Suscetibilidade à podridão negra e produtividade de brócolis em função de doses de nitrogênio e potássio

The purpose of this study was to investigate the influence of potassium and nitrogen on the severity of black rot and yield of head. The experiment was carried out in split plots with factorial subplots, in randomized blocks with four replications. In the plots we assessed the influence of inoculation (injured plants with distilled water and inoculated with Xanthomonas campestris pv. campestris) and in the subplots we evaluated the 4 x 4 factorial, potassium doses (0, 275, 550 and 825 kg ha-1) and nitrogen (0, 150, 300 and 450 kg ha-1). The hybrid Broccoli BRO68 was inoculated using the toothpick method at 64 days after sowing. We observed that potassium in the plant reduced the disease, but nitrogen increased disease. We estimated that the highest levels of potassum in the plant reduced the severity of the disease but lack or excess of nitrogen increased disease severity. The highest production of broccoli inflorescence was obtained at doses from 541 to 751 kg ha-1 of K2O and 286 to 328 kg ha-1 of N. However, when considering a balanced fertilization to obtain higher yield and size of inflorescences and greater resistance to black rot, the ideal doses are 283 kg ha-1 of N and 550 kg ha-1 of K2O.

Interação de genótipos de milho vs locais, anos e épocas de semeadura

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Utilização de maturadores para antecipação da colheita do milho

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Caracterização das formas juvenis e adultas dos camarões-rosa Farfantepenaeus brasiliensis (Latrelle, 1917) e F. paulensis (Perez-Farfante, 1967) (Decapoda: Penaeidae) por meio de técnicas moleculares e morfologia comparativa

Pós-graduação em Ciências Biológicas (Zoologia) - IBB

Arranjo de plantas, características agronômicas e produtividade de soja

Pós-graduação em Agronomia (Agricultura) - FCA

Efeito da cobertura do solo com palhiço de cana-de-açúcar na emergência de monocotiledôneas infestantes em campo

Pós-graduação em Agronomia (Agricultura) - FCA

Produtividade, qualidade fisiológica e composição química de sementes de crambe em diferentes doses de fósforo

The crambe is a brassica with high content of oil used for biodiesel production and that has aroused interest in the short cycle and low production cost. However, there are doubts about their response to phosphated fertilization. The objective of this study was to evaluate the effect of different doses of phosphorus on yield, physiological quality, chemical composition and oil content of crambe seeds. The treatments consisted of five doses of phosphorus (0, 25, 50, 75 and 100 kg ha(-1)) applied at sowing. There was no effect of phosphorus on mineral composition and oil content of the seeds of crambe that showed the following averages: 30.11 N, 7.46 P, 7.35 K, Ca 10.06, 6.58 mg and 8.98 g kg(-1) S; 36.25 Cu, Fe 169.40, 36.75 Mn 73.60 mg kg(-1) Zn and 30.22% oil. It was concluded that the productivity of crambe increases with phosphorus rates of up to 100 kg ha(-1), but its use does not affect the survival rate of plants, dry mass, the mass of thousand seeds, the physiological quality, chemical composition and oil content of the seed.

Formação de mudas de alface em bandejas preenchidas com diferentes substratos

This study was conducted in the Department of Horticulture and Experimentation at the University Jose do Rosario Vellano (UNIFENAS) in Alfenas-MG, Brasil in order to evaluate the formation of lettuce seedlings in trays filled with different substrates. The materials used to compose the substrates were pig bed base with wood shavings (M), pig bed with base coffee straw (C), earthworm humus (H) and commercial substrates Nutriorg (R) and Plantmax (R) The use of these pure substrates and various mixtures permitted the formation of 18 substrates that constituted the treatments. The experimental design was a completely randomized design with three replications. The lettuce seedlings were formed with the lettuce cultivar Regina. The seeds were sown in trays with 128 cells filled with the substrates under study. Each experimental unit was compost of 64 cells. The conduct of the experiment was within a protective structure of 85 m 2, model chapel with transparent plastic cover 100 microns thickness, additives against ultraviolet rays. After 30 days of sowing, ten seedlings were harvested randomly within each experimental unit for evaluating the number of leaves and the plant height. It was also evaluated the fresh and dry mass of aerial part and fresh and dry mass of root. It was concluded that the substrate T1 - M met the best features for the formation of lettuce seedlings in trays of 128 cells.

