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1
Arpiwi, Ni Luh. "The application of novel methods for increasing the yield of small round seed potatoes (Solanum tuberosum L.) varieties Atlantic and Granola." University of Western Australia. School of Plant Biology, 2004. http://theses.library.uwa.edu.au/adt-WU2004.0020.
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Potato (Solanum tuberosum L.) varieties Atlantic and Granola are widely grown in Indonesia. The optimal method of cultivation in the tropics, due to the susceptibility of cut seed for disease, is by small (20 to 55 g) whole seed potatoes. However, the variety Atlantic produces mostly large tubers, which are not suitable for planting as whole seeds. Although Granola produces a reasonable proportion of small tubers it still produces a few in the larger size grades and there is no fresh market in Western Australia for the larger tubers for this variety. The aim of this study was to develop methods to be used in Western Australia that improve the yield of small seed potatoes for export to Indonesia. The influence of seed-potato storage duration (at 4°C) on subsequent stem growth was assessed after 30 days growth in a glasshouse (22°C/18°C, day⁄night). Seed potato storage for 22-28 (Atlantic) and 24-30 (Granola) weeks resulted in development of higher numbers of stems. A series of field experiment were designed to increase yield of small tubers. Apical sprout removal in Granola, but not Atlantic, increased the number of stems (by 27%), yield of 20-55 g potato (by 32%) and total yield (by 17%). Application of herbicide (paraquat + diquat) at low concentration during early tuber initiation decreased total yield in Atlantic (by 14%) and Granola (by 16%). Treating whole seed potatoes with carvone vapor two weeks before planting had no influence on stem or tuber number in both Atlantic and Granola but in Atlantic only, the total yield was reduced by 12%. Spraying plants with paclobutrazol during early tuber initiation inconsistently influenced tuber number and yield between the two varieties and two experiments. The influence of gibberellic acid (GA3) on stem number, total tuber number, yield of 20-55 g tubers and total yield was investigated by dipping seed pieces in a GA3 solution (20 mg⁄L) two days prior to planting. In Atlantic, GA3 treatment increased stem number (by 147%), total tuber number (by 75%) and yield of 20-55 g tubers (by 330%) without influencing total yield. In Granola, GA3 treatment increased stem number (by 50%), total tuber number (by 15%), yield of 20-55 g tubers (by 21%) and total yield (by 10%) The influence of gibberellic acid application (20 mg⁄L) to seed pieces before planting increased the number of small tubers through increased stem number. The shift toward a greater proportion of small tubers, without reducing total yield, had a greater influence in Atlantic than that in Granola. Treatment of GA3 and paclobutrazol together decreased total yield compared to that of GA3 alone
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Lucas, Carlos Krus Galvão. "Biogas production from potato peel waste." Master's thesis, Faculdade de Ciências e Tecnologia, 2014. http://hdl.handle.net/10362/12337.
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Hansford, Rachael J. "Effect of AM colonization on growth and yield in potato." Thesis, University of Aberdeen, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400721.
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This thesis aims to investigate the effect AM fungal inoculation and subsequent colonisation on the growth and tuber yield of potato. Different AM fungal inocula used produced different responses. Some fungal inocula did not colonise potato roots at all, even in suitable growth substrates (i.e. Glomus fasiculatum). It was observed that Glomus mosseae and Vaminoc Tâ formed the best associations with potato. However, the viability of inocula is a major concern for their commercial use. Phosphate had a significant effect on the growth of potato and AM formation. Plants grown in low phosphate were smaller in size and produced lower numbers of market sized tubers. Mycorrhizal formation was promoted at low P soil concentrations. Mycorrhizal plants grown at low P had increased yields of market sized tubers and tuber weights compared to the NM plants. This was mainly due to improved P nutrition and resulted in a tuber yield comparable to that produced by plants grown in high P. Increasing soil P concentrations decreased the level of AM formation. If mycorrhizal plants were given high P or grown at a low light intensity then no beneficial effects of colonisation were seen. Plants grown at low light intensities could not cope with the increased below ground demand of tubers and AM and this resulted in a decrease in the shoot C concentration. Early tuber removal decreased C-assimilation, increased subsequent tuber number and decreased the level of AM formation. This indicated that potato plants need to maintain a high photosynthetic rate in order to maintain an AM association. A decrease in C-assimilation caused a decrease in AM formation. The formation of AM in different potato cultivars was investigated. It was shown that different cultivars had varying responses to AM fungal inoculation. Those cultivars that had low disease resistance to microbial pathogens had higher levels of AM colonisation. Correlation analysis showed that there was an inverse relationship between disease resistance, and AM colonisation, irrespective of the growth of the potato. This indicated that breeding for disease resistance may have bred against the formation of AM in potato.
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Hogge, Murray Charles. "Effects of site, season and husbandry on yield and processing quality of the potato variety Pentland Dell." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.330034.
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Al-Farhan, H. N. "The effects of plant growth substances on the yield of potatoes." Thesis, Bangor University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234517.
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Soenarto. "Morphological components of yield in sweet potato (Ipomoea batatas (L.) Lam.)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ61177.pdf.
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Carrillo, Salazar Jose Alfredo. "An examination of the prediction of yield from two potato models." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342033.
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Ibrahim, Razi. "Predicting Potato Yield Loss Due to Metribuzin Sensitivity in North Dakota." Thesis, North Dakota State University, 2018. https://hdl.handle.net/10365/28860.
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A linear-log model to predict yield loss due to metribuzin injury was established by Love et. al. in 1993. Two experiments were conducted in 2016 and 2017 to evaluate and improve this model for application in North Dakota (ND). Metribuzin was applied (1.12 a.i./ha) when potato plants were 20-30 cm tall at Inkster, ND. The model did not accurately predict yield loss in 2016 but performed better in 2017. Foliar injury was more correlated with yield reduction than relative plant height. Results also indicated that new models that used foliar injury at 21 days after treatment (DAT) data and at 7 DAT data, most accurately predicted total yield loss and marketable yield loss, respectively. The new model performed similar to the previous model, but unlike previous model it can predict yield loss very early in growing season (21 DAT).USDA Specialty Block Grant Program
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Bunyolo, A. M. "Effects of fertilizer nitrogen and water supply on growth and yield of the potato crops." Thesis, University of Reading, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379220.
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Mohabir, G. "Biochemical investigations of yield-limitations in potatoes (Solanum tuberosum L.) under warm tropical conditions." Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380838.
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An, Le Van. "Sweet potato leaves for growing pigs : biomass yield, digestion and nutritive value /." Uppsala : Dept. of Animal Nutrition and Management, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a470.pdf.
