Claudemir Zucareli

Maturacao, formas de secagem e qualidade fisiologica de sementes de mucuna-preta

RESUMO – O objetivo deste trabalho foi verificar o efeito das formas de secagem, durante a maturacao, sobre o desenvolvimento e a qualidade fisiologica de sementes de mucuna-preta. No primeiro experimento, inflorescencias foram etiquetadas no inicio de florescimento e as colheitas iniciaram-se duas semanas apos; no segundo, as colheitas foram iniciadas 40 dias apos 50% de florescimento das plantas; em ambos, as colheitas foram feitas a intervalos semanais ate o estadio de vagens secas. As sementes de cada colheita do primeiro experimento foram secadas, em condicoes ambientais de laboratorio, no interior de vagens fechadas ou abertas (sementes expostas) e determinados a massa de 100 sementes, o comprimento, a largura e a espessura das sementes, enquanto no segundo foram secadas no interior de vagens fechadas ou extraidas das vagens e submetidas ao teste de germinacao. A secagem no interior das vagens promove o desenvolvimento de sementes imaturas, antecipa a formacao de sementes duras e aumenta o numero dessas nas imaturas comparativamente as sementes secadas em vagens abertas ou apos a extracao. Termos para indexacao: Mucuna aterrima, colheita, germinacao, dormencia MATURATION, DRYING AND PHYSIOLOGICAL QUALITY OF VELVET BEAN SEEDS

Fósforo na produtividade e qualidade de sementes de feijão Carioca Precoce cultivado no período das águas

-1 ), aplicados no sulco da semeadura na forma de superfosfato triplo, com cinco repeticoes. A produtividade de sementes foi determinada com base na massa das sementes produzidas na area util da parcela experimental. A qualidade das sementes foi avaliada por meio das seguintes determinacoes: massa de 100 sementes, teor de agua, germinacao, primeira contagem, teor de agua apos o envelhecimento acelerado, germinacao apos o envelhecimento acelerado, condutividade eletrica, emergencia de plântulas no campo e massa de materia seca de plântulas. A produtividade de sementes do feijao Carioca Precoce, cultivado no periodo das aguas, aumentou linearmente em funcao do suprimento de P. A massa de 100 sementes e a qualidade fisiologica das sementes nao foram alteradas pelo incremento das doses de P. Palavras-chave - Phaseolus vulgaris L. Adubacao fosfatada. Nutriente. Germinacao. Vigor.

Características produtivas do trigo em função de fontes e doses de nitrogênio

Nitrogen fertilization is an important management practice in grasses and quite complex, due to several factors which influence it, such as climatic conditions, cropping systems and available levels and sources. This study aimed at evaluating the effect of topdressing nitrogen (N) sources and levels on the productive characteristics of wheat ( Triticum aestivum L.) grown after soybean, under no-till system. The experiment was conducted in an Oxisol, in Londrina, Parana State, Brazil. The experimental design was randomized blocks, in a 3x4 factorial scheme, with four replications. As topdressing N sources, urea, urea + urease inhibitor (NBPT) and polymer-coated urea were evaluated, in 2008, and urea, urea + urease inhibitor (NBPT) and ammonium sulfate, in 2009, in four doses (0.0 kg ha -1 , 40.0 kg ha -1 , 80.0 kg ha -1 and 120.0 kg ha -1 of N) applied 20 days after emergence. Plant height, lodging percentage, mass of 1,000 grains, grain yield and hectoliter mass were determined, and results showed that increased topdressing N levels promoted plants lodging, decreasing the mass of 1,000 grains, yield and hectoliter mass. The N sources did not affect the yield of the BRS Pardela cultivar grown after soybean.

