Tiago Zoz

Crescimento de Stylosanthes cv. Campo Grande em diferentes níveis de densidade de um Latossolo Vermelho

O Stylosanthes spp. cv. Campo Grande e uma leguminosa recomendada para a recuperacao de areas de pastagens degradadas, entretanto sao escassas as informacoes sobre seu desenvolvimento em solos compactados. Assim, objetivou-se com o presente trabalho avaliar o desenvolvimento do Stylosanthes cv. Campo Grande em diferentes niveis de densidade de um Latossolo Vermelho eutroferrico (LVef). O experimento foi desenvolvido no periodo entre setembro de 2007 e marco de 2008, em cultivo protegido. O delineamento experimental utilizado foi inteiramente casualizado. Os tratamentos consistiram de cinco niveis de compactacao do solo em sub-superficie (1,0; 1,2; 1,4; 1,6 e 1,8 Mg m-3) com quatro repeticoes. As unidades experimentais foram compostas por vasos montados a partir de aneis de PVC sobrepostos. No solo estudado (LVef) o maximo crescimento do Stylosanthes cv. Campo Grande ocorre com a densidade de solo em torno de 1,27 Mg m-3; e densidades de solo acima de 1,00 Mg m-3 limitam o desenvolvimento radicular desta leguminosa.

Plant density and nitrogen fertilization in Swiss chard

An experiment was conducted to evaluate the effect of plant spacing and nitrogen fertilization on Swiss chards yield, from September to November 2009. The experimental design was of randomized blocks in split plot with four replications. In the plots were allocated the two plant spacings (0.30 and 0.50 m) and in the subplots the five doses of nitrogen (0, 40, 80, 120 and 160 kg ha-1). The crop was harvested 90 days after transplanting. The plant spacing of 0.50 m provided increased production of total fresh weight of shoot (961.7 g plant-1) and marketable (873.1 g plant-1). However, the highest total yield (77.8 t ha-1) and marketable (64.5 t ha-1) was achieved with the smaller spacing between plants (0.30 m). The N rates applied in coverage until 160 kg ha-1 increased in a linear form the total and marketable production of fresh mass of shoots, the total and marketable yield, the N content and the N accumulation in the shoots of Swiss chard plants on the evaluated plant spacings.

Effect of boron and zinc fertilization on white oats grown in soil with average content of these nutrients

ABSTRACT - The objective of this study was to evaluate the effect of fertilization with zinc or boron on the growthand dry matter production, nutritional value and accumulation of nutrients in white oats. The study comprised two experimentsconducted in glasshouses, the first consisting of the application of four doses of zinc (0, 0.2, 0.4 and 0.6 mg/dm 3 ) in the formof zinc sulphate (20% Zn), and the second consisting of the application of four doses of boron (0, 0.2, 0.4 and 0.6 mg/dm 3 )in the form of Borax (11% B). The experimental design in each case was a randomized block design, with five replicates.Fertilization with zinc and boron increased the growth of white oats, but had no significant effect on the nutritional valueof the forage. Higher levels of absorption and accumulation of nutrients in plant tissues were observed following the applicationof boron and zinc at rates of up to 0.60 mg/dm 3 of soil.Key Words: Avena sativa , crude protein, dry matter Revista Brasileira de Zootecnia

Response of wheat to foliar application of zinc

Wheat is grown in Brazil, mostly in no-till, a system in which the zinc can become potentially deficient, due to excessive application of acidity corrective and phosphate fertilizers in surface and, or at shallow depths. This study aimed to evaluate the effect of foliar application of zinc in agronomic characteristics and yield of wheat. The experimental design was randomized blocks with five replications. Treatments consisted of four doses of zinc (0, 54, 108 and 216g ha-1 Zn), divided into two foliar applications, the first at tillering (18 days after plant emergence) and the second at the boot stage (65 days after emergence). Foliar application of zinc increased the number of fertile tillers and yield of wheat, however, have little effect on the agronomic characteristics of no-tilled crop with high nutrient content in soil.