Dissertations / Theses on the topic 'Dry matter accumulation'

Several investigations of dry matter accumulation by Upland cotton (Gossvpium hirsutum L.) have been conduced, however no investigations of this type have included American Pima cotton (G. barbadense L.). We conducted a study to describe the total dry matter accumulation and partitioning of that dry matter into various plant parts for both Upland and Pima cotton. During the growing seasons of 1990, 1991, and 1992 at two south-central Arizona locations, both Upland (var. DPL 90) and Pima (var. S-6) cotton were grown. Beginning 14 to 20 d after emergence, whole cotton plants were removed and cotton plants were separated into stems, leaves (including petioles), burs (carpel walls), lint, and seeds. The bur fraction, also included squares, flowers, immature bolls, and burs from mature bolls, Regression analyses was used to model nutrient uptake as a function of both days after planting (DAP) and heat units after planting (HUAP). Regression analyses indicated that HUAP was equally good, and in most cases superior to using DAP to model dry matter accumulation and partitioning within both Upland and Pima cotton. The general patterns of dry matter partitioning for Upland and Pima cotton are similar. However, Upland and Pima differ in the relative amount of dry matter incorporated into reproductive (bur, seed, and lint) and vegetative (leaf and stem) structures. Upland cotton produced 3527 lb /acre more total dry matter than Pima cotton. At the end of this study the vegetative /reproductive ratio for Upland was 83% compared to 70% for Pima. Upland was also more efficient at partitioning lint dry matter within the total dry matter of the reproductive structures. Dry matter incorporated into reproductive structures was 23% lint for Upland, compared to only 14% lint in Pima cotton. In summary, Upland placed more total dry matter into reproductive structures, and of the amount placed into reproductive structures, a greater proportion was incorporated into lint, when compared to Pima cotton.

Thesis (M.Sc. (Agronomy )) --University of Limpopo, 2007
Intercropping is the growing of two or more crops simultaneously on the same field, and it is a common traditional practice among resource-poor farmers throughout the Limpopo Province of South Africa. Field studies were conducted at two locations in the province namely, the University of Limpopo experimental farm at Syferkuil, and a farmer’s field at Dalmada during the 2002/2003 growing season, to determine patterns of nodulation in cowpea and lablab varieties under sole culture and in an intercropping system with maize, variety SNK2147 and also to assess biomass accumulation and grain yielding abilities of the component crops in the system. The experiments were established as a randomized complete block design with three replications at each location. Treatments examined were sole maize, two cowpea cultivars: Bechuana white and Glenda; two lablab cultivars, Rongai and Common. The legumes were intercropped alternately within 90 cm inter-row spacing of maize, thus creating a distance of 45 cm between the maize and the legume rows. Cropping system had no effect on cowpea grain yield at Syferkuil, but at Dalmada cowpea yield was reduced. Maize grain yield was significantly affected by the cropping system at both Syferkuil and Dalmada. At both locations, the yields of all the intercropped maize were lower than those of the sole crop maize. The dry matter production of different cropping systems was generally similar during the different sampling dates.
the National Research Foundation,and the Gauteng Department of Agriculture Conservation and Environment

Thesis (M.Sc. (Agriculture)) --University of Limpopo, 2008
Maize is a dominant crop in smallholder farming systems in the Limpopo province of South Africa, generally cultivated as intercrop with grain legumes. The major constraint in this cropping system is inadequate soil moisture during the growing season, which also limits nutrient availability to the component crops. The minimum tillage system has been reported to improve soil moisture availability on farmers’ fields but this has not yet been verified in an intercropping system in the province. The objective of this study was to quantify grain yield and chlorophyll production of intercropped maize, and to assess seasonal moisture availability under minimum tillage (MT) and conventional tillage (CT) systems. Dryland field experiments were conducted at two locations in the province namely, farmer’s field at Dalmada in 2002/2003 and 2003/2004 growing seasons and at the University of Limpopo Experimental farm at Syferkuil during the 2003/2004. The experimental design was a randomized complete block in split plot arrangement at all locations and seasons. Tillage systems consisting of conventional tillage and minimum tillage were the main plot treatments, whereas five different cropping systems namely, sole maize, and maize intercrop with cowpea (variety, Bechuana White), cowpea (variety, Agripers), Lablab bean (variety, Rongai) and Velvet bean were assigned as sub-plot treatments. Maize grain yield in 2002/2003 at Dalmada was significantly lower (357 kg/ha) under CT relative to 755kg/ha under MT. In 2003/2004 at Dalmada, grain yields under the two systems were similar, where as at Syferkuil, 15% higher grain yield results was obtained under MT. Minimum tillage systems resulted in higher number of maize cobs per plant at Dalmada in both growing seasons and weight per cob was higher under MT at both locations and seasons. At Dalmada, significantly higher soil moisture was recorded under the MT relative to the CT depending on depth and sampling dates. Chlorophyll content of the youngest fully expanded leaves of maize was generally higher under MT than CT, but this was observed only at the later stages of plant growth. The results also showed that the rate of senescence (reduced chlorophyll content in older leaves) was higher in maize plants grown under CT relative to those under MT. The minimum tillage system has shown the potential of being a superior system for dryland maize production, but further research involving additional locations is required to ascertain this fact.

Currently, livestock production in the Andean highlands of Bolivia is done with low food efficiency due to the free range grazing system. This in turn leads to nutritional deficiencies. Therefore, it is necessary to substitute these grass species for others that fulfill nutritional requirements. Our main objective was to determine the species of grass with the best nutritional quality. Of the 12 species, only 11 were analyzed because the species Didtichlis stricta did not germinate. Five monthly samples were taken after the cut (ddc) at the following intervals: 50, 81, 112, 141, and 176 days. These samples were analyzed in the Laboratory of Animal Nutrition via the Weende method. After analyzing the results statistically, it was determined that Agrophyrum elongatum and Festuca aranduniceae were the species that had the highest dry matter yields (9.74 and 8.78 t/ha-1 respectively). In addition, they had higher content of ash, fats, protein, fiber carbohydrates, total digestible nutrients, and digestible energy than the other species also considered as forage with good nutritional quality. We also found that dry matter yield was highest at 209 and 193 days after the cut (ddc).