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Palumbo, J. C. "Impact of Sweet Potato Whitefly Infestation on Yield and Quality of Cantaloupe." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/221467.
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A range of population levels of sweet potato whitefly, Bemisia tabaci Gennadius was evaluated in three field experiments allowing measurement of the effect of whitefly numbers on melon quality and yield. An increase in total numbers of immature whitefly was associated with significant declines in harvested melon weight, a decline in number of boxes harvested, a decrease in fruit size, a decrease in percent sugars, and an increase in sooty mold. Regression analysis of individual whitefly life stages with yield parameters indicated that adult number was a more precise parameter and higher R2 values were obtained with increased range of whitefly population densities. Adults were sampled at the third leaf node in both locations. Nymph samples were taken at varying nodes from the base of the plant. Estimates of the mean adult whitefly density resulting in 5% and 15 % dollar yield loss were 3 and 10 adults per leaf Estimates of the mean total nymph density resulting in 5% and 15% dollar yield loss 0.5 and 2 (AZ) nymphs per cm² of leaf area, respectively.
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Ajuoga, Okeyo James. "Evaluation of yield and quality of five potato cultivars grown in Southwest Virginia." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-12042009-020021/.
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Chand, Shyam Prakash. "Effect of time of planting of traditional potato varieties on yield of intercropped potato and maize in the hills of Nepal." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243282.
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Fowler, James H. "Effect of plant arrangement and density on growth development and yield of two potato varieties." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257946.
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Dresow, Jana Franziska [Verfasser]. "Optimization of organic potato production : influence of agronomical measures on yield and quality of table potatoes and processing potatoes / Jana Franziska Dresow." Kassel : Universitätsbibliothek Kassel, 2013. http://d-nb.info/1046188526/34.
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Plotkin, Jeremy Barker. "The Effects of Green Manure Rotation Crops on Soils and Potato Yield and Quality." Fogler Library, University of Maine, 2000. http://www.library.umaine.edu/theses/pdf/PlotkinJB2000.pdf.
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White, Marcia Diane 1950. "POTATO SEED PIECE CARBAMATE PROTECTANT EFFECTS ON SPROUTING, GROWTH AND YIELD (BENOMYL, MANEB, MANCOZEB)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276366.
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Worthington, Christine Maria. "Timing of climatic factors that may influence potato yield, quality, and potential nitrogen losses in a northeast Florida seepage-irrigated potato production system." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0015765.
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Santos, Joana. "Effects of fertility management and natural foliar sprays on late blight (Phytophthora infestans), potato yield and tuber quality in organic potato production systems." Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433142.
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Okeyo, James Ajuoga. "Effects of topping, stem density, and stage of vine cutting on canopy growth and tuber yield yield of potato (Solanum tuberosum L.)." Diss., Virginia Tech, 1995. http://hdl.handle.net/10919/39156.
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Haverkort, A. J. "Relationships between intercepted radiation and yield of potato crops under tropical highland conditions of Central Africa." Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370132.
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Upadhaya, Arjun. "Plant-Parasitic Nematodes in Field Pea and Potato and their Effect on Plant Growth and Yield." Thesis, North Dakota State University, 2018. https://hdl.handle.net/10365/28875.
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In this study, surveys were conducted in pea and potato fields in North Dakota and Central Minnesota to investigate the incidence and abundance of plant-parasitic nematodes in these fields. Moreover, the effect of the pin nematode, Paratylenchus nanus, on plant growth and yield of six field pea cultivars was determined under greenhouse conditions. Similarly, the influence of lesion nematode, Pratylenchus penetrans, and wilt fungi, Fusarium oxysporum alone and together on growth and yield of potato cultivar ‘Red Norland’, was evaluated in microplots under field conditions. The results indicate Paratylenchus spp. and Pratylenchus spp. are the most frequent nematodes, respectively, in pea and potato fields. Pin nematodes reproduced on field pea cultivars and caused up to 37% reduction in plant height and 40% reduction in yield. Additionally, both P. penetrans and F. oxysporum alone, and together had significant negative effect on growth and yield of potato.
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Sarries, Juan Miguel. "Effects of physiological age of potato seed on plant development and yield in dual cropping systems in Uruguay." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=185659.
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In N. Uruguay two potato (Solanum tuberosum L.) crops are grown per year, one in the fall and the other in spring. In each season physiologically young seed tubers are planted, resulting in relatively slow crop emergence and low yields. The aim of the current research was to determine the effects of physiological ageing of seed tubers on the dynamics of canopy growth, radiation interception and radiation use efficiency (RUE) of crops in the short seasons of Uruguay and to identify opportunities for increasing yield. Experiments were conducted on cv Chieftain over three years from 2000 to 2002. Prior to planting seed was stored at different controlled temperatures to generate physiological ages (measured in thermal time) ranging from 0 (the youngest) to 1200 oC days (the oldest). Ageing led to earlier crop emergence (3-9 days depending on the year), but its potential benefits on radiation interception, dry matter production and yield were negated by an earlier canopy senescence and often smaller canopy size. There was no consistent effect of ageing on RUE although the harvest index was increased. Leaf tagging showed that leaf appearance and senescence was advanced by ageing and the lifespan of individual leaves was reduced. Leaf lifespan did not appear to be related to the sink demand by tubers for assimilate, because removal of tubers at the start of bulking had no effect on lifespan. Maintaining canopy structure during senescence led to a small increase in yield. Although physiological ageing did not result in a consistent increase in yield in either season, use of older seed may provide an insurance against the risk of adverse weather conditions late in the season terminating tuber bulking prematurely.
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Sebastiani-Kuoko, Stephen. "Potato production systems in the northern highlands of Tanzania : a study of the yield potential and associated constraints." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242125.
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Mukminah, Faridatul. "Growth, photosynthetic capacity and yield potential of sweet potato (Ipomoea batatas L. (Lam.)) as affected by irrigation levels /." Göttingen : Cuvillier, 2001. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009595464&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Juntharathep, Pintip. "Effect of varietal resistance, copper fungicides and agronomic practices on late blight (Phytophthora infestans), potato yield and tuber quality characteristics and soil Cu levels in organic potato production systems." Thesis, University of Newcastle Upon Tyne, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413019.
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Demagante, Antonia L. "Potato production in the hot lowland tropics : effects of water stress on the growth and yield of diverse genotypes." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293228.
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Ghosh, Upasana. "Irrigated Potato (Solanum Tuberosum L.) Yield, Quality Response and Nitrogen Losses as Influenced by Nitrogen Fertilizer Management and Cultivars." Diss., North Dakota State University, 2017. https://hdl.handle.net/10365/26492.
