao encontrado para segundo período (~10%). A estabilização da lignina, no primeiro período, só foi alcançada aos 240 dias de decomposição com valor final de 22%, enquanto que no segundo período a estabilização foi alcançada aos 118 dias de incubação com valor final aproximado de 20%. Ao final de dois anos experimentais os tratamentos, taxa de lotação e adubação nitrogenada não alteraram a Pt, VIB e o EA, nem tão pouco influenciaram os parâmetros de fertilidade do solo, a distribuição do sistema radicular e na decomposição do resíduo radicular no período experimental. Por outro lado, a taxa de lotação modificou a densidade do solo e a fração leve da matéria orgânica. As doses de nitrogênio interferiram na mineralização do estoque de N da raiz.
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Matheron, M. E., and R. E. Call. "Field Testing of Potential New Fungicides for Control of Phytophthora Root and Crown Rot of Chile Pepper." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/214719.
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Root and crown rot and blight of chile peppers is caused by the soil -borne plant pathogenic fungus Phytophthora capsici. The root and crown rot phases of the disease are favored by saturated soil conditions, while rainfall accompanied by wind helps initiate the blight phase. The purpose of this study was to evaluate potential new fungicides for disease control. Some treatments of Aliette and Fluazinam as well as Ridomil tended to reduce the incidence of disease in this trial. However, the high variability in disease incidence among the replicates of each treatment prevented the demonstration of statistically significant differences in this study. We hope to repeat this trial next year and achieve more definite results.
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Vanhoestenberghe, A. "Cross-talk in nerve root stimulator implants." Thesis, University College London (University of London), 2008. http://discovery.ucl.ac.uk/1504177/.
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Bramley, Helen. "Water flow in the roots of three crop species : the influence of root structure, aquaporin activity and waterlogging." University of Western Australia. School of Plant Biology, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0102.
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[Truncated abstract] The hydraulic properties of the roots of three crop species important to Western Australia were examined: wheat (Triticum aestivum), narrow-leafed lupin (Lupinus angustifolius) and yellow lupin (L. luteus). Generally, the hydraulic conductivity (Lpr) of root systems differs between species and can change in response to adverse conditions. To determine the significance of root anatomy and aquaporin activity on the pathway of water flow through roots, water flow was measured across cell membranes, individual roots and whole root systems. The combination of measurements identified that wheat and lupin roots have contrasting hydraulic properties. Wheat roots absorb water preferentially in the apical region, whereas lupin roots appear to absorb water more evenly along the entire root length. Lupin roots have a greater axial hydraulic conductance than wheat, due to more abundant xylem vessels and axial conductance increases with root length, in conjunction with xylem vessel development. However, water flow through the radial pathway is the limiting factor in whole root hydraulic conductance, in all species. Modelling and the inhibition of aquaporin activity with mercuric chloride demonstrated that radial water flow in wheat roots occurs by a combination of the cell-to-cell and apoplastic pathways, but in lupins, water flow appears to be predominantly apoplastic. Despite the presence of aquaporins in root cell membranes of all species, their role in regulating bulk water flow across roots is not clear in lupins, because of the significance of the apoplastic pathway ... After draining the chambers, the root systems of yellow lupin resumed growth, but there was no subsequent recovery in narrow-leafed lupin root systems. The growth and survival strategies of wheat and lupin root systems are disparate. Wheat root systems are comprised of numerous fine, highly branched, individual roots that extract water near the root tips and have the ability to regulate flow. These attributes may be advantageous in non-uniform or variable environments. Moreover, the ability of wheat roots to regulate flow may not only support survival during waterlogging, but also enhance recovery. In comparison, lupin root systems are designed like conduits, for the rapid uptake and transport of water when conditions are favourable. However, their thick taproots and lack of regulation of water transport or anatomical changes make them unsuitable for very wet soils.
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Hector, D. J. "Capture of soil water by crop root systems." Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378493.
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Brancalião, Sandro Roberto 1974. "Alterações de propriedades físicas e químicas e das frações húmicas de um nitossolo vermelho na sucessão milheto-soja em semeadura direta /." Botucatu : [s.n.], 2005. http://hdl.handle.net/11449/99969.
