Influência dos sistemas de rotação e sucessão de culturas sobre a supressão de plantas daninhas

Abstract

Weed management stand up among many current difficulties in agriculture, which reflects the production systems adopted and the great selection pressure imposed due to the almost exclusive use of chemical management as a control strategy. At the same time, the adoption of cover crops compete with commodities for the soil use and may require a longer period of time than just one year of use to express all its advantages in the production system. In this sense, this work aimed to evaluate the influence of succession and crop rotation systems on the occurrence of weeds and to assess the potential of cover crops used in the 2nd summer crop to suppress the weed community. Experiment report four crop production systems in the 2020/21 and 21/22 cropping season, being two succession and two rotation systems. In the second summer crop, six different management strategies are carried out, two with commercial crop with grain vies and four with cover crops, resulting in 24 productive arrangements. The adopted design was randomized blocks with three repetitions in subdivided plots. Based on the results it was possible to see that in the corn harvest + grain and cover crops system, the number of weed species increased in the second year of harvest, while the soybean harvest + grain and cover crops system and the rotation system (system 3) showed a reduction of weed species in the second season. In rotation system 4, there was an increase in the occurrence of weeds, except where there lab lab. The lab lab, braquiária and milheto cover plants reduced weeds in system 2 and 3. The weeds with the highest importance value index in all systems were E. heterophylla, Conyza spp., B. pilosa and S. rhombifolia.