Splitting of nitrogen fertilization on the yield performance of wheat genotypes

RESUMO - Objetivou-se avaliar o desempenho produtivo de genotipos de trigo com diferentes qualidades industriais em resposta as proporcoes de parcelamento da adubacao nitrogenada em cobertura. Foram avaliados seis genotipos de trigo, sendo estes: IPR 136 e LD 052114 (melhorador), IPR 130 e IPR 144 (pao) e BRS Louro e CD 105 (basico). A adubacao nitrogenada em cobertura foi realizada na dose fixa de 80 kg ha -1 na forma de ureia, com cinco formas de parcelamento como segue: P1- dose total aplicada no perfilhamento aos 20 DAE (dias apos a emergencia); P2 - ¼ no emborrachamento e o restante aos 20 DAE; P3 - ½ aos 20 DAE + ½ no emborrachamento; P4 - ¼ aos 20 DAE e o restante no emborrachamento e P5 - dose total de N aplicada no emborrachamento. As proporcoes de parcelamento da adubacao nitrogenada em cobertura nao afetaram o ciclo, o grau de acamamento, o peso hectolitrico (PH), a massa de 1.000 graos, o numero de espiguetas por espiga, o numero de graos por espigueta, o numero de graos por espiga, a massa de graos por espiga e o n° de espiga/m 2 . Os genotipos IPR 136 e LD 052114 apresentaram maiores rendimentos de graos quando o N foi aplicado em uma unica vez em P1 e P5, respectivamente. Para os genotipos BRS Louro, IPR 130 e CD 105 as diferentes epocas de adubacao nitrogenada nao afetaram a produtividade de graos. Na cultivar IPR 144, a adubacao nitrogenada em cobertura dos tratamentos P1, P2 e P5 favoreceu a produtividade de graos. Palavras-chave: Trigo. Cultivos de cobertura. Plantas. Efeito de Nitrogenio.

Épocas de tratamento de sementes no estabelecimento e desempenho produtivo da cultura da soja

The objective was to assess the early treatment effect of soybean seeds and pre-sowing with different combinations of chemicals on the establishment of plants and crop yield performance. The design was in randomized blocks in a 2x7 factorial arrangement, with two times for seed treatment and seven treatments (six chemical treatments and an untreated control). The treatments were: 1) fipronil + pyraclostrobin + thiophanate methyl; 2) imidacloprid + thiodicarb + carbendazin + thiram; 3) abamectin + thiamethoxam + fludioxonil + mefenoxam + thiabendazole; 4) carbendazin + thiram; 5) fludioxonil + mefenoxam + thiabendazole; 6) carboxin + thiram; and 7) untreated control (water only). The assessments were: seedling emergence, final stand, plant height and insertion of first pod, number of pods per plant, seeds per pod and per plant, thousand-seed weight and grain yield. Early treatment of soybean seeds (240 days prior to sowing) hinders the establishment of the crop, the thousand-seed weight and grain yield in relation to the pre-sowing treatment. Chemical treatments tested containing fungicides and insecticides associated favor the establishment of the crop, but do not alter the soybean yield performance.

Formas de ureia e doses de nitrogênio em cobertura na qualidade fisiológica de sementes de trigo

Besides increasing productivity, nitrogen fertilization may have positives effects on seed physiological quality. The objective of this study was to evaluate the effect of different forms and levels of urea in top dressing fertilization on the physiological quality of wheat seed genotypes. Seeds of three wheat genotypes (BRS 208, BRS Pardela and IWT 04008) were evaluated for four levels of nitrogen fertilization (0, 40, 80 and 120 kg.ha-1) in three forms of urea (conventional urea, urea with urease inhibitor and protected urea). The nitrogen fertilization was applied during tillering, 20 days after emergence. The seed nitrogen content, 1000 seed mass, germination and vigor (germination first count, cold test, seedling emergence in the field, dry weight of seedlings, accelerated aging and electrical conductivity) were evaluated. The IWT 04008 line and the cultivar BRS Pardela had seeds with a higher physiological quality than those of the cultivar BRS 208. The forms of urea and levels of nitrogen in topdressing did not affect seed physiological quality of the different wheat genotypes.

Plant density and mineral nitrogen fertilization influencing yield, yield components and concentration of oil and protein in soybean grains

There are few studies on the interaction between soybean plant density and nitrogen fertilization. This research aimed to assess the effect of mineral nitrogen associated to different plant densities on yield, yield components and oil and protein concentrations of soybean grains. Two experiments were conducted in the 2013/2014 and 2014/2015 growing seasons, with randomized complete block design, in a split plots scheme, with six replications. Four sowing densities (150, 300, 440 and 560 thousand viable seeds∙ha-1) were allocated in the plots, and two nitrogen levels (0 and 45 kg N∙ha-1, applied at V2, using ammonium sulfate) were allocated in the subplots.

