Controlled Deterioration and Predicting Viability of Okra Seed in Storage.

Conservation of okra [Abelmoschus esculentus(L.)Moench] germplasm is mainly by seed storage in gene banks. Efficient management of seed collections, especially under tropical conditions, requires the ability to quantify and predict seed viability during storage. To quantify longevity of okra seed for purposes of viability prediction, two controlled deterioration (CD) experiments were conducted. In the first experiment, seed of six accessions of okra were stored at 45°C and 60% relative humidity (RH), and germination determined at 0, 3, 5, 10, 20 35, 50, 70, and 100 days to estimate probit seed longevity parameters. Mean probit seed longevity (P50) was 102.59 ± 38.21 days, indicating that okra seed are long-lived compared to a longevity marker species,Brassica napus(L.). In the second experiment, constants of a model for predicting viability were determined for okra seed stored for 300 days at 45°C and 2.19 to 12.9% seed moisture content (MC). The fit of log σ and log MC wasR2= 0.90 when log σ data for okra seed dried below 4.09% MC were not included in the fit. Estimates of derived viability constants wereKE= 6.659 andCW= 2.448. Estimated viability constants should be used for viability predictions under typical tropical ambient storage and practical gene bank storage conditions. [ABSTRACT FROM AUTHOR]