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Field studies were conducted in 2015 and 2016 growing season at Northern Plains Potato Growers? Association Irrigation site near Inkster, ND to evaluate the effectiveness of enhanced efficiency fertilizers (EEFs) in maintaining yield, quality and reducing environmental nitrogen (N) losses in irrigated potatoes (Solanum tuberosum). Two types of EEFs i.e. SuperU (urea with urease and nitrification inhibitor) and ESN (polymer coated urea); grower?s standard fertilization and unamended urea were applied in three late-sown russet potato cultivars. Our findings suggested that yield responses vary widely with respect to years, length of growing season and cultivar type. Among EEFs, ESN consistently maintained yield compared to conventional fertilization practices. In shorter growing season (114 days), no yield benefit over N rate of 225 kg ha-1 was obtained with higher N rates (280 kg N ha-1) and different N sources in all three cultivars. Determinate cultivars can be a better choice to get good yield with lower N rate in shorter growing seasons. Both of the EEFs significantly reduced N losses through ammonia (NH3) volatilization and nitrous oxide (N2O) emission compared to unamended urea and grower?s standard fertilization practice. SuperU did not reduce residual soil nitrate (NO3-) compared to unamended urea while ESN reduced residual soil NO3-. Overall, ESN or polymer coated urea (PCU) is a promising choice for reducing N losses from irrigated potatoes. Plant N status assessment is important for yield prediction. Despite of being time consuming, total N concentration in petioles gave the better estimate of crop N status compared to standard petiole NO3-N concentrations. For early season quick N status measurement, ground based active optical sensors should be used in a cultivar specific way. Nitrogen fertilization recommendation for irrigated potatoes in North Dakota should be recalibrated considering length of growing season and cultivar type.North Dakota (USDA) Specialty Crop Block Grant Program
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Abolgasem, Tounis Maoloud Mohmed. "Effect of variety, fertilisation, rotation, crop protection and growing season on yield and nutritional quality of potato (Solanum tuberosum L.)." Thesis, University of Newcastle upon Tyne, 2014. http://hdl.handle.net/10443/2551.
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Potatoes (Solanum tuberosum L.) are the most important food crop in the world after rice and wheat. Potato tubers contain many types of essential nutrients. They contain high concentrations of carbohydrates and also vitamins, minerals and protein. They also contain toxic compounds called glycoalkaloids. Potato is classed as a protective vegetable because of its high vitamin C content. The objectives of this study were to determine the effects of different fertiliser types (composted cattle manure, mineral NPK fertiliser), pre-crop (beans, barley) crop protection protocols (organic, conventional) and growing season on the nutritional quality of vitamin C, glycoalkaloids and minerals and yield of different varieties of potato (Sante, Sarpo Mira, Nicola, Fontane, Agria and Cara). Field experiments were carried out during the 2010 and 2011 growing seasons at Nafferton Farm (Newcastle University). The experiment was a split split split plot-design. The main plot was crop rotation, the sub-plot was crop protection, the sub-sub plot was fertility management and sub-sub-sub plot was variety. The vitamin C content was determined by two different methods of analyses; colorimetric titration and high- performance liquid chromatography (HPLC). Mineral content was assessed by the Dumas combustion method at Sabanci University, Turkey. Total glycoalkaloids were determined according to the AOAC method 997. 13. A significant effect of fertilisation was detected for potato yield for both of years. In plots treated with NPK fertilisers, higher yield, compared to compost was obtained for both seasons. In addition conventional crop protection increased yield in both years. Pre-crop significantly affected yield in both years, with higher yields being recorded after beans than barley in 2010 while, a pre-crop of barley resulted in the significantly higher yield than beans in 2011. However, no significant difference between varieties was detected. Also, no significant interactions were detected for tuber yield in 2010. However a significant 2-way interaction between crop protection and pre-crop was observed in 2011, with a pre-crop of beans resulting in the highest yields under conventional crop protection, while a pre-crop of barley resulted in the significantly higher yield under organic crop protection systems. Results of the second growing season (2011) were based on the NUE potato experiment and showed that there was significant difference (P < 0.05) in yield between varieties, fertilisation iii and crop protection. A significant interaction between fertilisation and variety was detected for the yield. There was a significant effect of variety on tuber vitamin C content (P < 0.001), in 2010 and 2011. The concentrations were higher in Sante than Sarpo Mira. There were no significant influences of other treatments (fertility, rotation, crop protection). However, a 2-way interaction between fertilisation and variety was detected in 2011. In 2011 there was a significant effect of varieties on vitamin C content, but no significant effect of fertility and crop protection treatments. However, a significant interactions between fertility, variety and crop protection treatments was detected but only for the titration analysis for vitamin C content. There were no significant effects (P > 0.05) of fertilisation, pre-crop and crop protection on glycoalkaloid concentrations. However, a significant 3-way interaction between fertilisation, variety and rotation was detected for alpha solanine in 2011. A significant 3-way interaction between crop protection, fertilisation and variety was detected for alpha chaconine in 2010. In 2010 the mineral content (N, P, K, Na and Ca) of potatoes was significantly affected by fertilisation treatments. N, P and Ca contents were significantly increased by NPK application while the K and Na contents were significantly increased by compost application. In 2011 Ca contents were affected by fertilisation treatments only. Effects of variety, rotation and crop protection and interactions between factors were also detected for macro mineral contents. However, in 2011 no effect of pre-crop on tuber macronutrient concentration was detected. There was a significant difference in micronutrient concentration between variety, fertilisation and crop protection. No significant effect of rotations was detected for micronutrient concentrations in both of seasons. In conclusion, in both years, 2010 and 2011, variety significantly affected vitamin C content of potato tubers, but there were no significant effects of fertility, pre-crop and crop protection treatments irrespective of the analytical method (titration and HPLC) analysis. Sante tubers contained about 20% more vitamin C than Sarpo Mira. Therefore, it appears that variety choice is a reliable means of manipulating vitamin C as a component of tuber quality compared with other agronomic treatments. In addition, mineral content was also affected by treatments (fertility, variety, rotation and crop protection) and was highly variable. iv For the two years, similar results were obtained in alpha solanine and alpha chaconine content. Significant interactions between rotation, fertilisation and variety were only detected on alpha solanine content during 2011. Also, significant interactions between variety, fertility and crop protection were observed on alpha chaconine content during 2010. The 2010 and 2011 growing seasons appeared to have a significant effect on alpha solanine, macro minerals and micro minerals but did not appear to affect yield, vitamin C and alpha chaconine contents.
