Supressão de plantas espontâneas com Crotalaria ochroleuca sob os sistemas de tratamento biodinâmico, convencional e orgânico

Abstract

One of the main problems faced in annual crops currently is the presence of weeds and the main control method is the use of herbicides, which cause damage to the environment and increase the farmer's production costs. The use of cover crops as sunn hemp appears as an alternative for the integrated management of weeds. The aim of the work was to evaluate the effects of slenderleaf rattlebox or rattlepod (Crotalaria ochroleuca) on the suppression of weeds in different cultivation systems. The field experiment was implemented on 12/30/2022 in a randomized block experimental design, consisting of 6 blocks and 4 treatments: biodynamic, organic, conventional and control. Soil seed bank assessments were carried out with soil sampling and subsequent incubation in a BOD type chamber to determine the number of readily germinable seeds and calculate abundance, richness, proportion and Shannon diversity index. Other variables evaluated were the mass production of aerial parts of sunn hemp and weeds at the end of the cycle. The most frequent weeds were gray everlasting (Gamochaeta coarctata) and spreading liverseed grass (Urochloa decumbens). The organic treatment showed a higher richness value and Shannon diversity index in the soil seed bank. There was a significant difference among treatments on the aboveground phytomass of sun hemp, with conventional cultivation showing the highest production at 20.882 kg ha-1. Sun hemp exhibited more than twice the dry phytomass of its aboveground parts (20.882 kg ha-1) when compared to the dry phytomass of aboveground parts of spontaneous plants (7.566 kg ha-1), highlighting the suppressive effect. The different treatments did not have an influence on the aboveground phytomass of spontaneous plants.