Efeito de diversas espécies de cobertura morta sobre o controle de plantas daninhas da cultura do milho ( Zea mays )

Abstract

Researches of many south american countries point the zero tillage system of crop production for little farmers as a responsible factor for best soil and water conseivation, less costs of production and best profits to improve the rural way of life. The treatements usually include the application of herbicides. To find agricultura( systems that allow zero tillage without hercicide or with reducsed usage has been considered a challenge by the researchers. This experiment was carried out in order to evaluate the effects of different mulches on the control of unwished plants in maize crop (Zea mays). Plants such as sunhemp (Crota/aria Juncea), millet (Pennisetum americanum) and sunflower (Helianthus annus L.) cv. Stanzuela and V 2.000 were grown in 100 m' areas. The sowing was made at the second April fortnight and, after sixty days, the zero tillage system with maize was established by using a manual planting machine. Just after, the plants grown in the plots were manually cut and used as mulch. Toe soil fertility was corrected according to the laboratorial analyses and the plant population adopted was around 60.000 plants per hectare. No weed control was made. At the maize flowering, the seed weeds grown in the plots were collected by using two samples of 1 m' plot (two replications). The plant material was dried till coustant weight. Statistical analyses obtained from the data indicated the millet mulch as the best treatment to the weed control.