Integration mulches with atrazine for weed management in corn

Abstract

The use of cover crops can contribute to the reduction of the dose required for weed control. The aim of this work was to assess the growth of weeds and productivity of corn from different degrees of black oat cover and velvet bean and atrazine doses. Two experiments were conducted in the experimental area, both was conducted in randomized blocks in a split plot design with four replications. In the main plots were randomized, four straw levels (0, 0.75, 1.5 and 3 times the amount originally produced) oat (Exp 1) or velvet bean (Exp 2). In the subplots were randomized to four doses of atrazine (0, 2100, 4200 and 8400 g ha -1 ). It was evaluated the weed density and crop yield. The utilization of straw species coverage on the ground, even at high levels, was not enough to exercise total control of weeds. Atrazine was not effective in weed control only in the treatment with 2100 g ha -1 of the herbicide and no velvet bean straw on the ground, but the straw of this species realized suppressive effect, supplementing the effect of the herbicidal dose. Levels in 2775 and 5550 kg ha -1 of velvet bean straw reduce the productivity of corn. Integrating the use of oat or velvet bean straw with low dose of atrazine (2100 g ai ha -1 ), results in effective weed control systems and more suitable cropping systems in the environmental aspect, both by reducing the use of herbicides as taking advantage of the benefits of no-till system. Palavras-chave:Avena strigosa, manejo integrado de plantas daninhas, Stilozobium aterrimum

The straw presence preceding soybean crop increases the persistence of residual herbicides

“…However, studies reinforce the importance of integrating the use of mulching with other weed management tools. Several studies highlight the existence of a complementary effect between the use of herbicides and mulching (Marchesan et al, 2016). To achieve this integrated control system, cover crops need to produce sufficient amount of straw covering the soil, which allow the maximization of its physical and allelopathic effects (Trezzi et al, 2016) combined with the use of herbicides that are able to migrate from the straw to the soil (Carbonari et al, 2016), both favoring weed suppression and control.…”

Interference Periods of Weeds in Maize in No-Tillage and Conventional Systems at High Altitudes

“…One of the important alternative strategies for weed management and soil protection adopted in agricultural systems in southern Brazil is the practice of direct seeding (no-tillage system) with the maintenance of straw on the soil surface (Altieri et al, 2011). Black oats (Avena strigosa) are the most widely used mulch in production systems that precede maize cultivation in southern Brazil (Silva et al, 2006;Marchesan et al, 2016). In addition to the abundant root system and high production of dry matter for soil coverage, black oats also improve the physical, chemical, and biological properties of the soil, in addition to having slow decomposition (high C/N ratio) and high lignin content (Rizzardi and Silva, 2006).…”

Carryover de herbicidas utilizados no controle de soqueiras do algodoeiro sobre o milho cultivado em sucessão

“…A persistência de um herbicida pode ser definida como a capacidade que ele tem para manter a integridade de sua molécula e suas características físicas, químicas e biocidas no ambiente através do qual ele é transportado e distribuído após a sua liberação (MARCHESAN et al 2016). Esta persistência depende de características físico-químicas da molécula, bem como de características inerentes ao solo, como a granulometria, o pH, a capacidade tampão, a mineralogia, o teor de matéria orgânica e a atividade microbiana, além das condições climáticas (GONÇALVES et al 2018).…”