Abstract

Vigna radiata is one of the agriculture crops where yield is adversely affected by a physiological phenomenon, the abscission of young flower buds. The abscission zone at the peduncle base is characterized by the presence of small cells showing evidence of previous divisions. The micrographic evidence showed that the separation of the abscission zone cells was caused by rapid enzymatic degradation of the cell walls. Bio-assays with the explants containing young ( 6 day-old) flower bud were carried out under determined conditions. Effects of plant growth regulators IAA (2mg/l), BA (10mg/l) and GA3 (20mg/l) were investigated. The abscission was significantly reduced using 2mg/l IAA, indicating that endogenous auxins were required for normal growth of flowers. The effect of IAA is consistent with the "two-phase" theory of auxin on abscission.