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 mainly due to germination. Trials on the effectiveness of gibberellic acid (GA₃) for controlling storage losses were carried out on the two main species of yam (D cayenensis rotundata and D alata) grown in the Ivory Coast. Methods of application at the apex adapted to the rural environment were tested. Treatment with GA₃ prolonged the dormancy period and thus reduced losses. This substance was effective at low concentration with a long soaking duration (75 mg litre⁻¹ for 2 h) and during a soaking of short duration with a higher concentration (0·5 h at 150 mg litre⁻¹). Because of its stability at ambient temperature, the solution was still active 3 days after being prepared and after reuse of the same dip six times. © 1998 SCI.