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Satchithanantham, Sanjayan. "Water management effects on potato production and the environment." American Society of Agricultural and Biological Engineers (ASABE), 2012. http://hdl.handle.net/1993/22279.
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Potatoes (Solanum tuberosum) were grown in a fine sandy loam soil in southern Manitoba in a three-year field study comparing four water management treatments: No Drainage with No Irrigation (NDNI), No Drainage with Overhead Irrigation (NDIR), Free Drainage with Overhead Irrigation (FDIR), and Controlled Drainage with Subirrigation (CDSI). The objectives of the study were (i) to evaluate the effect of the four treatments on yield and quality of potatoes, (ii) to evaluate the effect of water management on the environment, (iii) to estimate the shallow groundwater contribution to potato water requirement, and (iv) to simulate the shallow groundwater hydrology using the DRAINMOD and HYDRUS 1-D model. Subsurface drains were installed at 0.9 m depth and at spacings of 15 m (FDIR) and 8 m (CDSI). Subirrigation was done by pumping water back into the tiles through the drainage control structures. Overhead irrigation was carried out using a travelling gun. Water table depth, soil water content, drainage outflow, nutrient concentration in drainage water, irrigation rate, weather variables, potato yield and quality parameters, and biomass were measured. Compared to the NDNI treatment, the potato yield increase in the other treatments ranged between 15-32% in 2011 and 2-14% in 2012. In 2011, potato yield from FDIR was higher than CDSI (p = 0.011) and NDNI (p = 0.001), and yield from NDIR was higher than NDNI (p = 0.034). In 2012, potato yield was higher in FDIR in comparison to NDNI (p = 0.021). In 2012, the NDIR gave higher dark ends (p = 0.008) compared to other treatments. Under dry conditions, up to 92% of the potato crop water demand could be met by shallow groundwater contribution. Compared to free drainage, controlled drainage was able to lower the nitrate export by 98% (p = 0.033) in 2010 and by 67% (p = 0.076) in 2011, and the phosphate export decreased by 94% (p = 0.0117) in 2010. A major part of the drainage flow and nutrient export took place between April and June in southern Manitoba. DRAINMOD was able to accurately predict the shallow groundwater hydrology for this particular research site.
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NDAYISENGA, VALENCE. "APPROPRIATE FOOD PRODUCTION THROUGH INCREASING CROP YIELD AND INTRODUCING NEW CROPS IN THE DEMOCRATIC REPUBLIC OF THE CONGO." Doctoral thesis, Università Cattolica del Sacro Cuore, 2018. http://hdl.handle.net/10280/53793.
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La mancanza di una buona dieta ben bilanciata nutrizionalmente, porta al persistente sottosviluppo, in particolare per la capacità fisica e intellettuale delle persone e ha un impatto negativo sullo sviluppo del Paese. La presente tesi di dottorato mirava a valutare le strategie per produrre un cibo appropriato sufficiente, sicuro e sostenibile attraverso la sperimentazione di diverse tecniche di coltivazione e cultivar locali di manioca per identificare quali tecniche e cultivar sono più performanti per aumentare la resa. Dall’altra parte, al fine di contribuire alla diversificazione della produzione del cibo e al miglioramento del piatto tradizionale congolese costituita da più di 80% di carboidrati in particolare la manioca, studi su nuove colture riconosciute contenere dei buoni livelli in proteine, vitamine e minerali come Patata dolce a polpa arancione (Ipomoea batatas) riconosciuta essere ricca soprattutto in provitamina A e quinoa (Chenopodium quinoa Willd.) riconosciuta in particolare per il suo buon contenuto di aminoacidi ben bilanciato sono state condotte. Come risultato, tra tre tecniche di coltivazione (Ridge, Mound e Flat) per la produzione di manioca e 5 cultivar locali di manioca (Dunda, Kakuanga, Kasongoy, Kasonie, Ngoymuamba) valutati, la coltivazione su Ridge e il culltivar Ngoymuamba hanno dato il risultato più alto (19,2 Mg ha-1 di tuberi freschi), mentre Dunda è stata la cultivar che ha prodotto molto meno (6,8 Mg ha-1 di tuberi freschi). Le cultivar di patata dolce a polpa arancione studiati, hanno dimostrato che il contenuto in β-carotene è ragionevolmente alto perché 87 g di tuberi fresche sono sufficienti per coprire la dose giornaliera raccomandata in vitamina A per gli adulti. Per quinoa, tre cultivar (Pasankalla, Puno, Titicaca) hanno dimostrato di produrre una resa considerevole in quanto la produzione in granella è stata rispettivamente di 2,2 Mg ha-1; 1,9 Mg ha-1; 1,3 Mg ha-1 per Titicaca, Pasankalla e Puno.The lack of a good diet well balanced nutritionally, leads to the persistent underdevelopment, particularly for the physical and intellectual capacity of the people and impacts negatively on the development of the country. The present doctoral thesis aimed to assess strategies to produce an appropriate food sufficient, safe and sustainable through experimenting different cultivating techniques and local cultivars of cassava for identifying which techniques and cultivars are more performant to increase yield. On the other hand, in order to contribute to the diversification of food production and improvement of the traditional Congolese diet constituted by more than 80% of carbohydrates particularly cassava, new crops recognized to have a better content in protein, minerals, and vitamins such as Orange-Fleshed Sweet Potato (Ipomoea batatas) recognized to be rich especially in provitamin A and quinoa (Chenopodium quinoa Willd.) recognized particularly for its well-balanced amino acids content were studied. As results, among three Planting methods (Ridge, Mound, and Flat) for producing cassava and 5 local cultivars of cassava (Dunda, Kakuanga, Kasongoy, Kasonie, Ngoymuamba) assessed, ridge and culltivar Ngoymuamba resulted to give the highest yield (19.2 Mg ha-1 in fresh roots), while Dunda was the cultivar which produced the lowest yield (6.8 Mg ha-1 in fresh roots). The Orange-Fleshed Sweet Potato cultivars studied showed that its content in β-carotene is reasonably high as 87 g per day can cover the whole daily allowances of vitamin A in adults’ people. On the quinoa side, three cultivars (Pasankalla, Puno, Titicaca) demonstrated to produce considerable yield as the production in grain was 2.2 Mg ha-1, 1.9 Mg ha-1, 1.3 Mg ha-1, respectively for Titicaca, Pasankalla and Puno.
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Tsegaw, Tekalign. "Response of potato to paclobutrazol and manipulation of reproductive growth under tropical conditions." Thesis, Pretoria : [s.n], 2005. http://upetd.up.ac.za/thesis/available/etd-02082006-112218.
