DESICCATION TOLERANCE AND PHYSIOLOGICAL DETERIORATION IN SQUASH SEEDS (Cucurbita moschata Duchesne ex Lam.)

Abstract

Desiccation tolerance, physiological quality and harvest time were evaluated in squash (Cucurbita moschata) seeds. A seed production plot was established at the Experimental Research Station of the Universidad Autónoma Chapingo, State of México, in the SpringSummer season of 1999. Fruits were harvested at 40, 70 and 100 days after anthesis (daa). Then seeds were extrated at 0 or after 60 days under storage conditions. Seeds were dried at environmental temperature or by hot air, and then stored for 0 or 60 days. Seed test were standard germination and germination rate, with treatments distributed in a complete randomized factorial experimental design with four replicates of 25 seeds, in each test. Fruits harvested 40 daa showed the least germination and germination rates which were 38.8 and 71.2 % lesser than that of seeds from fruits harvested 100 daa. Fruit post-maturation storage largely improved the physiological quality of young seeds, since seeds of fruits harvested 40 daa showed increases of 51 and 61 % in seedling emergency and germination rate, respectively. Even seeds of fruits harvested 70 daa increased those rates by about 69 and 83 %.