Produção e armazenamento de sementes de Crotalaria ochroleuca e Crotalaria spectabilis

Abstract

Crotalaria is one of the main crops used for green manuring, but one of the great challenges of cultivation refers to the low availability of seeds with satisfactory quality in the market. Knowledge about the quality of seeds is a relevant factor for establishing an adequate stand. In seed production, knowledge of sowing spacing and factors that may interfere during storage contribute to obtaining seeds with high physiological quality. The objective of this work was to evaluate the production and storage of seeds of Crotalaria ochroleuca and Crotalaria spectabilis. In the first chapter, the objective was to evaluate the physiological potential of the seeds of the two species, produced in two spacing between rows (20 and 40 cm) in a randomized block design during two agricultural years (2018 and 2019), in Dourados-MS. The evaluations carried out were: germination, accelerated aging, field emergence, length of the aerial part and of the seedling root, dry mass of the aerial part and of the seedling root, electrical conductivity and cold test. In the second chapter, the objective was to evaluate the physiological potential of Crotalaria ochroleuca and Crotalaria spectabilis seeds stored in a kraft paper bag during storage in an air-conditioned chamber (15°C, 45% RH) at the Seed Technology Laboratory of the Federal University from Grande Dourados and uncontrolled environment for 0, 90, 180 and 270 days. The design used was completely randomized, in subplots divided over the storage periods with four replications, and in each period the water content, first count, germination, germination speed index, accelerated aging, field emergence were evaluated. , length of aerial part and seedling root, dry mass of aerial part and of seedling root and cold test. The 20 cm spacing was more efficient to produce C. ochroleuca seeds with greater physiological performance, but C. spectabilis seeds produced under 40 cm spacing showed higher germination and vigor than in the smaller spacing. Storage of C. ochroleuca and C. spectabilis seeds for up to 180 days provided higher germination and vigor results compared to newly harvested seeds. The two storage environments were efficient to preserve the physiological quality of the seeds.