Dinâmica populacional de plantas daninhas em cultivo de milho-verde nos sistemas orgânico e tradicional

Abstract

This work aimed to study the weed population dynamics in green corn cultivation under the organic and traditional systems. This study was developed during the growing season of 2003/04 using the no-till system on straw. Treatments consisted of four doses and nutrient sources : SA - no fertilization; AM1 - mineral fertilization at 150 kg ha -1 of 8-28-16 + 50 kg of N ha -1 in cover; AM2 - mineral fertilization at 300 kg ha -1 of 8-28-16 + 100 kg of N ha -1 in cover and AO - fertilization with organic content at 40 m 3 ha -1 applied over straw at 10 days after planting), combined with two corn cultivars (UFVM 100-Nativo and AG 1051). For the phytosociological study, the weeds were evaluated when reaching the stage of four complete leaves, before post-emergence herbicide application and first weed cut. The species Jaegeria hirta, Artemisia verlotorum, Bidens pilosa, Cyperus rotundus and Ipomoea grandifolia were the most frequent in the area. Bidens pilosa showed higher relative importance, regardless of the green corn growth system. The management practices used for green corn cultivation under the organic system were efficient in weed management when soil cover with Avena strigosa straw was adopted.