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Schönhals, Elske Maria [Verfasser], and Christiane [Akademischer Betreuer] Gebhardt. "Identifying novel diagnostic SNP markers for potato (Solanum tuberosum L.) tuber starch and yield by association mapping / Elske Maria Schönhals. Gutachter: Christiane Gebhardt." Köln : Universitäts- und Stadtbibliothek Köln, 2014. http://d-nb.info/1054420394/34.
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Valikonis, Vytautas. "Ekolist trąšų panaudojimo technologijų įvertinimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2009~D_20090608_124233-43257.
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Tyrimai vykdyti 2007-2008 metais Lietuvos žemės ūkio universiteto Bandymų stotyje karbonatingame giliau glėjiškame išplautžemyje (IDg 4-k), vidutinio sunkumo priemolyje ant molio. Tirtos dvi EKOLIST trąšų panaudojimo technologijos.
Bulvių pasėlyje EKOLIST panaudojimo technologijoje per lapus buvo tręšta 2 kartus: 1) bulvėms sudygus; 2) po 10-14 parų nuo pirmo purškimo. EKOLIST trąšų II panaudojimo technologijoje per lapus tręšta tris kartus: 1) bulvėms sudygus; 2) po 10-14 dienų nuo pirmo purškimo; 3) po bulvių žydėjimo.
Vasarinių rapsų pasėlyje EKOLIST I panaudojimo technologijoje per lapus buvo tręšta 2 kartus: 1) 8-10 tikrųjų lapelių tarpsnyje; 2) butonizacijos tarpsnio pradžioje.
EKOLIST II panaudojimo technologijoje per lapus buvo tręšta 3 kartus: 1) 8-10 tikrųjų lapelių tarpsnyje; 2) po 7-10 dienų nuo pirmo purškimo; 3) butonizacijos tarpsnio pabaigoje.
Tyrimais nustatyta, kad bulves papildomai per lapus Ekolist trąšomis tikslinga tręšti tris kartus (panaudoti EKOLIST II technologiją). Palyginus su netręštais laukeliais, prekinių bulvių derlius padidėjo 3,56 t ha-1 arba 11,3%. Ekolist trąšų įtakoje bulvių gumbuose sausųjų medžiagų, krakmolo ir bendrojo cukraus kiekiai nepakito, tačiau sumažėjo nitratų kiekis.
Vasarinius rapsus papildomai per lapus Ekolist trąšomis tikslinga tręšti du kartus (panaudoti EKOLIST I technologiją). Palyginus su netręštais laukeliais, vasarinių rapsų absoliučiai sausų sėklų derlius padidėjo 0,11 t ha-1 arba 5,5%, sėklų riebalingumas – 1... [toliau žr. visą tekstą]The experiments were carried out in the Experimental Station of Lithuanian University of Agriculture on the Calc(ar–Endohypogleyic Luvisol (LVg-n-w-cc) in 2007-2008. Granulometric composition of the soil was light or medium heavy loam on heavy loam clay. Two Ekolist fertilizers usement technologies were investigated. In I Ekolist usement technology on potato crop leaf-feed fertilizers were applied twice: 1) when potatoes were sprouting; 2) after 10 – 14 days from the first spraying. II Ekolist fertilizers usement technology on potato crop leaves spray fertilizers were applied in 3 times: 1) when potatoes were sprouting; 2) after 10 -14 days from the first spraying; 3) after potatoes flowering. In I usement Ekolist technology on spring rape crop leaf-feed fertilizers were applied twise: 1) at the 8 – 10 leaves stage; 2) at the stage of bud formation beginning. In II usement Ekolist technology leaves spray fertilizers were applied in 3 times: 1) at the 8 – 10 leaves stage; 2) after 7 -10 days from the first spraying; 3) at the stage of bud formation ending. The research date indicated that additional fertilization for potato was most effective, when fertilizers were applied in 3 times (II Ekolist technology). Compared with not fertilized fields, marketable potatoes yield increased 3,56 t ha-1 or 11,3%. Under the effect Ekolist fertilizers unchanged dry matter amount, starch amount, common sugar amount in the potatoes tubers, however decreased nitrate amount. Additional... [to full text]
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Vuk, Vujasinović. "Prinos i kvalitet mladog krompira u zavisnosti od agrotehničkih mera i agroekoloških uslova proizvodnje." Phd thesis, Univerzitet u Novom Sadu, Poljoprivredni fakultet u Novom Sadu, 2016. https://www.cris.uns.ac.rs/record.jsf?recordId=101166&source=NDLTD&language=en.
