Abstract

Cleome gynandra is an edible African indigenous leafy (AIL) vegetable highly consumed by local communities in most provinces of South Africa (SA). However, C. gynandra is not formally cultivated in SA, but rather found commonly growing naturally under disturbed soils, especially in small holders backyard. Seeds of C. gynandra comprise physiological dormancy, which prevent germination after pod harvest. The objective of this study, therefore, was to investigate the effect of seed storage followed by pre-chilling (PC) treatment on emergence percentage (EP) of C. gynandra seeds. Eight months stored seeds of C. gynandra were pre-chilled for 0, 6, 12, 18, 24 and 30 h at 4°C. The non-chilled (0 h), but stored seeds represented the control. After PC treatment, all seeds were germinated in seedling trays filled with Hygromix growing media in vivo. Treatments were arranged in a randomized complete block design, with 10 replicates. The total number of emerged seedlings was recorded daily until no further emergence was observed (30 days). The collected data were calculated and expressed as EP and mean emergence time (MET) prior to analysis through SAS software. Both the stored, non-chilled seeds at the control and the stored-PC seeds emerged. Pre-chilling treatment had significant (P.0.05) effect in EP, contributing 17% of total treatment variation in C. gynandra stored seeds. No significant effects were observed in MET of C. gynandra stored seeds. Relative to the non-chilled seeds at the control, at 6 and 12 h, PC treatment increased EP of stored seeds by 3%. However, when PC duration was further increased, EP decreased by 22 to 51%. Optimum EP of 60% was achieved when stored seeds were PC for an optimum duration of 4 h. In conclusion, PC enhanced germination thereby increasing EP of C. gynandra stored seeds.