Influence of Packaging Materials on Seed Germination of Cowpea Varieties during Short Term Storage

A storage experiment was conducted at the seed testing laboratory of the National Centre for Genetic Resources and Biotechnology (NACGRAB), Ibadan, Nigeria to examine the effect of packaging materials and storage periods on seed germination of cowpea. Seeds of two improved varieties of cowpea: Ife Brown and SAMPEA 12 were packed using three packaging materials viz. aluminium bags, plastic containers and envelopes. The seeds were dried to 12% moisture content with initial germination percentages of 90% and 88% respectively. The packaged seeds were stored under short-term storage conditions (temperature of 15.1 to 22.6°C and relative humidity of 26.9 to 50.7%) in Febrary 2015. The stored seed samples were drawn at three-month intervals starting from May 2015 to May 2016 which constituted five storage periods and evaluated for germination. The experiment was arranged in 2 x 3 x 5 factorial using completely randomised design (CRD) in three replications. The three factors were two varieties of cowpea, three packaging materials and five storage periods. The results of analysis of variance revealed that effect packaging materials were significant (P=.05) while an effect of storage period was highly significant (P<0.01) on seed germination of cowpea. The seeds packed in plastic containers recorded highest germination percentage of 75.9%. Germination values for seeds packed in envelopes (73.53%) and aluminium bags (70.20%) were not significantly different. Hence, plastic containers appeared to be the best for storage of cowpea seeds. Furthermore, increasing storage periods from 3, 6, 9 12 and 15 months resulted to declining in germination percentage with respective values of 91.4, 84.6, 74.4, 68.1 and 47.6%. Moreover, means for the interactive effect of variety by storage period revealed that cowpea varieties could retain viability values of 70% and above up to 12 months in storage at the present conditions used in the study.