Efeitos alelopáticos de diferentes extratos de plantas de cobertura sob o desenvolvimento inicial de feijão, soja e milho

Abstract

With the population growth, it is sought to produce food each time in greater quantity, in even smaller spaces. Thus, the national productive system has been continuously modernizing over time. It can be considered a landmark in the history of Brazilian agriculture, as one of its main premises is the use of vegetation cover on the soil. It is in this bias that the present work had the intention of evaluating possible allelopathic effects of four different cover crops, in the germination of Beans (Phaseolus vulgaris), Soja (Glycine max) and Corn (Zea mays). Chicory (Cichorium intybus), Buckwheat (Fagopyrum tataricum), Black Oats (Avena strigosa) and Quinoa (Chenopodium quinoa). The seeds were seeded in Germitest papers, which were soaked by plant extracts. The concentration of these extracts was 200 g of plant dry mass to 2 L of distilled H20. After sowing, the germitest papers were rolled into groups of 4 (each with 4 replicates of a given treatment) packed in a plastic bag, and brought to the germinator at 27.9°C for 8 days. On the 5th day, the first evaluation was carried out, determining the average percentage of germination. On the 8th day, the presence of normal, abnormal and dead seedlings was evaluated. In a second moment, 10 abnormal plants of each repetition were selected to make the means of seedling length and green mass. These plants were submitted to a greenhouse for 48 hours at a temperature of 650C, after which the last evaluation, which was the dry mass, was carried out. Quinoa had a more intense allelopathic effect on the cultures. Among them the one that was most sensitive to the effects, was the one of the beans. Not being recommended the use of it, as well as black oats as predecessors to bean culture.