Luiz Fernando Favarato

COMPOSIÇÃO MINERAL DE GRÃOS DE TRIGO SUBMETIDOS A DOSES DE SULFATO DE AMÔNIO E TRINEXAPAC-ETIL

Grain mineral composition is important for the establishment of appropriate fertilizer levels, as well as to define the nutritional quality of food and physiological quality of seeds. The objective of this study was to evaluate the effect of ammonium sulfate (AS) and trinexapac-ethyl rates on mineral composition of wheat grains ( Triticum aestivum L.) cv. Pioneiro. The experiment was carried out in Vicosa, Minas Gerais State, Brazil, from June to October 2006. The treatments consisted of five AS rates (150 kg ha -1 , 300 kg ha -1 , 450 kg ha -1 , 600 kg ha -1 , and 750 kg ha -1 ) combined with four trinexapac-ethyl rates (0 g ha -1 , 62.5 g ha -1 , 125 g ha -1 , and 187.5 g ha -1 ). The experiment was arranged in a randomized block design with four replications. AS rates increased the concentrations of total-N (protein), Ca, S, Cu, and Zn and decreased the concentrations of P, K, and Mn (at AS rates above 457 kg ha -1 ). The Mg and Fe concentrations were not influenced by AS rates. Trinexapac-ethyl increased total-N, P, and Mn; reduced Ca; and had no influence on the concentrations of K, S, Cu, Zn, Mg, and Fe. It can be concluded that AS application improves the nutritional quality of grains, while the use of the growth retardant trinexapac-ethyl has no influence on its mineral composition. KEY-WORDS: Triticum aestivum L.; nutrition; growth retardant.

EEFEITOS MÚLTIPLOS DA COBERTURA MORTA DO SOLO EM CULTIVO ORGÂNICO DE CENOURA

O objetivo do trabalho foi avaliar os efeitos multifuncionais de cinco tipos de residuos orgânicos,xa0como cobertura morta de canteiros de cenoura, no sistema orgânico de producao. Os tratamentos foram:xa01-Testemunha; 2-Pseudocaule de bananeira; 3-Palha de cafe; 4-Capim Cameron picado; 5-Casca de arrozxa0e 6-Bagaco de cana triturado. Foi utilizado o delineamento de blocos casualizados com quatro repeticoes sendo avaliados o gasto com mao de obra, o numero total de plantas e massa da materia fresca de plantasxa0daninhas, numero total de raizes, produtividade, peso medio de raiz e percentual de raizes rachadas e bifurcadas. Nao se observou aumento da materia orgânica do solo com a utilizacao dos residuos, devidoxa0ao curto ciclo cultural da cenoura. Residuos ricos em potassio, como a palha de cafe e pseudocaule de bananeira, confirmaram potencial de fornecimento do elemento ao solo, reduzindo perdas durante oxa0ciclo cultural. As quantidades de plantas daninhas remanescentes foram reduzidas pelas coberturas, com consequente reducao significativa no gasto e no valor financeiro da mao de obra para as duas operacoesxa0de capina manual dos canteiros.

Qualitative attributes and postharvest conservation of green ears of maize grown on different cover crops in organic no-till system

Postharvest quality of sweet maize varies depending on the type of seed, soil, quality of fertilizer, climatic conditions, and stage of maturation. This study aimed to evaluate the post-harvest quality and shelf life of green ears of maize grown on three soil covers in organic no-till sytem. The study was conducted in the municipality of Domingos Martins, ES (20° 2216.91 S and 41° 03 41.83 W). The experiment was arranged in a randomized block design with six replications and five treatments, consisting of three cover crops in organic no-till system: black-oat straw, white lupin, oat/lupin intercrop and two systems, organic and conventional, without straw. Maize double hybrid AG-1051 was sown in a spacing of 1.00 x 0.20 m. The variables evaluated included relative percentage of grain, straw and cob, pH, titratable acidity, soluble solids, grain moisture and shelf life. The use of different straws in the organic no-till system does not influence the postharvest quality of green ears. Ears packed in polystyrene trays with plastic film are suitable for marketing until the fifth day of storage at room temperature.