Physiological quality of hybrid maize seeds during containerized-dry storage with silica gel

Abstract

Seed storage operations in the tropics would benefit from low input techniques that can maintain seed physiological quality for considerably long periods without investments in cooling. A study was conducted to evaluate seed vigour and estimate seed longevity in maize during dry storage with commercial desiccant (silica gel) at various levels of gel/seed ratios in air-tight containers under ambient tropical temperature. Seed moisture content (MC) was lowest indicating effective drying at 1:1 gel/seed (100 g of seed stored over 100 g of gel) and 1:2.5 gel/seed ratio (100 g of seed stored over 80 g of gel) during 2 trials set up in 2005 and 2006. After 4 months of storage, laboratory seed germination capacity and vigour variables were consistently higher (p<0.05) in seed lots stored at 1:1 and 1:2.5 gel/seed ratios than seed lots stored at 1:20, 1:10 and 0:1 gel/seed ratios in the 2 trials. Probit analysis of seed survival data from controlled deterioration (CD) tests showed that estimates of potential longevity were optimal at 1:2.5 gel/seed ratios in the two experiments. The results indicated the possibility of maintaining seed physiological quality in containerized-dry storage under ambient humid tropical storage conditions. Moreover, the storage system experimented in the study simulated a condition that eliminates labour involved in regenerating or drying silica gel, since silica gel was not changed throughout the storage period. Gel/seed ratios between 1:1 and 1:2.5 are recommended for direct application or in developing technology and equipment for containerized-dry seed storage in the humid tropics.