Prinos zrna predstavlja jednu od najznačajnijih i najsloženijih osobina u oplemenjivanju biljaka. Poznavanje razvića, rastenja i akumulacije suve materije, omogućava pravilan odabir genotipova i odgovarajuće tehnologije gajenja. Cilj istraživanja je bio da se izvrši ispitivanje filohrona, akumulacije i translokacije suve materije nadzemnog dela biljaka, prinosa zrna i komponenti prinosa, različitih genotipova ozime pšenice i ječma sejanih u više rokova setve i vegetacionih sezona. Zatim da se utvrdi odgovarajuća jednačina koja opisuje akumulaciju suve materije i pojavu listova na glavnom stablu ječma i pšenice u funkciji sume temperatura tokom različitih rokova setve i vegetacionih sezona. U ogled je bilo uključeno po šest genotipova ozimog dvoredog ječma i ozime pšenice različitog porekla, pedigrea i agronomskih osobina, sejanih dve sezone u četiri roka setve. Sredinom cvetanja i u punoj zrelosti, uzeto je 10 slučajno odabranih biljaka. Na uzetim biljkama određena je masa pojedinačnih organa i komponente prinosa, kao i translokacija suve materije i doprinos asimilata akumuliranih pre cvetanja u masi zrna. Za utvrđivanje filohrona i ukupnog broja listova, dva puta nedeljno se očitavao broj listova na obeleženim biljkama tokom čitave sezone. Istovremeno se uzimao i uzorak od pet biljaka u cilju praćenja akumulacije suve materije. Sezona, rok setve i sorta su imali značajan uticaj na variranje ukupnog broja listova i filohrona kod ječma i pšenice. U proseku, sorte ječma su formirale više listova u odnosu na pšenicu, dok se pšenica karakteriše dužim filohronom. Kasnija setva dovela je do značajnog smanjenja broja listova i skraćenja filohrona kod obe vrste. U zavisnosti od sezone, roka setve, sorte i njihove interakcije menjala se i biomasa biljaka u cvetanju i prinos zrna. Translokacija suve materije je bila u pozitivnoj korelaciji sa biomasom biljaka u cvetanju. Akumulacija biomase nadzemnog dela biljaka tokom sezone, pratila je tipičan sigmoidni obrazac u svim kombinacijama rokova setve i sorti. Od tri posmatrane nelinearne jednačine, Logistička jednačina se pokazala najprikladnijom za opisivanje akumulacije suvematerije tokom sezone kod ječma i pšenice. Rezultati istraživanja ukazuju na značaj vegetativne mase biljaka u cvetanju, koja predstavlja bitan izvor asimilata za translokaciju u zrno. Ovi rezultati ukazuju da je tokom oplemenjivanja strnih žita, neophodno stvarati genotipove sa većim brojem listova koji bolje nakupljaju biomasu, odnosno genotipove koji će u optimalnom roku setve, imati usklađen fenološki razvoj sa agroekološkim uslovima u području Panonske nizije.
Grain yield is one of the most important and complex traits in plant breeding. Knowledge about crop development, growth and dry matter accumulation enables the appropriate selection of genotypes and field technology. The aims of this study were to investigate the variability of phyllochron, dry matter accumulation and translocation, grain yield and yield components of various wheat and barley genotypes, in relation to the sowing date and growing season. Furthermore, the goal was to find the equation that would appropriately describe dry matter accumulation and leaf appearance of wheat and barley. Six winter barley and six winter wheat genotypes, characterized by different origin, pedigree and agronomic traits, were sown in two growing seasons across four sowing dates. At the anthesis and physiological maturity, 10 randomly selected plants were manually cut at ground level. Dry mass of different plant organs, yield components, dry matter translocation and contribution of pre-heading dry matter to grain yield were determined. To determine the leaf number and phyllochron, measuring was done according to the Haun scale on three tagged plants per replication three times per week. Also, samples consisting of five plants were collected to determine dry matter accumulation. Growing season, sowing date and variety had significant influence on the final leaf number and phyllochron of wheat and barley. At average, barley varieties had more leaf compared to wheat, while wheat had higher phyllochron values. Late sowing reduced the final leaf number and phyllochron in both barley and wheat. Furthermore, growing season, sowing date, variety and sowing date × variety interaction had significant influence on crop biomass at anthesis and grain yield. Dry matter translocation was in positive correlation with dry matter content at anthesis. Dry matter accumulation across growing seasons had a typical sigmoid pattern in every combination of sowing date and variety. Among studied models, the logistic equation was the most appropriate for description of dry matter accumulation in wheat and barley. Results from this study highlight the importance of dry matter content at anthesis, which represent a significant source of assimilates for translocation into the grain. These results indicated that during the selection of small grain cereals, it is necessary to develop genotypes characterized by higher leaf number and increased biomass, i.e. genotypes that in optimal sowing dates, have an adjusted phenological development to the agro-ecological conditions of the Panonian plane.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
This work examines the accumulation of nutrients of the lulo plants under field conditions. The work was carried out from November 2010 to July 2011, at the precipice orchard belonging to the Federal University of Viçosa, in Viçosa, Minas Gerais State, Brazil. The experimental design was in randomized complete blocks with four replications. The treatment consisted of fifteen collection dates, beginning 30 days after transplanting (DAT), at 15 day intervals. The collected plants were fractionated into leaves, stems and fruits, dried and subjected to determination of nutrients concentration (N, P, K, Ca, Mg, S, Fe, Cu, Zn, and Mn). From the concentration of this nutrients and dry mass of the leaves, stem and fruits, it was determined the accumulation of nutrients in different parts of plants and total plant in each time. It was evaluated: dry matter accumulation in leaves, branches, fruits and total. The fruits provided higher production of dry mass in comparation to other organs. In the crop, at 240 days after transplanting (DAT), 45% of dry matter was allocated in the fruits 35% in the leaves and 20% in the stem. N and Fe were the macro and Micronutrients more absorved on the plant. The order of accumulation of nutrients was 28,684; 23,182; 9,148; 3,762; 1,846; 1,736 g.planta-1, respectively, for K, N, Ca, Mg, P, S e 442, 67; 80, 56; 30, 76; 6,63 mg.planta-1, respectively for Fe, Mn, Zn, Cu. The nutrients N, K, P, Ca, S and Cu accumulated preferentially in the fruits, while Mg, Fe, Zn and Mn accumulated in vegetative part. The period of large absorption of N and K of plants lulo was between 165 and 240 day after transplanting date, respectively.