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Proizvodnja mladog krompira u Srbiji je značajna zbog obezbeđenja ove izuzetno cenjene i delikatesne namirnice u periodu od aprila do juna kada je u ponudi na tržištu malo drugog svežeg povrća. Osim toga cena mladog krompira je uglavnom visoka, pa je značaj i po osnovu profitabilnosti ove kulture velik.U periodu 2004-2006. godine ispitivan je efekat malčovanja polietilenskom folijom ineposrednog pokrivanja biljaka sa i bez noseće konstrukcije, kao i kombinacija ovih specifičnih agrotehničkih mera na ranostasnost, prinos i komponente prinosa i kvalitet mladog krompira kod ranih sorti Cleopatra i Riviera. U cilju rešavanja postavljenog zadatka sprovedeno je istraživanje, na lokalitetu južno bačkog okruga (Begeč), postavljen je dvofaktorijalni ogled po split plot planu u pet ponavljanja.Ispitivane agrotehničke mere i njihove kombinacije značajno su uticale na ranostasnost i prinos mladog krompira. Formiranje tržišnih krtola (krtole veće od 28 mm) bilo je za 10-15 dana ranije u odnosu na kontrolnu (nepokrivenu) varijantu. Najveći prinos u trogodišnjem istraživanju postignut je na varijanti agrotekstil+niski tunel (40,07 t/ha). U odnosu na kontrolnu varijantu, prinos je bio veći za 19% (u prvoj godini za 22%, drugoj za 16%, dok je u trećoj godini prinos bio veći za 18%).Najveći broj krtola mladog krompira, u trogodišnjem istraživanju, ostvaren je nakontrolnoj varijanti (9,43), stim što je udeo tržišnih krtola (krtole veće od 28 mm) na kontroli iznosio 89% naspram 95% ostvaren na pokrivenim varijantama. Riviera je ostvarila veći broj krtola po biljci u odnosu na Cleopatru.Ispitivane agrotehničke mere uticale su na povećanje mase krtola po biljci. Najveća masa krtola po biljci u trogodišnjem ogledu ostvaren je na tretmanima agrotekstil+niski tunel (853,17 g) i malčovanje+agrotekstil+niski tunel (850,17 g), dok je najmanja masa zabeležena na kontrolnoj varijanti (640 g). Sorta Riviera je ostvarila značajno veću masu krtola u odnosu na Cleopatru.Ispitivani tretmani su ostvarili veću prosečnu masu jedne krtole za 52% u odnosu nakontrolnu varijantu.Ispitivani tretmani značajno su uticali i na kvalitet mladog krompira; odnosno napovećanje sadržaja suve materije, skroba, vitamina C, celuloze i pepela u krtolama, a nasmanjenje sadržaja šećera i nitrata.Production of early potato in Republic of Serbia is important because it provides thishighly valued delicates food during the period from April to June, when there is low offer of otherfresh vegetables on the market. Besides, price of early potato is usually high so it is important asprofitable crop.During the period 2004-2006 effect of mulching with polyethylene foil and directcoverage of plants with agrotextile and low tunnel, as well as combinations of these specificagricultural measures on earliness, yield and yield components and quality of two early potatovarieties Cleopatra and Riviera was examined. In order to achieve given objective research wasconducted at the site in South Bačka District (Begeč), it set up the two-factorial experiment atsplit plot plan in five replications.The tested of agricultural measures and their combinations significantly influencedearliness and yield of early potato. The forming of market tubers (tubers larger than 28 mm) was10-15 days earlier than on the control variant (bare soil and uncover plants). The highest yield ofthe three-year study has been made on the variant combination of agrotextile and low tunnel(40,07 t/ha). Compared to the control variant, the yield was increased by 19% (in the first yearincrease of 22%, second year increase was 16%, while in the third year yield increase was 18%).The largest number of tubers of early potatoes, in three-year study, has been on thecontrol variant (9,43), but the share of market tubers (tubers larger than 28 mm) on the controlvariant was 89% versus 95% achieved in covered variants. Variety Riviera has achieved greaternumber of tubers per plant compared to variety Cleopatra.The tested agricultural measures affected mass increase of tubers per plant. Themaximum weight of tubers per plant in the three-year experiment was realized in the treatmentcombination of agrotextile and low tunnel (853,17 g) and combination of mulching, agrotextileand low tunnel (850,17 g), while the lowest mass was recorded in the control variant (640 g).Variety Riviera has achieved significantly higher tuber weight relative to Cleopatra.The tested treatments have also achieved a higher average weight of a tuber of 52%compared to the control variant.The tested treatments significantly influenced quality of early potato; i.e. the increase thecontent of dry matter, starch, vitamin C, cellulose and ash in the tubers and on reduction of sugarand nitrate content.
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De, Villiers André Jaco. "The influence of different calcium levels, irrigation methods and storage temperatures on the yield, quality and growth potential of G0 mini-tubers /." Link to the online version, 2007. http://hdl.handle.net/10019.1/2952.
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Mohamed, Nahla Abdel-Fattah Hemdan. "Irrigation systems." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2014. http://dx.doi.org/10.18452/16977.
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In der Wintersaison 2005-2006 wurde ein Split-Split Plot-Design Feldversuch mit drei Wiederholungen für jede Behandlung von Kartoffeln, als Indikatorpflanze, unter den ariden Bedingungen der Kharga Oasis in der Westlichen Wüste von Ägypten durchgeführt. Drei Bewässerungslevel (100 %, 80 %, und 60 % of ETc) mit Tröpfchenbewässerung, zwei Mulchvarianten (Zuckerrübenabfall ohne und mit 24 ton ha-1) und 4 Kompostraten (0, 12, 24, und 36 ton ha-1) wurden getestet. Generell und als Ergebnis einer Regressionsanalyse der Versuchsvarianten ohne Kompost war die beste Variante die Tröpfchenbewässerung bei 80% ETc unabhängig ob gemulcht oder nicht gemulcht wurde. Andererseits die Variante mit 36 t Kompost und mit 24 t Mulch ergab die besten Ergebnisse bei 60% of ETc sowohl beim Ertrag und den Ertragskomponenten, bei den hydrophysikalischen Eigenschaften, bei der Bodenwasserretention, beim Wasserverbrauch, bei den Pflanzenkoeffizienten, der Wassernutzungseffizienz, der Düngernutzungseffizienz sowie beim Nettogewinn. Wird die Rate der Kompostgabe aber auf 24 ton ha-1 reduziert, die höchsten Nettogewinne bei der lokalen Vermarktung als auch signifikant beim Kartoffelexport werden erreicht.Under the arid condition of Kharga Oasis in the Western Desert of Egypt, split-split plot design field experiment with three replications for each treatment using potato as an indicator plant was carried out during the winter season 2005-2006. Three irrigation levels of water regime (100 %, 80 %, and 60 % of ETc) using drip irrigation system, two treatments of soil covering (sugar cane wastes at the rate of 0 and 24 ton /ha) and compost rates (0, 12, 24, and 36 ton ha-1) were tested. In general and as a result of the triple interaction among the studied treatments, using drip irrigation either with soil mulching or not, 80 % of ETc as a water regime was the best. On the other hand, reducing drip irrigation water level at 60% of ETc in mulched soil that was treated with 36 ton ha-1 of compost recorded the highest values yield and yield components, soil hydrophysical properties, soil water retention, water consumption, crop coefficients, water economy water use efficiency, fertilizer use efficiency, net profit. But reducing the compost rate to 24 ton ha-1 attained the highest net profit for local potato consumption and achieved the best significant net profit for exportation.
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Modisane, Pulane Charity. "Yield and quality of potatoes as affected by calcium nutrition, temperature and humidity." Diss., Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-10022007-102327.
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Sivarajan, Saravanan. "Estimating Yield of Irragated Potatoes Using Aerial and Satellite Remote Sensing." DigitalCommons@USU, 2011. http://digitalcommons.usu.edu/etd/1033.
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Multispectral aerial and satellite remote sensing plays a major role in crop yield prediction due to its ability to detect crop growth conditions on spatial and temporal scales in a cost effective manner. Many empirical relationships have been established in the past between spectral vegetation indices and leaf area index, fractional ground cover, and crop growth rates for different crops through ground sampling. Remote sensing-based vegetation index (VI) yield models using airborne and satellite data have been developed only for grain crops like barley, corn, wheat, and sorghum. So it becomes important to validate and extend the VI-based model for tuber crops like potato, taking into account the most significant parameters that affect the final crop yield of these crops.
