Alcides Reis Condé

Conservação pós-colheita de alface cultivada com composto orgânico

O objetivo deste trabalho foi avaliar o efeito da adubacao com composto orgânico, na presenca e na ausencia de adubacao mineral padrao, na conservacao pos-colheita das plantas de alface cultivar Baba. O composto orgânico foi aplicado nas doses de 0,0, 22,8, 45,6, 68,4 e 91,2 t/ha de materia seca. Foram avaliadas a perda de materia fresca em condicoes de ambiente e a degradacao da clorofila em câmara fria (4 o C) ate 84 horas e 12 dias, respectivamente, apos colheita. A aplicacao de doses crescentes de composto orgânico reduziu a perda de materia fresca apos a colheita em ate 7%; os teores de clorofila decresceram durante o armazenamento, em plantas adubadas com 45,6 e 91,2 t/ha de composto orgânico e adubo mineral, atingindo cerca de 0,3 mg/g de tecido fresco. A aplicacao conjunta de adubo mineral e composto acelerou a senescencia de alfaces mantidas em câmara fria, mas o cultivo com composto orgânico reduziu a perda de materia fresca em condicoes de ambiente.

Lixiviação e inativação do metribuzin em dois tipos de solos

Laboratory and greenhouse experiments were made to evaluate the leaching and the inactivation of the metribuzin in clay loam and sand clay loam soils. The clay loam soil was a dark, red latosol with 2,8% organic matter and the sand clay loam soil was a reddish-yellow podzol with 2,17% organic matter. Leaching of metribuzin was studied in the laboratory in colums of 5, 10 and 15 cm high, 7.5 cm diameter, filled with soil. Watermelon cotiledon discs were used to measure the metribuzin leached. The inactivation of metribuzin was estudied in a greenhouse using doses of 0, 50, 80, 110, 140, 170 and 200 g/ha on the two soils, and 0, 4, 6, 8, 10, 12 and 16 g/ha were used for testing in sand. The test plants were cucumber that weighed after 14 days growth. Additional information is needed to explain why the clay loam soil inactivates metribuzin more than the sand clay loam soil and clarify the roles.

Controle químico de plantas daninhas na semeadura direta de tomate (Lycopersicon esculentum Mill.)

Three assays were carried out to evaluate the effectiveness of several herbicides on direct seeded tomato. The compounds metribuzin, napropamide, chloramben, diphenamid, pebulate and trifluralin aplied separatly, at the dosage of .35; 3.40; 2.50; 2.00; 3.60 and .67 kg/ha respectively, and combined each one with metribuzin at the same dose ge were evaluated in two assays, one at Vicosa, MG and the other at Domingos Martins, ES. One third assay was carried out at Vicosa, MG to evaluate the effectiveness of chloramben, napropamide, diphenamid and metr ibuzin at the dose of 3.40; 3.00; 5.00 and .70 kg/ha respectively, and pebulate at the dose of 4.32 and 1.76 kg/ha applied separated and combined with pebulate at mentioned dosages. All compounds showed some control of weeds, although the efficiency of each product was weed species dependant. Only pebulate was efficient on Cyperus rotundus control. Bachiaria plantaginea and Digitaria sanguinalis were better controled by chloramben, napropamide, diphenamid and trifluralin. Metribuzin gave excelent control of Bidens pilosa and Galinsoga parviflora. The mixtures of metr ibuzin or pebula te wi th each herbicide sudied increased the efficience of control and the number of species controled. All compounds were tolerated by the tomato plants. No visible injury were observed at the doses studied.