CRESCIMENTO DO FEIJOEIRO EM RESPOSTA AO EFEITO RESIDUAL DO POTÁSSIO EM SUCESSÃO COM A CULTURA DO MILHO

Abstract

Some nutrients are of great importance for the bean crop, potassium has several functions in this crop, being able to trigger enzymatic systems, which promote an important role in the process of photosynthesis. The deficiency of this nutrient entails in plants with slow growth, unstable roots and stems with greater possibilities of being attacked by some diseases. The residual effect of Potassium in the soil varies according to the amount that the crops can assimilate, in addition to how much is lost due to leaching. The succession planting is a technique widely used by farmers in the state of Paraíba, based on that, the present study aimed to evaluate the residual effect of potassium in the bean crop, after the planting of maize. The experiment was carried out in the experimental area belonging to the Departamento de fitotecnia e Ciências Ambientais – CCA – Campus II of the Universidade Federal da Paraíba, located in the city of Areia-Paraíba. The experimental area was composed of 4 replicates, with 10 treatments previously randomized in the maize crop, each treatment with 4 grooves, and 2 application of K (sowing, V5 stage of maize). The following variables were evaluated: Plant height, stem diameter, number of nodes and number of trifoliate leaves. At the doses of 50 and 100 kg ha-1, the height of the bean had a decrease, but, with the increase of the dose, an increase occurred in the height, this shows that the doses in greater quantity, can promote in subsequent plantings, residual effects. In relation to the diameter, it was found a influence in the periods potassium fertilizer application, and verified a significant effect in the quadratic model, it was observed in the number of nodes that he higher the potassium doses, the growth curve increased in the doses with contents of 200kg ha -1, and the number of trifoliate leaves was influenced by the periods of potassium application. For plant height, diameter, number of nodes and number of leaves, the dose of 200 kg ha -1 was better in the V5 stage compared to the sowing. Thus, fertilization in the V5 stage in maize crop promotes residual effects of potassium to the BRS cultivar, notable compared to fertilization during sowing in succession planting.