Rice seed quality as influenced by storage duration and package type in Cameroon

Abstract

The study aimed at evaluating the changes in rice seed quality as a function of storage duration and package type through characterization of seed quality determinants. Two rice varieties NERICA8 and NERICAL56) were measured into four package types (nylon bag, polyethylene bag, jute bag, and paper bag) and stored in a storage room of average relative humidity and temperature of 80% and 26 °C respectively. Standard methods of evaluating seed quality applicable to paddy were used. The quality parameters showed variability across the package types and storage duration. Remarkable changes were observed in the germination rate and insect damaged grains with slight changes in the number of colored grains, moisture content, and grain weight during the sampling intervals. The quantity of insect damage grains increased while germination rate decreased continuously during the entire experimental period. At three months of storage, the quantity of insect damage grains increased in all the bags for NERICA8 (0.1 g - 3.73 g) and was so for NERICAL56 only in the jute (0.15 g - 3.43 g) and paper (0.1 g - 3.13 g) bags at p<0.05 level of significance. Germination rate had reduced in all the bags below the minimum seed certification standard (MSCS) of 85%, reaching values of 53% and 51% for NERICA8 and NERICAL56 respectively in the polyethylene bag. Insect damage was least in the polyethylene bag (1.73 g) and highest in the jute (3.73 g) and paper (3.43 g) bags. NERICA8 was more pruned to insect damage as high values were observed at one month of storage but observed for NERICAL56 only at two months of storage. In addition, the number of colored grains was higher in the polyethylene and nylon bags compared to the jute and paper bags. From these results, a huge decrease in the quality of rice seeds occurred in the nylon and polyethylene bags. The observed high germination rate associated with insect infestation in the jute and paper bags suggest that if seeds in these bags are treated with insecticides, germination rate could improve to values around the MSCS even after three months of storage.

Keywords: Seed quality, NERICA, germination, insect damage.