USE OF GIBBERELLIC-ACID TO PROLONG DORMANCY AND REDUCE LOSSES DURING TRADITIONAL STORAGE OF YAMS

The annual vegetative cycle of the yam (Dioscorea spp) necessitates a long period of storage. Losses during this period are high and are mai nly due to germination. Trials on the effectiveness of gibberellic aci d (GA(3)) for controlling storage losses were carried out on the two m ain species of yam (D cayenensis rotundata and D alata) grown in the I vory Coast. Methods of application at the apex adapted to the rural en vironment were tested. Treatment with GA(3) prolonged the dormancy per iod and thus reduced losses. This substance was effective at low conce ntration with a long soaking duration (75 mg litre(-1) for 2 h) and du ring a soaking of short duration with a higher concentration (0.5 h at 150 mg litre(-1)). Because of its stability at ambient temperature, t he solution was still active 3 days after being prepared and after reu se of the same dip six times. (C) 1998 SCI.