Maturação, repouso pós-colheita e armazenamento de sementes de Diospyros inconstans Jacq.

Abstract

The study aimed to analyze the behavior of seeds obtained from fruits of Diospyros inconstans Jacq. at different stages of maturation to subsidize the development of technologies for their conservation and management. Thus, the work is divided into three chapters: in the first, a bibliographic review on D. inconstans was carried out, aiming at compiling works and disseminating knowledge about the species. In the second, the biometry of fruits and seeds was evaluated, and the germination behavior of seeds obtained from freshly harvested fruits at three maturation stages (green, intermediate and reddish) subjected to constant temperatures of 20, 25, 30 and 35 ± 0.5°C; and for seeds of reddish fruits, tolerance to desiccation, slow rewetting and storage in vermiculite for 19 days were evaluated. In the third chapter, the experiments were carried out in three parts. In experiment 1, seeds obtained from fruits that had rested for seven days and separated into three color stages (COR1/7, COR2/7 and COR3/7) were used, dried at 36, 15 and 11% of water content and stored in a plastic bag in a refrigerator for a period of 90 days. In experiment 2, COR3/7 seeds with 11% moisture were used, stored in plastic bags in a refrigerator, for 90, 210, 270 and 360 days. For experiment 3, seeds obtained from fruits with a rest period of twenty days and separated into three color stages (COR1/20, COR2/20 and COR3/20) were used; subsequently, slow rewetting and storage for up to 270 days of fruit seeds classified as COR3/20 and dried at 15% were carried out. Seeds were evaluated for water content, germination/emergence percentage, germination speed index, mean germination time, seedling formation, length, collar diameter and dry mass of seedlings. The fruits are medium in size and have small seeds. The germination speed index was higher in seeds from reddish fruits, and seeds from green fruits originated betterdeveloped seedlings. Temperatures of 25 and 30 °C are recommended for conducting the seed germination test at the three maturity stages. Reddish fruit seeds are tolerant to desiccation at 10% water content, and slow rewetting and storage in vermiculite promotes faster and more uniform germination. The degree of maturation is an essential condition for the seedling production capacity, which is acquired towards the end of the maturation process. The speed and intensity of seedling growth are components affected when the seeds are obtained from fruits collected in advance, even remaining in post-harvest rest, but the speed and intensity of growth are increased when the water content of the seeds is reduced and slow rewetting (seven days) or seed storage was performed. The storage capacity of seeds from fruits with COR3/7 and COR3/20 colors was not harvested when the fruit is harvested in advance and associated with post-harvest rest, but requires drying of the seeds at levels close to 11%.