Densidade de plantio e poda da parte aérea na partição de massa seca de plantas de batata em hidroponia

Abstract

Hydroponic system is an important improvement of the potato production process of tuber seeds. There is no enough information about management techniques of hydroponically cultivated potato. A main problem of this production system is the excessive shoot growth, which results in a low propagation rate. Planting density and pruning may change the relationship between shoot and tuber growth, affecting dry matter partitioning. The objective of this work was to study the effect of planting density and pruning in the dry matter partitioning of hydroponically cultivated potato plants to reduce shoot growth an increase tuber dry matter accumulation. One experiment was carried out to study the effect of planting density in the growth and dry matter partitioning of potato plants during spring 2004. Planting densities of 25, 44, 100 and 400 hills.m-2 were evaluated. Another experiment was carried out to study the effect of leaf area restriction with pruning in the dry matter partitioning during fall and spring 2005 growing seasons. The treatments were pruning aerial parts of plants at 10, 20, and 30 cm height and control (with no pruning). Planting density and pruning affected dry matter partitioning of hydroponically cultivated potato plants. Planting density of 100 hills.m-2 results in the highest plant growth and tuber fraction production. This density should be used to the production of potato in hydroponic system. Increasing hill density improves tuber number yield without reducing tuber dry matter production. Pruning plants at 30 cm high is a management practice that can be used to restrict shoot growth of potato plants grown hydroponically, with small yield reduction during spring.