Investigating the effects of low input drying procedures on maize (Zea mays L.), cowpea (Vigna unguiculata L.) and bambara groundnut (Vigna subterranea (L.) Verdc.) seed quality in Benin

Abstract

Four drying regimes (sun, shade, silica gel and conventional drying room) were compared using seeds of Zea mays L. (cv. DMR-ESR-W), Vigna unguiculata (L.) Walp. (cv. NI 86-650-3) and Vigna subterranea (L.) Verde. {local white va­riety). The seeds were harvested before mass maturity, at mass maturity and after mass maturity. Moisture contents of seeds were measured on wet basis ac­cording to ISTA rules and seed viability was determined through germination tests before and after drying. Silica gel al­lowed the lowest moisture content to be attained in all three species when seeds were harvested at mass maturity: Zea mays (7-5%), Vigna unguiculata (3-2%) and Vigna subterranea {8%). Sun drying as a low-cost alternative also allowed low moisture contents to be reached: 3.9-7.8% for maize, 3.2-5.1 % for cowpea and 8.4-9.6% for bambara groundnut. For all drying regimes, most of the seed samples germinated well, with a mean time to germination between 3 and 5 days for all the crops studied