Seeds of four improved varieties of cowpea (Vigna unguiculata L. Walp), 'Modupe', 'Ife Brown', 'IT-69D-610' and 'TVX 3236', were adjusted to three moisture levels: 10%, 15% and 20% to determine the appropriate moisture level to maintain the viability and vigour of seeds and to investigate the extent to which duration of storage affects their viability and vigour. Response of cowpea seeds was assessed by standard germination test, accelerated ageing test, saturated salt accelerated ageing test and bulk conductivity test. The moisture contents of the seeds were determined gravimetrically, before being conditioned to 10%, 15% and 20% moisture levels. Cowpea seeds maintained at 10% had the highest viability and vigour irrespective of the duration of storage. Irrespective of genotype, there was a progressive significant decline in the germination potential during the storage period. While viability loss was negligible when seeds were stored at 10 and 15% moisture contents, germination of seeds stored at 20% decreased by 35.59% in the second month and by another 30.28% in the third month. Thus, there was an inverse relationship between moisture contents of cowpea seeds and the viability and vigour of the seeds in storage.

seed deterioration, germination, vigour, accelerated ageing, longevity

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia