Condicionamento osmótico de sementes e potencial alelopático de resíduos de girassol

Abstract

The aim of this study was to evaluate the effect of osmotic conditioning on seedling emergence and performance of sunflower plants (Helianthus annus L) and the influence of sunflower residues in cultivation of oilseed radish (Raphanus sativus L.). Also wereevaluated the action of aqueous extracts of sunflower on differents seeds. For this, three batches of seeds sunflower cultivar Catissol were treated, or not, with the osmotic conditioning solution of polyethylene glycol to -2.0 MPa and evaluated seedling emergence, plant development, as well as productivity and sunflower seeds quality. Thereafter was planted oilseed radish in the area with and without sunflower residues, and evaluated the plant growth, yield and quality of radish seeds produced in both areas. The results showed that the osmotic conditioning favored the seedling survival, seed production per plant and dry weight of leaves and shoots of plants from seed physiological quality lower. The sunflower residues reduced the seed production per plant and improve the vigor of the radish seeds. The aqueous extract of sunflower leaves collected at 60 days after sowing to 10% reduzed the germination of lettuce seeds, rope and pick black for causing water restriction beyond the phytotoxic effect.