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Sivarajan, Saravanan. "Estimating Yield of Irrigated Potatoes Using Aerial and Satellite Remote Sensing." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1049.
Full textAbstract:
Multispectral aerial and satellite remote sensing plays a major role in crop yield prediction due to its ability to detect crop growth conditions on spatial and temporal scales in a cost effective manner. Many empirical relationships have been established in the past between spectral vegetation indices and leaf area index, fractional ground cover, and crop growth rates for different crops through ground sampling. Remote sensing-based vegetation index (VI) yield models using airborne and satellite data have been developed only for grain crops like barley, corn, wheat, and sorghum. So it becomes important to validate and extend the VI-based model for tuber crops like potato, taking into account the most significant parameters that affect the final crop yield of these crops.
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Kalifa, Ali. "Salt stress, and phosphorus absorption by potato plants cv. 'Russet Burbank'." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq29727.pdf.
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Hiles, Christopher D. "Defining in-season nitrogen needs for maximum economic yields and quality for Alturas and Premier Russet." Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Thesis/Spring2010/C_Hiles_042110.pdf.
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Thesis (M.S. in horticulture)--Washington State University, May 2010.Title from PDF title page (viewed on May 11, 2010). "Department of Horticulture and Landscape Architecture." Includes bibliographical references.
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Chipungahelo, Grace Mwaijande Samuel. "Intercropping sweet potato (Ipomoea batatas L. Lam.) cowpea (Vigna unguiculata L. Walp) and pineapple (Ananas comosus L. Merr.) under coconut (Cocos nucifera L.) in Tanzania." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299624.
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Seome, Daphney Gaafele. "Application of silicon to improve yield and quality of potatoes (Solanum Tuberrosum L.)." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/41024.
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The potato (Solanum tuberosum L.) crop serves as a staple food worldwide and is capable of
reducing the world’s food shortages because unlike cereals and other agricultural crops, it is less
affected by prices in the international markets. Research on alleviation of food crises suggested
root and tuber crops such as potatoes to be the solution to the problem of food shortage. The crop
is widely cultivated but is difficult to produce due to susceptibility to numerous pests and
pathogenic organisms, as well as abiotic stresses. To control these pests and diseases, strategies
to limit susceptibility to factors that interfere with the growth and development of plants, or
breeding new varieties that are able to withstand stresses are being researched. Recent studies
have shown that non essential nutrients such as Silicon (Si) are beneficial to plants in terms of
yield, protection from fungal diseases and improved uptake of phosphorus.
Since very little research has focused on the role of Si in improving potato production, three
glasshouse pot trials were conducted at the Hatfield Experimental farm and Department of Plant
Pathology glasshouses of the University of Pretoria to evaluate the effect of various soil
amendments on potato yield and quality. The effect of these soil amendments on pH was also
investigated as P-uptake and development of common scab in potatoes are pH dependent. The
soil amendments consisted of different silicon sources and an agricultural lime. The Si sources
were Calmasil slag (Middleburg) (30% Si- containing liming material), fly ash (50% Si nonliming
material), and Si fume/ash (99% Si non-liming material). Agricultural lime (CaCO3) was
included as a control.
The purpose of the first two trials was to identify the most promising silicon-containing source
for potato production, while the third trial evaluated the effect of this silicon source on soil pH
and potato tuber yield. In all three trials, agricultural lime was used as a control. Due to the high
demand for nutrients by the potato crop, other nutrient elements were added to the soil through
fertigation every 7 to 14 days, depending on the growth stage of the plants. Plants were irrigated
with distilled water when necessary to maintain an adequate moisture level i.e. moist but not too
wet. Weekly observations on growth parameters were made. To select the most promising soil
amendment, parameters such as leaf chlorophyll content, plant height, tuber number and mass
(Fwt), fresh and dry weight (top growth) and change in soil pH were analyzed. Slag treated
plants tended to produce tubers with higher mass and better appearance. In this study the highest
increase in soil pH was observed in soil mixed with slag, compared to all the other silicon
sources. Although there was no significant difference observed among treatments there was a
distinct difference in plant growth between trials when soil was amended with lime and slag.
Plants treated with slag tended to produce tubers that weigh more, whilst plants treated with lime grew taller and had the highest tuber number. There was a significant rise in soil pH from both
lime and slag, which might have in turn influenced vegetative and tuber growth.Dissertation (MInst(Agrar)--University of Pretoria, 2013.
gm2014
Plant Production and Soil Science
unrestricted
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Rosenfeld, Anton Benjamin. "Effects of nitrogen and soil conditions on growth, development and yield in potatoes." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624673.
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Hassan, M. A. "Interactions between nitrogen fertilizer and partial soil sterilization on the growth and yield of potatoes." Thesis, University of Reading, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370872.
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De, Oliveira Geraldo Deffune Goncalves. "Allelopathic influences of organic and bio-dynamic treatments on yield and quality of wheat and potatoes." Thesis, Imperial College London, 2000. http://hdl.handle.net/10044/1/62158.
