Características morfo-agronômicas e deterioração controlada em sementes de Tagetes

Abstract

The species of the genus Tagetes, commonly known by Marigold, present easy cultivation, are quite ornamental and show a relatively long flowering cycle. T. patula L. cultivars present a full blooming during the summer and can be traded either as cut flowers or as potted plants. On despite of its economic importance, little is known about their morpho-agronomic characters as well as their seed viability. This research has been performed at Post-Harvest Technology Laboratory, Faculty of Agricultural Engineering, Campinas State University, UNICAMP and at Genetic Department, Campinas Agronomic Institute, IAC, aiming at verifying morpho-agronomic differences among cultivars as well as determining seed viability constants for the species. The cultivars tested were Spry, Orange, Flame and Yellow, from Tagetes patula cv. French Marigold Bounty series. The evaluation of seed physiological quality and the determination of the viability constants were carried out under controlled deterioration conditions (constant storage temperatures and moisture contents). Late flowering cultivars revealed higher plants and thicker stems, larger inflorescence leaves, higher dry matter contents in leaves and roots and shorter flowering periods. Otherwise, early cultivars presented higher number of inflorescences / plant and stem and longer flowering period. Cultivar Flame seeds revealed lower storability among the others cultivars. An inverse relationship was observed between moisture content and seed longevity. Different viability constant sets were estimated for the cultivars Spry, Orange, Flame and Yellows, as follows: KE = 13.82, 12.02, 12.70, 13.93; CW = 3.487, 2.147, 3.465, 3.544; CH = 0.3221, 0.3062, 0.2758, 0.3244; CQ = 0.002626, 0.002557, 0.002084, 0.002649, respectively. Viability equation constants for the species Tagetes patula were: KE =14.83; CW = 3.362; CH = 0.3691, CQ = 0.003076.