Madurez fisiológica, germinación y conservación de semillas de guayabito (Psidium cuneatum Camb.-Myrtaceae)

Abstract

Psidium cuneatum Camb., "guayabito or arasá blanco" is a species native to the Misiones province and the north of Corrientes, where it is of ecological importance and a potential commercial interest. This species is currently affected by the advance of commercial forestations. The aim of this study was to analyze the germinative behaviour of seeds of this species according to the maturity of the fruits, the germinative conditions and storage under different environments. A few trees were labelled and submitted to weekly observations for two years. It was established that fructification takes place from December to July and the fruits remain on the trees during a long period before they fall off. The germination of seeds from fruits of different sizes, which was assessed by means of the velocity index and germinative percentage, showed that the seeds of fruits with diameter larger than 1.5 cm performed better, so that the fruit size is an appropriate indicator of maturity in this species. On the other hand it was confirmed that 27 °C is the best temperature for germination percentage and velocity. To establish the best conditions for conserving the seeds, they were stored during 30, 90, 180, and 270 days combining different packaging and temperatures. The results indicated that hermetic packaging was more effective for the conservation of the germinative index when combined with low temperatures even though, after 180 days, a significant reduction in the germinative index (32%) was verified.