Superação de dormência em sementes de três espécies de Ipomoea

Abstract

The knowledge of the method of overcoming dormancy for each species helps in identification of dormancy type and to outline the most appropriate management strategies for effective control measures. The species of the genus Ipomoea are widely distributed in the Brazilian states, the most commonly found in soybean crops in the Southwest region of Paraná are I. purpurea, I. indivisa and I. grandifolia. In this research the aim was select methods of overcoming seed dormancy for species Ipomoea indivisa, I. grandifolia and I. purpurea, and determine how these methods influence the kinetic germination of these species. The treatments consisted of hot water, chiseling, chiseling plus cooling, chemical scarification and control. In evaluating the effect of the treatments were determined the germination percentage, mean germination time, germination speed index and relative frequency of germination. Scarification with sulfuric acid increased the germination of I. indivisa and I. purpurea seeds and the germination speed index of I. purpurea seeds. The hot water treatment was more effective in promoting germination of I. grandifolia seeds, and reduce the average time of germination of I. grandifolia and I. purpurea seeds, so that in treatments for overcoming dormancy there are synchronization of the germination process.