Atividade alelopática das coberturas de aveia-preta, quinoa e trigo-mourisco no desenvolvimento inicial das culturas de milho e soja

Abstract

The correct choice of crops to cover the soil in the no-tillage system is extremely important. Knowing the species and their characteristics can define what will be the management strategies and the performance of subsequent crops. Among some premises for the use of cover crops are protecting the soil from erosion, guaranteeing nutrient cycling, reducing weed infestation and improving the performance of the crops that will be implanted. Within this context, some plants produce allelochemicals, substances responsible for contributing or inhibiting the germination, growth or development of other plants. The objective was to evaluate whether there is allelopathic activity of black oat straw (Avena strigosa), quinoa (Chenopodium quinoa) and buckwheat (Fagopyrum esculentum) on soybean and corn crops. Two experiments were carried out in pots in a greenhouse, in a completely randomized design (DIC), treatment was carried out: black oat, quinoa, buckwheat and uncovered soil (control) cover, each treatment with four replications. The emergence speed index (IVE), percentage of germination, plant height, number of leaves, stem diameter, dry root weight and dry weight of the aerial part of summer crops were evaluated. For the corn crop, black oat coverage presented the highest allelopathic potential, its IVE, number of emerged plants, growth of aerial part and roots, without its use being necessary without a minimum interval of days between its desiccation and planting. Of corn. Still for corn, both the coverage with quinoa and secondary buckwheat had good results, being superior to the bare soil. In relation to the soybean crop, there were no proportional allelopathic effects of the cover crops on it, but the superiority of the coverages in relation to the control (bare soil) was noted, demonstrating the importance of using cover crops in the system and that all species can be used.