CONTROL OF LEAF ABSCISSION IN NODAL CULTURES OF ANNONA-SQUAMOSA L

Attempts to micropropagate Annona squamosa L. (sugar apple) from nodal explants have been hindered by complete leaf abscission during establ ishment in culture. Absorbents and inhibitors of ethylene biosynthesis and action were tested in order to control leaf drop. The inhibitors of ethylene action, silver thiosulphate and 2,5-norbornadiene, were mo re effective in avoiding leaf abscission than absorbents of ethylene, activated charcoal, mercuric perchlorate and potassium permanganate, o r inhibitors of ethylene biosynthesis, aminoethoxyvinylglycine, aminoo xyacetic acid and cobalt chloride. The results suggest that silver com pounds can be used as effective inhibitors of leaf abscission in the e stablishment of Annona squamosa in culture.