Este trabalho teve como objetivo determinar o acúmulo de nutrientes pela cultura de lulo desenvolvida em condições de campo. O trabalho foi realizado no período de novembro de 2010 a julho de 2011, no pomar do Fundão pertencente a Universidade Federal de Viçosa, no município de Viçosa, Estado de Minas Gerais, Brasil. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições. Os tratamentos consistiram em quinze épocas de coletas iniciadas aos 30 dias após o transplantio, com intervalo entre coletas de 15 dias. As plantas coletadas foram fracionadas em folhas, caule e frutos; secas e submetidas a determinação das concentrações de nutrientes (N, P, K, Ca, Mg, S, Fe, Cu, Zn e Mn). A partir das concentrações desses nutrientes, e da massa seca de folhas, caule e frutos determinou-se o acúmulo de nutrientes em cada época. Foram avaliados: acúmulo de massa seca nas folhas, caule, frutos e total. Aos 240 dias após o transplantio (DAT), 45% da massa seca alocou-se nos frutos, 35% no caule e 20% nas folhas. O K e o Fe foram os macro e micronutrientes mais absorvidos pela planta. O acúmulo de nutrientes pelas plantas de lulo por ordem decrescente foi de 28,684; 23,182; 9,148; 3,762; 1,846; 1,736 g.planta-1, respectivamente para K, N, Ca, Mg, P, S e 442, 67; 80,56; 30,76; 6,63 mg.planta-1, respectivamente para Fe, Mn, Zn, Cu. Os nutrientes N, K, P, Ca, S e Cu acumularam-se preferencialmente nos frutos, enquanto Mg, Zn, Mn e Fe na parte vegetativa. O período de maior absorção de N e K pelas plantas de lulo foi entre 165-240 dias após o transplantio.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Swine production in southern Brazil is concentrated on small farms, seeking the recovery of waste as a source of nutrients crops of economic interest. The interaction between applications of pig slurry and soil management is common on small farms, however scarce information was found about the main responses of agricultural crops under this condition. Thus, the present work aimed to evaluate the use of pig slurry, associated with soil management in succession oat / maize and double purpose wheat / soybean. The experimental design was a factorial in a randomized complete block design, with four replications. The treatments consisted of doses of pig slurry (without manure, 20, 40, 80 m3 ha-1), and mineral fertilizer in three different soil management: no tillage, chiseling and chiseling + disking. The application of pig slurry was held before oat/maize and wheat crops sowing, and the soil management employed only before the establishment of winter crops. The application of pig slurry in succession oat / maize showed increases in dry matter yield, and in the accumulation of nitrogen, phosphorus and potassium, and in the grain yield. As for soil management, no-tillage favored the production of oat dry matter yield and soybean grain yield. However, the dual-purpose wheat proved to be low responsive to soil management employed. As for maize, the interaction between higher doses of pig slurry and with tillage managements promotes increases in grain yield. The application of pig slurry before the dual purpose wheat sowing promoted increases in dry matter production and grain yield. The residual effect of five applications of pig slurry does not alter the soybean grain yield.
A produção de suínos no Sul do Brasil concentra-se em pequenas propriedades rurais, que buscam o aproveitamento dos resíduos como fonte de nutrientes as culturas agrícolas de interesse econômico. Aplicação de dejeto líquido de suínos e manejos de solo diferenciados é comum em pequenas propriedades rurais, no entanto são escassas informações sob as repostas das principais culturas agrícolas frente a esta condição. Nesse sentido, o trabalho teve por objetivo avaliar a influência do uso de dejeto líquido de suínos, associado a manejos de solo na sucessão aveia/milho e trigo duplo propósito/soja. O delineamento experimental foi de blocos ao acaso em esquema fatorial, com quatro repetições. Os tratamentos constaram da interação de doses de dejeto líquido de suínos (sem dejeto, 20, 40, 80 m3 ha-1), e adubação mineral, em três diferentes manejos de solo: plantio direto, escarificado e escarificação + gradagem. A aplicação do dejeto líquido de suínos foi realizada antes da semeadura das culturas aveia, milho e trigo, os manejos de solo realizados antes do estabelecimento das culturas de inverno. A aplicação de dejeto líquido de suínos na sucessão aveia/milho promoveu incrementos na produção de matéria seca, no acúmulo de nitrogênio, fósforo e potássio, e na produtividade de grãos. Quanto aos manejos de solo, o plantio direto favoreceu a produção de matéria seca da aveia e a produtividade de grãos de soja. Já para o milho, a interação entre maiores doses de dejeto líquido de suínos e manejos com revolvimento do solo promove incrementos na produtividade de grãos. A aplicação do dejeto líquido de suínos antes da semeadura do trigo duplo propósito promove incrementos na produção de matéria seca e na produtividade de grãos. O efeito residual de cinco aplicações de dejeto líquido de suínos não altera a produtividade de grãos de soja.