Heavy metals in cowpea (Vigna unguiculata L.) after tannery sludge compost amendment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Adubação com KCl revestido na cultura do milho no Cerrado

The use of coated potassium chloride can provide greater absorption of potassium resulting in the alteration of leaf contents, production components and grain yield. The objective of this study was to evaluate the effect of potassium doses using potassium chloride conventional or coated by polymer, in the corn crop under conditions of brazilian Savanna with low altitude. The experiment was conducted in Selviria, MS, Brazil, in a clayey Oxisol. The treatments consisted of four doses of K2O (0, 40, 80 and 120 kg ha(-1)), applied at sowing, and two sources: potassium chloride and potassium chloride coated by polymers. A randomized block design with eight treatments and four replications was used. The coated KCl is not efficient under the soil and climatic conditions studied, because it provided results similar to the conventional KCl for the K foliar content, crop components and grain yield of irrigated corn. The increment of K2O doses influenced positively the K and chlorophyll leaf contents, plant and spike insertion height and the number of rows and grains per spike. The maximum mean yield obtained was with 83.5 kg ha(-1) of K2O.

WHEAT NITROGEN FERTILIZATION UNDER NO TILL ON THE LOW ALTITUDE BRAZILIAN CERRADO

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estimativa da produtividade de trigo em função da adubação nitrogenada utilizando modelagem neuro fuzzy

Currently new techniques for data processing, such as neural networks, fuzzy logic and hybrid systems are used to develop predictive models of complex systems and to estimate the desired parameters. In this article the use of an adaptive neuro fuzzy inference system was investigated to estimate the productivity of wheat, using a database of combination of the following treatments: five N doses (0, 50, 100, 150 and 200 kg ha(-1)), three sources (Entec, ammonium sulfate and urea), two application times of N (at sowing or at side-dressing) and two wheat cultivars (IAC 370 and E21), that were evaluated during two years in Selviria, Mato Grosso do Sul, Brazil. Through the input and output data, the system of adaptive neuro fuzzy inference learns, and then can estimate a new value of wheat yield with different N doses. The productivity prediciton error of wheat in function of five N doses, using a neuro fuzzy system, was smaller than that one obtained with a quadratic approximation. The results show that the neuro fuzzy system is a viable prediction model for estimating the wheat yield in function of N doses.

Estresse hídrico induzido por soluções de peg e de nacl na germinação de sementes de nabiça e fedegoso

The plants are subject to the conditions of multiple stresses, such as water and salt stress, which limit their development and their chances of survival. Aware of the factors that control seed germination can generate support for management strategies of weed species. The objective of this study was to evaluate the possible effects of water stress caused by PEG and NaCl solutions on germination of wild Raphanus raphanistrum and Senna obtusifolia seeds. The seeding was done with four repetitions of 50 seeds on moistened paper with solutions of polyethylene glycol (PEG 6000) and NaCl at osmotic potentials of 0.0, -0.2, -0.4 and -0.8 MPa. The germination test was conducted at 25 degrees C in the presence of light, evaluating the first test score to seven days after sowing, and weekly, germination (normal seedlings) until 35 days; it was also calculated the index germination rate. The results allowed the conclusion that water stress by PEG causes a greater reduction in force, speed of germination and accumulated germination of seeds of Raphanus raphanistrum and Senna obtusifolia seeds. The Senna obtusifolia was more tolerant to water stress.

Cover crops affecting levels of ammonium and nitrate in the soil and upland rice development

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estimativa da necessidade de nitrogênio em cobertura no feijoeiro IAC Alvorada com clorofilômetro portátil

The aims of this study was evaluated the efficiency of nitrogen sufficiency index (NSI) calculated with base on the measures relative chlorophyll index (RCI) leaves, measured with portable chlorophyll meter, as an indicator of time of sidedressing N fertilization and verify which value of NSI (90% and 95%) is the most appropriate to indicate the moment of N fertilization on common bean cultivar IAC Alvorada. An experiment with five N managements (M1: 200 kg ha(-1) N (40 kg at sowing + 80 kg at 15 days after emergency (DAE) + 80 kg 30 DAE); M2: 100 kg ha(-1) N (20 kg at sowing + 40 kg at 15 DAE + 40 kg at 30 DAE); M3: 20 kg ha(-1) N at sowing + 30 kg ha(-1) when chlorophyll meter readings indicated NSI < 95%; M4: 20 kg ha(-1) N at sowing + 30 kg N ha(-1) N when chlorophyll meter readings indicated NSI <90% and, M5: control (without N application)) and four replications was carried out in the rainy and dry growing seasons of the agricultural year 2009/10, in Botucatu, Sao Paulo State, Brazil. The variables RCI, aboveground dry matter, leaf N concentration, yield components, grain yield, and N use efficiency were evaluated. The NSI of 90%, calculated based on monitoring of RCI in common bean leaves with chlorophyll meter, was more effective than 95% to define need for N sidedressing in common bean cultivar IAC Alvorada, reducing the N application and improving the use efficiency of applied N.