Doses e épocas de aplicação de nitrogênio em cobertura na qualidade fisiológica de sementes de milho doce

The amount and timing of nitrogen application can favor seed quality, such as increasing protein content, which is an important constituent for embryo development. The objective of this study was to evaluate the physiological quality of sweet corn seeds collected from plants cultivated with different dosages and timings of nitrogen top-dressing applications. Seeds of the BR 400 variety (Super Sweet) were used obtained from plants submitted to dosages of 0, 40, 80 and 120kg ha-1 of N in two top-dressing applications (vegetative and reproductive stages). The weight of 100 grains, germination, first count of germination test, dry weight of normal seedlings from the germination test, seedling growth, cold test, accelerated aging, tetrazolium vigor and electric conductivity and emergency speed rate were determined. Data was submitted to an analysis of variance using the F-test at the 5% level and second degree regression analysis. The dosage and time of application of nitrogen top-dressing did not affect seed weight or the germination of sweet corn seeds. An increase of the N top-dressing dosage, applied in the vegetative stage reduced the length of the aerial part, the root and the whole seedling.

Maize Inoculation with Azospirillum brasilense Ab-V5 Cells Enriched with Exopolysaccharides and Polyhydroxybutyrate Results in High Productivity under Low N Fertilizer Input

Although Azospirillum strains used in commercial inoculant formulations presents diazotrophic activity, it has been reported that their ability to produce phytohormones plays a pivotal role in plant growth-promotion, leading to a general recommendation of its use in association with regular N-fertilizer doses. In addition, a high variability in the effectiveness of Azospirillum inoculants is still reported under field conditions, contributing to the adoption of the inoculation technology as an additional management practice rather than its use as an alternative practice to the use of chemical inputs in agriculture. To investigate whether the content of stress-resistance biopolymers would improve the viability and performance of Azospirillum inoculants when used as substitute of N-fertilizers, biomass of A. brasilense strain Ab-V5 enriched in exopolysaccharides (EPS) and polyhydroxybutirate (PHB) was produced using a new culture medium developed by factorial mixture design, and the effectiveness of resulting inoculants was evaluated under field conditions. The culture medium formulation extended the log phase of A. brasilense cultures, which presented higher cell counts and increased EPS and PHB contents than observed in the cultures grown in the OAB medium used as control. An inoculation trial with maize conducted under greenhouse conditions and using the biopolymers-enriched Ab-V5 cells demonstrated the importance of EPS and PHB to the long term bacterial viability in soil and to the effectiveness of inoculation. The effectiveness of liquid and peat inoculants prepared with Ab-V5 cells enriched with EPS and PHB was also evaluated under field conditions, using maize as target crop along different seasons, with the inoculants applied directly over seeds or at topdressing under limiting levels of N-fertilization. No additive effect on yield resulted from inoculation under high N fertilizer input, while inoculated plants grown under 80% reduction in N fertilizer showed yields at levels compared to fully fertilized plants, regardless the inoculation method. The presented data highlights the feasibility to partially substitute the N-fertilizer demand in non-legume crops using high-quality inoculant formulations, prepared with diazotrophic bacteria enriched with stress-resistance biopolymers that confer increased viability an effectiveness to the bacterial cells.

Aplicação foliar de aminoácidos e adubação nitrogenada de cobertura na cultura do milho safrinha

The objective of this study was to evaluate the foliar application of amino acids associated with the application of nitrogen as topdressing on yield performance and agronomic characteristics of corn, cultivated during the latter season. The experimental design was a randomized block design in a 4 x 4 factorial, with 4 repetitions. Four doses of nitrogen (0, 60, 120 and 180 kg ha-1) as urea were used and four doses of amino acids (0, 8, 16, and 24 L ha-1) were applied on leaves. The maize cultivar used was Pioneer 305 31H. The variables analysed were: leaf N content, plant height, ear height, stem diameter, ear length, number of kernel rows per ear, number of kernels per row, number of grains per spike, weight of 100 grains and yield. The amino acids did not alter the analysed variables. Nitrogen increased linearly the variables plant height, height of insertion of ear, number of grains per ear and number of kernels per row. The length of spike, thousand grain weight and grain yield response to nitrogen obtained under maximum doses of 135.3, 157 and 149.5 kg ha-1, respectively.