Orientadora: Ana Cláudia Ruggieri
Banca: André Fischer Sbrissia
Banca: Kleber Tomás de Resende
Resumo: A produção de forragem é influenciada pelas estratégias de manejo impostas a ela, desta maneira, as técnicas para identificação do melhor momento para início e término do pastejo, aliadas aos estudos das características morfogênicas e estruturais das plantas, tornam-se úteis para direcionamento do manejo, pois buscam auxiliar no melhor entendimento do crescimento vegetal, e por conseqüência, da produção forrageira. O experimento foi realizado no setor de Forragicultura, em área pertencente à FCAV da UNESP - Jaboticabal no período de dezembro de 2008 a abril de 2009, com o objetivo de avaliar o efeito de índices de área foliar residual (IAFr) sobre as características morfogênicas e estruturais, além do acúmulo de forragem em pastos de Cynodon spp cv Tifton-85 sob regime de lotação rotacionada com ovinos. Os tratamentos foram constituídos por três IAFr, 2,4, 1,6 e 0,8, mantidos por regime de lotação rotacionada com ovinos. O delineamento experimental utilizado foi o de blocos completos casualizados em arranjo de parcelas subdivididas no tempo com sete repetições, totalizando 21 unidades experimentais. Foram avaliadas nas condições de pré e pós-pastejo, as alturas do dossel, os IAF e a massa de forragem, além da taxa de acúmulo de forragem e as características morfogênicas e estruturais dos pastos. No pré e pós-pastejo as alturas médias e o IAF do dossel se comportaram de forma análoga, decrescendo com a diminuição dos IAFr. O maior valor de interceptação luminosa no pós-pastejo (68,19%), foi verificado para o IAFr 2,4 e o menor valor (35,57%) para o IAFr 0,8. A taxa de aparecimento de folhas foi maior para o dossel mantido sob IAFr 0,8 em função da sua menor taxa de alongamento de colmos (0,51 cm/perfilho.dia). Os pastos mantidos sob IAFr 0,8 apresentaram maior densidade populacional de perfilhos. A massa de forragem seca... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The production of forage is influenced by handling strategies imposed on the techniques to identify the best moment for the beginning and ending of grazing, linked to the studies of morphogenetic and structural characteristics of plants, become useful tools for the directing of management for they aim to aid the best understanding of vegetal growth, and as consequence, forage plants. The experiment was conducted at Setor de Forragicultura at Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, at UNESP - Jaboticabal from December 2008 to April 2009, and aimed to evaluate the effect of residual leaf area index (LAIr) about the morphogenical and structural characteristics, and forage accumulation in pastures of Cynodon spp cv Tifton-85 in a rotational stocking system with sheep. The treatments were constituted by three LAIr, 2,4, 1,6 e 0,8, maintained by rotational stocking with sheep. A complete randomized block design was used arranged in sub-divided parcels with seven replications, totaling 21 experimental units. They were evaluated in pre and post-grazing conditions, the height of the sward, LAI and forage mass, besides the accumulation of forage rate and the morphogenetic and structural characteristics. In the pre and post-grazing, the average height and the LAI of sward, decreasing with the diminishing of LAIr. The biggest value of light interception in post-grazing (68,19%), was verified by LAIr 2,4 and the smallest value (35,57%) for LAIr 0,8. The stem elongation rate (0,51 cm/tiller.day). The grazing maintained by LAIr 0,8 had higher tiller population density. The total dry forage mass was 27,1% superior for LAIr 2,4 regarding to LAIr 0,8 in pre-grazing conditions, being this total production, 72,0% was composed by stem fractions and dead material. The biggest rates of dry matter accumulation were observed with LAIr 2.4, in the second and third grazing cycles... (Complete abstract click electronic access below)
Mestre

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The cowpea crop has great importance for the Brazilian Northeast, especially for the poorest population. One of the major problems encountered for this crop is drought stress caused by erratic rainfall, coupled with the high temperatures common in this region. The no-tillage system has features, such as reduction of soil water evaporation, higher water retention and lower soil temperature fluctuations, and can be a way to minimize the water stress in a cowpea crop. Thus, this study aims to obtain information on growth, yield components and cowpea yield under moisture stress in no-tillage and conventional crop systems. For this purpose an experiment was conducted at Universidade Federal Rural do Semi-Arido, in a split plot with randomized complete blocks design with four replications, using the cowpea cultivar BRS Guariba, and no-tillage and conventional crop systems treatments. For the dry spells simulation, irrigation systems has been suspended at 34 days after sowing, during the onset of flowering, for periods of 2, 6, 10, 14, 18 and 22 days, after what the irrigation was resumed. To evaluate the effect of the crop systems and moisture stress on growth, samples were taken between 15 and 64 days after sowing, in the treatments with and without irrigation (22 days duration). The evaluation of yield components (pod length, number of grains per pod, number of pods per plant and hundred grains weight) and yield was performed at 70 days after sowing. The tillage systems influenced the leaf area, and stem leaf, pod and plant dry weight. The growth rates were influenced by the plant phenological phase (age) and by water stress. The highest growth rates were achieved in the no-tillage system. Water stress affected negatively all the variables, regardless of tillage system. The no-tillage system was more productive both for the irrigated and the stress treatments. The dry spells periods affected grain yield and all other yield components studied in a negative way, except for the hundred grains weight. Among the systems studied, the no-tillage system provides higher values for the yield components, except for the hundred grains weight