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To verify the effectiveness of an established set of agricultural techniques involving application of natural solutions and extracts, crop rotations and associations - here collectively designated as Applied Allelopathy; a sequence of field, glasshouse and laboratory experiments was carried out from 1993 to 1997. Two test crops of world importance - wheat and potatoes, were chosen to provide responses from both a Mono and a Dicotyledon with physiologically different growing habits and end products (grains, tubers). The following treatments were tested: 1. Field sprays - used in sequence and additional to compost treatments: P500 soil spray (fermented cow manure), P501 plant spray (ground quartz), Nettle aqueous extract (Urtica dioica - planta tota), Equisetum axvense decoction and Kieselguhr (diatomaceous earth) suspension. 2. Compost additives P502 to P507 (200 mg.m-3) : Achilea millefolium - flowers, Matricaria recutita - flowers, Urtica dioica-planta tota, Quercus robur - bark, Taraxacum officinale - flowers and Valeriana officinalis - flowers' liquid extract. 3. Rotations with a Rye-Vetch mixture for assessment on crop responses and weed suppression through green manuring and mulching. The specific objective is to identify whether and/or which of the biodynamic preparations, organic and mineral extracts and rotations with weed suppressing green manures, do have allelopathic effects on the yield and quality (e.g., baking and storage properties) of wheat and potatoes. A general objective is to develop and test an integrated set of simple methodological designs that can combine systems (holistic) and analytical approaches, built upon a coherent critical philosophical-scientific foundation. Although the main scope of this research work is on the Agronomic aspects and results, some indications of the underlying physiological and biochemical mechanisms involved in the obtained results are given. Consecutive series of randomised complete block design (split-plots and factorials) field and glasshouse trials were carried out as blind-coded experiments, comparing Control, NPK, Organic and Biodynamic compost soil treatments, combined with field sprays and extracts in different dilutions. Results were based on field assessment of growth, biomass, weeds and yields; storage and laboratory analysis of quality parameters such as thousand grain weight (wheat TGW), Hagberg Falling Number (wheat HFN), dry matter and mineral contents, storage losses, grading and tissue browning (potatoes). The method of Selected Orthogonal Contrasts for partitioning the treatment sums of squares was used to allow specific comparisons between treatments. Significant differences using the F-test, were found both for the interaction of soil treatments and sprays overall in the field experiments and for several comparisons involving individual treatments and dilutions. The BD and organic systems offered significant positive differences in relation to the nil control, in terms of both yields (for both wheat and potatoes) and quality. This was expressed especially in the lower potato storage tissue browning and its resulting higher net amount of good marketable tubers, but also in the ideal wheat baking quality achieved by the BD treatment. Organic and BD yield increases did affect quality parameters like wheat TGW and potato DM%, which remained as high as in the control. They also did not cause any significantly different increase in soil nitrate and ammonium, actually displaying the same levels of these compounds as the control in the soil analysis results. The agrochemical treatment (Nitram for wheat, NPK for potatoes) produced significantly higher yields only in the wheat trials, but offered significantly lower values of wheat TGW and potato DM%, and very significantly increased soil nitrate levels in the soil, even after harvest time. The BD and organic systems did not differ in general in terms of yields, although there were trials like potato'93 in which the organic yielded significantly less than the agrochemical treatment, while the BD did not. It was in terms of both wheat and potato quality that the BD treatment system showed the following significant advantages, even over the comparatively equivalent organic system: • Ideal wheat flour baking quality (HFN, well-balanced alpha-amylase activity). • Significantly less potato tuber pest field damage and storage losses by tissue browning. Biodynamic and allelopathic sprays, like silica P501 and nettle water (Urtica dioica), can significantly improve yields and quality of both potatoes and wheat. However, their general mode of action can be defined as regulatory or "normalising", considering that when over-applied at near optimum crop conditions, they can reduce yields and negatively affect quality parameters. A green manure rotation and mulch like the rye plus vetch mix used in Experiments Three and Four (1994) can have significant effects, either beneficial (build-up of soil organic matter and weed suppression) or detrimental (allomonic action of allelochemicals present in the plant residues) on the subsequent crops. Silicon (Si) based sprays produced interesting results in the 1995 wheat and potato split-plot field trials, especially P501 in the interaction with the BD soil treatment system, which offered a significant opposite interaction response in relation to the other three systems. This phenomenon was expressed in the following results: • The DGA biomass samples of wheat, potato plants and weeds, which showed significantly contrasting growth curves and sample DWts between P501 and the water control spray. • While P501 increased the HFN in the BD system, it decreased HFN values in the other three systems. • While P501 sharply decreased total and ware potato yields in the BD system, it increased them in the other three systems. The opposite contrast occurred in relation to potato 'chat' yields, which increased in the BD system, while decreasing it in the other three systems. • P501 also increased the amount of storage browning in tubers from the BD system, while decreasing it in the other three systems. These results and the fact that the BD treatment system produced significantly contrasting results in relation to the other systems for most of the interactions observed, including the analytical approach field trials, support the hypothesis of a regulating or normalising effect of the BD preparations. They generally increase yields and improve quality under sub-optimal conditions, but cause limitations whenever applied beyond these optimum levels for specific parameters (Spiess, 1979; Raupp & Konig, 1996).
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Lewis, D. James. "Foliar-applied phosphate on potatoes (Solanum tuberosum L.) : factors affecting uptake by the leaves and the effects on growth and yield." Thesis, Open University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320528.
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De, Villiers Andre Jaco. "The influence of different calcium levels, irrigation methods and storage temperatures on the yield, quality and growth potential of G0 mini-tubers." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/2952.
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University of Stellenbosch. Faculty of Agrisciences. Dept. of Agronomy.Thesis (MScAgric (Agronomy)--University of Stellenbosch, 2007.
Calcium (Ca) is an important plant nutrient with many functions, such as strengthening of cell walls and maintaining membrane stability and cell integrity. A greenhouse experiment was conducted using an aeroponic production system, to evaluate the influence of different Ca: K & Mg ratios (consisting of a control [100% Ca], and three treatments in which the Ca levels were changed to 33%, 66% and 133% of the control, while the K and Mg levels were adjusted to compensate for the change in Ca) and two different irrigation methods (irrigation on roots only, and irrigation on roots and stolons) on tuber yield and mineral concentration. The treatment that received the highest Ca: K & Mg ratio had significantly more larger tubers than the lowest Ca treatment, although there was no significant difference in total tuber number between treatments. The high Ca treatment also had a significantly higher Ca concentration in the skin than the low Ca treatment. The site of irrigation did not have a significant effect on the total tuber number per plant, or on the Ca content of the tubers that were produced. The tubers produced in the first experiment were divided into two weight classes, and stored at three different temperatures. The percentage weight loss during storage was determined by weighing the tubers before, and again after storage. The firmness of the tubers was also measured after storage. Tubers were then stored in a dark room at room temperature to allow sprouts to develop. The sprouts of each tuber were counted and weighed. Weight loss was the lowest for tubers stored at 3oC. Firmness of the tubers increased as the Ca: K & Mg ratio of the nutrient solution used during production was increased. Number of sprouts was the highest for tubers stored at 6oC. Sprout number was also significantly higher for the larger tubers compared to the smaller ones. Total sprout weight was the highest for the tubers stored at 6oC, and was also the highest for the larger tubers. After sprouts started to develop, the tubers were planted again in the greenhouse, in sawdust and irrigated with a complete Steiner nutrient solution at 1.5 mS cm-1. After these plants were harvested, the leaf area and dry weight of the leaves were determined. The first generation tubers were counted and weighed. The only factor that had a significant influence on the growth of the plants, was the size of the seed tubers that were used. The larger seed tubers produced plants that had significantly higher leaf areas, dry weight of leaves, as well as higher yields than that of the plants produced from the smaller seed tubers. From the results of this study, it can be concluded that Ca has a definite positive effect on the quality of seed potatoes as well as the size of the tubers that are produced. This study also supported that seed tubers should be stored at low temperatures, around 3oC, to maintain the highest quality, while larger tubers proved to out-yield smaller ones.