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Orientador: Maria Helena MoraesBanca: Sérgio Lázaro de Lima
Banca: Leandro Borges Lemos
Banca: Isabella Clerici de Maria
Banca: Antonio Costa
Resumo: O experimento, conduzido em Nitossolo Vermelho distroférrico, na Fazenda Experimental Lageado-FCA-UNESP-Botucatu, , teve por objetivo estudar no sistema de semeadura direta as prováveis alterações das propriedades físicas e químicas e das frações húmicas do solo, através da utilização da cultura do milheto em pré-safra a cultura da soja, em três épocas de semeadura e sob cinco manejos da fitomassa. O delineamento experimental foi o de blocos casualizados, com esquema de parcelas subdivididas, com quatro repetições. As parcelas foram representadas por três épocas de semeadura da cultura do milheto (E1, E2 e E3). As subparcelas foram representadas por manejos da ceifa da fitomassa, sendo: Manejo 1 (M1) - ceifa a cada florescimento e retirada da fitomassa; manejo 2 (M2) - ceifa a cada florescimento e permanência da fitomassa; manejo 3 (M3) - ceifa no florescimento e retirada da fitomassa; manejo 4 (M4) - ceifa no florescimento e permanência da fitomassa e manejo 5 (M5) - livre crescimento. Foram coletadas amostras de solo com estrutura deformada e indeformada para a realização das análises físicas e químicas. Tanto para a análise física quanto para a química, as mesmas profundidades foram amostradas: 0-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,40 m. Para o fracionamento químico da matéria orgânica, amostrou-se de 0-0,05 e 0,05-0,10 m. Em relação 2 as culturas avaliou-se a altura de plantas e a produtividade da soja e para o milheto, o seu sistema radicular, a quantidade de massa seca produzida pela parte aérea e a porcentagem de fitomassa em cobertura deixada sobre o solo. A produtividade de massa de matéria seca foi maior na primeira época de semeadura, excetuando-se o M3 para a segunda época e do M2 para a terceira época de semeadura. A segunda época de semeadura proporcionou maior fitomassa em cobertura... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This work was carried out at Lageado Experimental Station' FCA' Unesp' Botucatu, from October 2001 until April 2004, consisting in a millet' soybean succession, in a no-tillage system, at three sowing, and the aim was evaluate the physicals and chemicals and humics fractions of a "Nitossolo Vermelho Distroférrico". The experimental design used was randomized blocks, in a split-plot schedule with four replications, having the sowing (S1, S2, S3) as parcel and harvest handling as subparcel. Where the harvest handling were 1 (H1)' harvest each blooming and covering withdrawal; 2 (H2)' harvest each blooming and covering permanency; 3 (H3)' only in the first harvest on blooming and covering withdrawal; H4 - only in the first harvest on blooming and covering permanency, and H5 'free growing, with no harvest. Disturbed and undisturbed samples were collected from four soil layers (0-0,05, 0,05-0,10 and 0,10-0,20 m) to evaluate the physical and chemical properties. The physical parameters measured were: bulk density, total porosity, macroporosity, microporosity, total clay, disperse clay, floculation degree, aggregation stability (dry sieving) and penetration resistance (Compact Test); the chemicals was: pH, organic mater, exchangele basis (Ca, Mg, K), cationic exchangeable capacity (CEC) and the quantification of the humic fractions (C-AH, C-AF and C-HU) All the parameters were performed on Department of Natural Research's (Soil Science-FCA), in different depths 0-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,40 m. About the humic fractions were analyseds only 0-0,05 e 0,05-0,10 m. The pearl millet matter drought mass productivity decreased in the order S1 > S2 >S3. The soil cover provided by fitomassa of milheto was larger in the S2 > S2 and S3 and in the H4 (with only fitomassa cut and permanence)... (Complete abstract, click eletronic address below)
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Namaganda, Josephine Mary. "Nematode parasites of banana-root crop systems in Uganda." Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320191.
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Coimbra, Tomás Sassetti. "Mandioca. A cultura, a sua análise económica e a respectiva cadeia produtiva no Brasil." Master's thesis, ISA, 2014. http://hdl.handle.net/10400.5/6789.
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Mestrado em Agronomia Tropical e Desenvolvimento sustentável - Instituto Superior de AgronomiaCassava (Manihot esculenta Crantz) is a plant cultivated in the broad majority of tropical countries: genetic studies report its origin as from the amazonic basin from Brasil. This crop, used mainly as a food of great presence in the daily diet of the tropic populations, especially those of low income, has several applications such as its use in animal feeding as well as in the industries of food, textile, and energetic; predictions look to a future of growing importance of this crop in the exportation domain. This work first shows a characterization of cassava crop in the agronomic area, to afterwards, build the current context and the economic tendency of the past 20 years at Brasil and world levels. In this scope, the productive chain of starch in the center-south region of Brasil is characterized, highlighting the respective opportunities and limitations. At a world level, cassava is in rise, close to other large scale crops, having had an evolution superior to that of sweet-potato, a equally important tubercle. In Brasil, this crop is economically stagnated, due to many factors, here presented and discussed. In relation to the market of derivatives, as are starch and chips, it is dependent of Chinese demand, to supply their program of biofuels. These and other characteristics of the market and production of cassava will be referred in the present work so as to this important root can become better known, stated by some specialists as "a present from God".
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Makatchev, Maxim. "Cross-Cultural Believability of Robot Characters." Research Showcase @ CMU, 2013. http://repository.cmu.edu/dissertations/222.
Full textAbstract:
Believability of characters is an objective in literature, theater, animation, film, and other media. Virtual characters, believable as sharing their ethnic background with users, improve their perception of the character and, sometimes, even their task performance. Social scientists refer to this phenomenon as homophily—humans tend to associate and bond with similar others. Homophily based on ethnic similarity between humans and robots, however, has not previously been tested, in part due to the difficulties of endowing a robot with ethnicity. We tackle this task by attempting to avoid blatant labels of ethnicity such as clothing, accent, or ethnic appearance (although we control for the latter), and instead aim at evoking ethnicity via more subtle verbal and nonverbal behaviors.
Until now, when designing ethnically-specific virtual agents, their behaviors have been typically borrowed from anthropological studies and cultural models. Other approaches collect corpora of human interactions in target contexts and select maximally distinctive behaviors for further implementation on a virtual character. In this thesis, we argue that both behaviors that signal differences between an anthropologist and the target ethnicity (rich points), as well as maximally distinctive behaviors between target ethnicities, may vary on their ability to evoke ethnic attribution. We address this discrepancy by performing an additional evaluation of the candidate behaviors on their salience as ethnic cues via online crowdsourcing. The most salient ethnic cues are then implemented on the robot for a study with colocated participants.
This methodology has allowed us to design robot characters that elicit associations between the robot’s behaviors and ethnic attributions of the characters as native speakers of American English, or native speakers of Arabic speaking English as a foreign language, by members of both of these ethnic communities. Although we did not find evidence of ethnic homophily, we believe that the suggested pathway can be used to create robot characters with a higher degree of perceived similarity, and better chances of evoking homophily effect.