A cultura do feijão-caupi possui grande importância para a região Nordeste, principalmente para a população mais carente. Um dos grandes problemas encontrados para essa cultura é o estresse hídrico, provocado pela irregularidade das chuvas, aliado a altas temperaturas, comuns a esta região. O sistema de plantio direto possui características como redução da evaporação da água do solo, maior retenção do solo e menores oscilações da temperatura, e pode ser uma forma de minimizar o efeito do estresse hídrico para a cultura do feijão-caupi. Deste modo, o presente trabalho se propõe a obter informações relativas ao crescimento, componentes da produção e rendimento de feijão-caupi sob veranico nos sistemas de plantio direto e convencional. Para isso, foi realizado, na Universidade Federal Rural do Semi-Árido, um experimento em delineamento de blocos completos casualizados em parcelas subdivididas com 4 repetições, utilizando-se a cultivar de feijão-caupi BRS Guariba em plantio direto e convencional. Para aplicação do veranico, a irrigação foi suspensa nos sistemas aos 34 dias após a semeadura por períodos de 2, 6, 10, 14, 18 e 22 dias sem irrigação, ocasião em que foi verificado o início do florescimento. Para avaliar o efeito dos sistemas e do veranico no crescimento, foram realizadas coletas entre os 15 e 64 dias após a semeadura, nos tratamentos com e sem irrigação (22 dias de duração). A avaliação dos componentes de produção (comprimento de vagem, número de grãos por vagem, número de vagens por planta e peso de cem grãos) e rendimento de grãos foi realizada aos 70 dias após a semeadura. Os sistemas de plantio influenciam o crescimento da área foliar, da matéria seca do caule, de folhas, de vagens e total do feijão-caupi. Os índices de crescimento são influenciados pela fase fenológica da planta (idade) e pelo estresse hídrico. As maiores taxas de crescimento foram alcançadas no sistema de plantio direto. O estresse hídrico afetanegativamente todas as variáveis avaliadas, independentemente do sistema de plantio. O sistema de plantio direto é mais produtivo do que o convencional quando em irrigação e em condição de estresse. Os períodos de veranico influenciaram o rendimento de grãos e todos os componentes de produção estudados de forma negativa, com exceção do peso de cem grãos. Entre os sistemas estudados, o direto é o que proporciona maiores valores para os componentes de produção, exceto peso de cem grãos

Destacam-se as semelhanças entre os nutrientes boro (B) e cálcio (Ca) quanto às formas e as funções que eles exercem nos vegetais. Partindo do princípio que a interação Ca - B afeta os atributos morfológicos, ultraestruturais e bioquímicos, bem como a nodulação nas plantas leguminosas, objetivou-se com esse estudo determinar a relação Ca:B mais adequada para a produção de grãos e matéria seca de soja, bem como avaliar os efeitos da interação B e Ca na fixação biológica de N2 (atividade da nitrogenase -N-ase [EC 1.18.6.1]), na morfologia de raízes (comprimento e superfície total), anatomia de raízes (nódulos) e de folhas, assim como as avaliações ultraestruturais dos mesófilos foliares, rendimento do teor de óleo nos grãos das plantas de soja (cultivar BRS 284), crescidas em solução nutritiva. Foram avaliadas ainda a produção de massa seca das plantas, as concentrações e os acúmulos de Ca, B, Mg, K e N na parte aérea e raízes. Foi empregado um esquema fatorial 5² incompleto, perfazendo treze combinações de doses de Ca (mmol L-1) e B (µmol L-1), as quais foram distribuídas segundo o delineamento experimental de blocos ao acaso, com quatro repetições. As maiores atividades da N-ase foram obtidas com as maiores doses de Ca e B (7,25 mmol L-1 de Ca e 50 µmol L-1 de B). A menor dose de Ca resultou na inibição da N-ase em cerca de 90%. Os maiores comprimentos e superfícies totais de raízes foram obtidos na combinação de doses de 7,25Ca e 12,5B, enquanto que para a combinação das menores doses de Ca e B observou-se uma redução de cerca de 70% e 60% para comprimento e superficial de raízes, respectivamente. A maior produção de biomassa seca das plantas e de grãos, os maiores acúmulos de Ca, B, N, K e Mg nas folhas e o maior rendimento de óleo foram obtidos com o fornecimento de 4,25 mmol L-1 de Ca e 12,5 µmol L-1 de B, observando-se relação Ca:B na solução nutritiva próxima de 350:1 e nas folhas de 700:1. O teor de óleo nos grãos incrementou cerca de 20% com o aumento das doses de B de 3,125 para 50 µmol L 1. O número de camadas de células do córtex dos nódulos aumentou com o incremento das concentrações de Ca e B na solução. Observou-se ruptura da membrana dos cloroplastos no mesófilo foliar e elevado número de bactérias fixadoras de N2 penetrando o interior dos tecidos nodulares quando as plantas foram submetidas ao menor suprimento de Ca e maior de B. A combinação da menor dose de B junto a maior dose de Ca provocou ruptura da parede celular e o espessamento da lamela média das folhas. O aumento no fornecimento de Ca ameniza os efeitos negativos do baixo suprimento de B na produção de biomassa das plantas e de grãos, no comprimento e superfície de raízes e na atividade da nitrogenase. A relação Ca:B, tanto na solução, quanto no tecido vegetal, não pode ser entendida como parâmetro exclusivo de equilíbrio nutricional
Regarding mineral nutrition of plants, we highlight the similarities between nutrients boron (B) and calcium (Ca) in relation to similar functions they play in plant physiology. However, the mechanisms involved in the interaction between these nutrients are not very well known. Assuming that the interaction Ca - B affects the morphological, ultrastructural and biochemical attributes, as well as the nodulation in leguminous plants, the objective with this study was to determine the optimum Ca:B ratio, in the solution and plan tissue as well for dry matter yield of grain and dry matter of soybean, and to evaluate the effects of B - Ca interaction in the biological N2 fixation (nitrogenase activity - N-ase [EC 1.18.6.1]), root morphology (total root length and total root surface area), root anatomy (nodules), as well as in the ultrastructural evaluation of foliar mesophilic, and yield of oil content of soybean (cultivar BRS 284), grown in nutrient solution. Dry matter yield of plants, Ca-concentrations and amounts of Ca, B, Mg, K and N in shoots and roots were also evaluated. The experimental arrange used was an incomplete 5² factorial, making thirteen combinations of Ca (mmol L-1) and B (µmol L-1) rates, which were set in a randomized block design, with four replications. The highest N-ase activity was obtained with the highest doses of Ca and B (7,25 mmol L-1 of Ca and 50 µmol L-1 of B). The lowest Ca rate resulted in approximately 90% inhibition of N-ase. The highest total root length and total root surface area were obtained with combination of 7,25Ca and 12,5B rates, whereas the combination of the lowest Ca and B rates caused reduction of approximately 70% and 60% on root length and area, respectively. The highest dry matter and grain yield, highest accumulations of Ca, B, N, K and Mg on the leaves