Estudo de diferentes técnicas de armazenagem para conservação de sementes nativas do semiárido paraibano.

Abstract

The socioeconomic problem of the Northeast region is complex, and there is no magic formula to save the Northeast. The semiarid is a very vast, populous and poor region. It includes an area which is bigger than the 32 countries area of the 33 countries that compound the Europe. More than 24 millions of brasilians live in this region. The man always has been together the technological advance and the self-destructing, since he lives an inevitable evolutionary process. The technology had maked the man cause the serious environmental impacts that culminated in the disappearance of several botanical species. In this context, it's necessary to preserve the species mainly the ones which can be extinct soon. Therefore this work has been the objective of evaluating the physiological quality (germination and vigor) of (Mulungu, Pauferro, Jatobá and Pereiro) botanical species seeds, which are native from the semiarid, when they are stored in glass fibre silos, in dry chamber (in paper sacks at 10°C and UR of 28 %) and in cryostorage at the temperature of 196°C during the periods of 105 days in environmental conditions of the municipality of Campina Grande. The labratories stages of this work have been realized in the cryogenics department of the Labortory of Storage and Processing of Agricultural Products of Agricultural Engineering Department of UFPB. The methodology had had two stages. The first one was the stage of the collection of seeds in the interior of the state of Paraíba, followed by the cleaning, purification and tests to observe the break of the dormant jatobá and mulungu seeds, which is physiological, by the treatments: preheating, soak, immersion in nitrogen and cut. In the second stage, the seeds were submitted to the storage technique, that was showed above, by a period of 105 days. It can be conclued by the obtained results that: a) The mechanical cut was the best technique to surpass the dormant jatobá seed, that is physiological, among the methods of the break of the dormant seed and the best methods for the mulungu seeds were the immersion in N2L and mechanical cut. b) The jatobá seed has its physiological quality (germination and vigor) preserved, during the 105 days, when they're stored in environmental conditions of the city of Campina Gande. When they are stored in dry chamber or under cryostored, their phisicological quality decreases. c) The physicological quality of the mulungu seed was best maintained when it was stored in dry chamber, followed by the storage in natural environment and cryostorage. The factors (physiological quality preservation - germination and vigor -, natural ambient, technique dry chamber and cryostorage were analyzed in a period of 105 days. d) The pau-ferro seed demonstrated that it preserves its physiological quality during ali the stored period in ali the tested techniques (natural ambient, dry chamber and cryostorage. The cryostorage indicated the biggest averages among the tested techniques. e) The storage technique in environmental conditions of the city of Campina Grande was the one which best preserved the physiological quality of the pereiro seed, during the 105 days of storage. f) The jatobá, mulungu and pereiro seeds presented fissures of embryonic leaves, which can explain the decrease in the physiological quality of these seeds, when there are submitted to cryostorage, and the pau-ferro gather adequate conditions to be stored with immersion in liquid nitrogen.