and the highest oil content in grains were obtained when 4,25 mmol L-1 of Ca and 12,5 µmol L-1 of B were supplied, resulting in a Ca:B ratio of approximately 350:1 on nutrient solution and 700:1 on leaves. The oil content in grains raised about 20% increasing B rates from 3,125 to 50 µmol L-1. The number of cell layers of nodule cortex raised with increasing Ca and B levels in the solution. It was observed membrane rupture of chloroplasts in leaf mesophyll and high number of N2-fixing bacteria entering the interior of nodular tissues when plants were supplied with the lowest Ca rate (1,75Ca) and the highest B (50B). The combination of the lowest B rate (3,125B) and the highest Ca rate (7,25) caused cell wall rupture and thickening of the middle lamella on the leaves. The increase of Ca levels on the solution mitigates the negative effects of the low B supply in plant biomass and grain yield, in root length and root surface area and in N-ase activity. The Ca:B ratio either in the solution or plant tissue, cannot be understood as an exclusive parameter of nutritional status

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
A produção de forragem é influenciada pelas estratégias de manejo impostas a ela, desta maneira, as técnicas para identificação do melhor momento para início e término do pastejo, aliadas aos estudos das características morfogênicas e estruturais das plantas, tornam-se úteis para direcionamento do manejo, pois buscam auxiliar no melhor entendimento do crescimento vegetal, e por conseqüência, da produção forrageira. O experimento foi realizado no setor de Forragicultura, em área pertencente à FCAV da UNESP – Jaboticabal no período de dezembro de 2008 a abril de 2009, com o objetivo de avaliar o efeito de índices de área foliar residual (IAFr) sobre as características morfogênicas e estruturais, além do acúmulo de forragem em pastos de Cynodon spp cv Tifton-85 sob regime de lotação rotacionada com ovinos. Os tratamentos foram constituídos por três IAFr, 2,4, 1,6 e 0,8, mantidos por regime de lotação rotacionada com ovinos. O delineamento experimental utilizado foi o de blocos completos casualizados em arranjo de parcelas subdivididas no tempo com sete repetições, totalizando 21 unidades experimentais. Foram avaliadas nas condições de pré e pós-pastejo, as alturas do dossel, os IAF e a massa de forragem, além da taxa de acúmulo de forragem e as características morfogênicas e estruturais dos pastos. No pré e pós-pastejo as alturas médias e o IAF do dossel se comportaram de forma análoga, decrescendo com a diminuição dos IAFr. O maior valor de interceptação luminosa no pós-pastejo (68,19%), foi verificado para o IAFr 2,4 e o menor valor (35,57%) para o IAFr 0,8. A taxa de aparecimento de folhas foi maior para o dossel mantido sob IAFr 0,8 em função da sua menor taxa de alongamento de colmos (0,51 cm/perfilho.dia). Os pastos mantidos sob IAFr 0,8 apresentaram maior densidade populacional de perfilhos. A massa de forragem seca...
The production of forage is influenced by handling strategies imposed on the techniques to identify the best moment for the beginning and ending of grazing, linked to the studies of morphogenetic and structural characteristics of plants, become useful tools for the directing of management for they aim to aid the best understanding of vegetal growth, and as consequence, forage plants. The experiment was conducted at Setor de Forragicultura at Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, at UNESP – Jaboticabal from December 2008 to April 2009, and aimed to evaluate the effect of residual leaf area index (LAIr) about the morphogenical and structural characteristics, and forage accumulation in pastures of Cynodon spp cv Tifton-85 in a rotational stocking system with sheep. The treatments were constituted by three LAIr, 2,4, 1,6 e 0,8, maintained by rotational stocking with sheep. A complete randomized block design was used arranged in sub-divided parcels with seven replications, totaling 21 experimental units. They were evaluated in pre and post-grazing conditions, the height of the sward, LAI and forage mass, besides the accumulation of forage rate and the morphogenetic and structural characteristics. In the pre and post-grazing, the average height and the LAI of sward, decreasing with the diminishing of LAIr. The biggest value of light interception in post-grazing (68,19%), was verified by LAIr 2,4 and the smallest value (35,57%) for LAIr 0,8. The stem elongation rate (0,51 cm/tiller.day). The grazing maintained by LAIr 0,8 had higher tiller population density. The total dry forage mass was 27,1% superior for LAIr 2,4 regarding to LAIr 0,8 in pre-grazing conditions, being this total production, 72,0% was composed by stem fractions and dead material. The biggest rates of dry matter accumulation were observed with LAIr 2.4, in the second and third grazing cycles... (Complete abstract click electronic access below)

Genotypic differences in growth and yield of two common bean (Phaseolus vulgaris L) cultivars to Rhizobium inoculation and management were investigated. In 2003-04, the two bean cultivars (Scylla and T-49) were combined with three inoculant treatments (strains CC 511 and RCR 3644, and a control of no inoculation), two fertiliser levels (0 and 150 kg N ha⁻¹) and two irrigation treatments (irrigated and rainfed). There was no nodulation on either cultivar. To further investigate the symbiotic relationship, 16 rhizobial isolates, including the two used in the first field experiment, were combined with the cultivar Scylla and evaluated in a greenhouse. Subsequently, five Rhizobium isolates were chosen for further field evaluation, based on signs of early nodulation in the greenhouse trial. The second field experiment in 2004-05 combined the five inoculant strains (RCR 3644, UK 2, H 20, PRF 81, PhP 17 and a control) with two bean cultivars (Scylla and T-49). In the greenhouse, nodule number varied from 7 (UK 2) to 347 (H 441) nodules plant⁻¹ at 51 DAS and from 13 (UK 1) to 335 (CIAT 899) nodules plant⁻¹ at 85 DAS. In 2004-05, in the field, nodulation was also variable, ranging between 1 and approximately 70 nodules plant⁻¹, with higher nodules numbers plant⁻¹ being found on cultivar T-49. Of the isolates used in the field, strains H 20, PRF 81 and PhP 17 produced 70, 25 and 12 nodules plant⁻¹ at 70, 40 and 54 DAS respectively. Nodules formed were of various sizes and more than 80 % were pink to dark red in colour denoting the presence of leghaemoglobin and active N fixation. The remaining nodules were either green or white. The importance of selecting an appropriate cultivar for the growing conditions was highlighted in these experiments. Leaf area index, leaf area duration intercepted radiation and final utilisation efficiency were significantly affected by cultivar. In both seasons cv. T-49 reached maturity (dry seed) before Scylla, while unirrigated plants reached green pod maturity seven days before irrigated plants. Plants of cv. Scylla gave a final TDM of 730 g m⁻²; compared to the 530 g m⁻² produced by T-49. The average growth rate was 7.0 and 5.2 g m⁻² day⁻¹ for Scylla and T-49 respectively (2003-04). Plants receiving 150 kg N ha⁻¹ produced 665 g m⁻² TDM which was 12 % more than was produced by unfertilised plants. The application of 150 kg N ha⁻¹ gave an average growth rate of 6.4 g m⁻² day⁻¹ compared to 5.7 g m⁻² day⁻¹ from plants with no N. Inoculation in the field had no significant effect on TDM in both seasons. Temperature affected growth and DM accumulation. Accumulated DM was highly dependent on cumulative intercepted PAR. Air temperatures below the base temperature (10 °C) affected growth in 2004-05, resulting in plants accumulating just 0.24 g DM MJ⁻¹ PAR during early growth. This increased to 2.26 g DM MJ⁻¹ PAR when the temperature was increased above the base temperature. There was a strong relationship between LAI and intercepted PAR. A LAI of 4.0-4.5 was required to intercept 90-95 % of incident solar radiation. Cultivar significantly (p < 0.001) affected radiation use efficiency (RUE). Scylla had a RUE of 1.02 g DM MJ⁻¹ PAR compared to T-49 at 1.18 g DM MJ⁻¹ PAR. Seed yield was significantly (p < 0.001) affected by cultivar and fertiliser application. Cultivar Scylla produced 467 g m⁻² which was 76 % more than T-49, while a 12 % increase in seed yield was observed in N fertilised plants over unfertilised plants. Only cultivar significantly affected HI, while the yield components that had the greatest effect on seed yield were hundred seed weight and pods plant⁻¹. Inoculation significantly (p< 0.05) affected 100 seed weight (2004-05). Plants inoculated with strain H 20 had the highest 100 seed weight at 25.2 g with cv. Scylla producing larger seeds than T-49. The belief that local environmental conditions play a major role on field survival of bacteria, led to the use of PCR methods to identify field nodulating organisms. Amplification of genomic DNA from parent isolates using primers fC and rD generated a single band for each isolate. Isolates were identified to the species level as either Rhizobium or Agrobacterium, using the highly conserved internally transcribed spacer (ITS) region and are known to nodulate common bean. The DNA extracted from the isolates recovered from nodules of field grown beans gave multiple bands with primers fC and rD. Five distinct banding patterns were observed. All of these were different from those of parent isolates. Sequencing of the 16S rRNA demonstrated that nodules of field grown beans in Canterbury were inhabited by Pseudomonads either alone or in association with other root nodulating organisms. The inability to identify the inoculant strains in nodules of field grown beans does not rule out their infection and nodulating function in the cultivars used. The results suggest the possibility of both Rhizobium and Pseudomonads cohabiting in the nodules of field grown beans. The aggressive nature of Pseudomonads on artificial media, possibly out competing the inoculant rhizobia is proposed, leading to the inability to identify the inoculant strain from the nodules of the field grown beans by PCR methods. The need to identify the nodule forming or nodule inhabiting bacteria in the nodules is necessary to classify the importance of these organisms and their economic benefit to agricultural production. This study also underlines the importance of using PCR methods to gain valuable insights into the ecological behaviour of Rhizobium inoculants and nodule inhabiting organisms.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The common bean (Phaseolus vulgaris L.) is an important calcium source for human diet, thus the evaluation of the calcium use efficiency in common bean a relevant tool for crop sustainability. The aims of this study were to evaluate the response in common bean cultivars with different calcium concentrations in nutrient solution on dry matter production, yield components and calcium, potassium and magnesium accumulations; to investigate the association between these characters; to evaluate the genetic variability of lines for calcium availability in the solution; and identify lines of common bean-efficient and responsive to calcium application by different indexes. For this, three experiments were conducted from March 2011 to July 2012 in greenhouse, in a completely randomized design, in splitplots. In the first two experiments were tested calcium concentrations in nutrient solution from 1.10 to 4.95 mmol L-1 as components of the main plot and the BRS Expedito, Carioca and Iraí cultivars on subplots in the first experiment, with the exclusion of the cultivar Iraí in the second experiment. The third experiment evaluated the efficiency and the response of the calcium use of 12 different common bean lines at low (1.10 mmol L-1) and high (3.85 mmol L-1) calcium concentrations in the nutrient solution. Higher values for dry matter and grain yield components were observed for 3.30 mmol L-1 and 4.95 mmol L-1 calcium concentrations in the solution. The common bean cultivars acumulate greater quantity of calcium in the leaves, followed by stems, pods and grains. Highest accumulation of calcium in the leaves was obtained at a 4.95 mmol L-1 calcium concentration in the nutrient solution, and the calcium concentration in the leaves was 21 times higher than the value obtained in the bean grains. The increase of calcium concentration in the nutrient solution up to the concentration of 4.95 mmol L-1 does not change the absorption and the accumulation of potassium and magnesium in leaves and grains. Indirect selection by greater dry matter and higher values of the variables that form the grain yield in common bean will be efficient to increase the accumulation of calcium in grains. The lines L 15, L 234, L 246 and L 77 respond to the increase on calcium supply in the solution, because more calcium accumulates in grain in the cultivation with high calcium concentration. The lines L 246 and L 15 are calcium use efficient in the plant, in the acquisition and grain production, and are not responsive to calcium application. The line L 77 is calcium use efficient in the plant and in the grain production and is responsive to the calcium application in the nutrient solution.
O feijão (Phaseolus vulgaris L.) é uma importante fonte de cálcio para a alimentação humana, sendo a avaliação da eficiência no uso de cálcio em feijão uma ferramenta relevante para a sustentabilidade da cultura. Foram objetivos desse trabalho avaliar a resposta de cultivares de feijão a diferentes concentrações de cálcio em solução nutritiva na produção de massa seca, nos componentes da produtividade de grãos e no acúmulo de cálcio, potássio e magnésio; investigar a associação entre esses caracteres; avaliar a variabilidade genética de linhagens de feijão quanto a disponibilidade de cálcio na solução e identificar linhagens eficientes no uso de cálcio e responsivas a aplicação deste mineral por diferentes índices. Para isso foram realizados três experimentos no período de março de 2011 a julho de 2012, em casa-devegetação, em delineamento inteiramente casualizado, com parcelas subdivididas. Nos dois primeiros experimentos foram testadas concentrações de cálcio na solução nutritiva de 1,10 a 4,95 mmol L-1 como componentes da parcela principal e as cultivares BRS Expedito, Carioca e Iraí nas subparcelas no primeiro experimento, com a exclusão da cultivar Iraí para o segundo experimento. No terceiro experimento foram avaliadas a eficiência no uso e a resposta de 12 linhagens de feijão em baixa (1,10 mmol L-1) e em alta (3,85 mmol L-1) concentração de cálcio na solução nutritiva. Maiores valores para massa seca e para os componentes da produtividade de grãos foram observados para as concentrações de 3,30 mmol L-1 e de 4,95 mmol L-1. As cultivares de feijão acumulam maior quantidade de cálcio nas folhas, seguido pelos caules, vagens e grãos. Maior acúmulo de cálcio nas folhas foi obtido na concentração de 4,95 mmol L-1 de cálcio na solução nutritiva, quando a concentração de cálcio nas folhas é 21 vezes superior ao valor obtido nos grãos de feijão. O aumento da concentração de cálcio na solução nutritiva até a concentração de 4,95 mmol L-1 não altera a absorção e o acúmulo de potássio e de magnésio nas folhas e nos grãos de feijão. A seleção indireta pela maior massa seca de parte aérea e maiores valores das variáveis que formam a produtividade de grãos em feijão será eficiente para aumentar o acúmulo de cálcio nos grãos de feijão. As linhagens L 15, L 234, L 246 e L 77 respondem ao aumento do suprimento de cálcio na solução, pois acumulam mais cálcio nos grãos em cultivo com alta concentração deste mineral. As linhagens L 246 e L 15 são eficientes no uso de cálcio na planta, na aquisição de cálcio e na produção de grãos, e não são responsivas à aplicação de cálcio. A linhagem L 77 é eficiente no uso de cálcio na planta e na produção de grãos e é responsiva à aplicação de cálcio na solução nutritiva.

Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia
With the rising difficulties of every economical sector in the past few years, society saw and still sees itself forced to find better and less expensive ways of obtaining some essential goods and services. The increase of oil prices and of the demand of specific raw-materials by the emerging economies, mainly cereals, oleaginous plants and micronutrients, along with the energetic and environmental concerns, led the farmers and farming companies, to the inevitable need of arranging other alternatives within the production strategies. This tendency has the purpose of reducing the resort to the expensive concentrated fodder (principally due to the biodiesel and bioetanol industry), and synthesized fertilizers. In addition, the negative impact that some nutrients are known to have on human health, mainly N, began to arise environmental and agricultural goods quality, safeguard policies. With the contingences mentioned, a renewed interest in white clover (Trifolium repens L.), and other legumes, along with the performance of mixed swards receiving lower levels of N, is taking place. Legumes are known to establish symbiotic associations with Rhizobium, which in return allows the plant to benefit with atmospheric N fixed by the bacteria, meaning that the costs in fertilizers can be reduced. Thus, there are several reasons for finding and encouraging better ways of improving the nitrogen fertilizer use efficiency. A fertilizer trial was conducted for 5 months, in Faial Island, Azores, on a permanent pasture, mainly consisting of perennial ryegrass (Lolium perenne L.), cocksfoot (Dactylis glomerata L.), italian ryegrass (Lolium multiflorum Lam.), white clover and red clover (Trifolium pratensis L.). The pasture is established on a light, well drained soil, classified as an Andissol, with an organic matter content of 5,17% and pH-H2O of 6,2. At the time, available phosphate was low (20 mg P2O5 kg-1 dry soil), and the potassium content very high (>200 mg K2O kg-1 dry soil). The aim of the experiment was to evaluate the effect of a range of 7 nitrogen levels and the traditional fertilization, on the dry matter accumulation (DM at 60-65 ºC and 100-105 ºC, the last one only evaluated for treatments 0, 40, 80, 120 kg N ha-1 and traditional fertilization), botanical composition and some quality parameters, namely organic matter (OM) and crude protein (CP). Seven N levels were tested, N0, N1, N2, N3, N4, N5, N6, corresponding to 0, 20, 40, 60, 80, 100 and 120 kg N ha-1. The traditional fertilization consisted on the application of 480 kg ha-1 of synthesized compost, adding up 125 kg N ha-1, plus Ca, Mg and S. The effect of the treatments on the sward was evaluated in 5 consecutive cuts during the trial. The botanical composition was evaluated, resorting to sub-samples collected from the cut material, where grasses, legumes, other species and debris were manually separated, and dried at 60-65 ºC for 48 h, to assess their percentage on total DM, after each cut. The compostition of legumes in the sward according to the treatments 0, 20, 40, 60, 80, 100, 120 kg N ha-1 and traditional fertilization, corresponded to 2.66, 5.54, 4.45, 0.40, 5.24, 0.80, 2.68 and 4.31% respectively. The OM was evaluated in percentage on DM, and the CP in mass and percentage on DM. The increase of N levels resulted in an increase of DM accumulation, mainly due to the enhancement of grasses, and the depressing of the legumes proportion. The DM (at 100-105 ºC) accumulation of the treatments 0, 40, 80, 120 kg N ha-1 and traditional fertilization, corresponded to 1.85, 1.88, 2.02, 2.37 and 2.11% respectively. Also the CP increased with N treatments, but had no significant effect on the levels of OM. The proportion of CP in the DM according to the treatments 0, 40, 80, 120 kg N ha-1 and traditional fertilization, corresponded to 12.71, 13.99, 14.52, 14.86 and 14.23% respectively. The cutting season had a significant effect on the grasses and legumes proportion, DM accumulation, and quality parameters of the pasture. The traditional fertilization revealed not to be the most adequate one, whilst treatment N4, corresponding to the application of 80 kg N ha-1, seems the one more suitable for the farm exploration, since it resulted in high proportions of legumes (5,24%) and CP (14,52%), without reducing significantly the DM, compared with other treatments.