1Departmenr of Plant Physiology, Sukhadia University, Agricultural Research Station, Sri Ganganagar-335001 (Raj.).
Department of Botany, Meerut University, Meerut (U.P.), India.
Experiments on NP 46-A and Pusa jwala varieties of Chilli (Capsicum annum L.) were conducted to study the action and ‘interactions’ of certain growth substances in leaf abscission. Auxin, cytokinin and morphactin have shown additive ‘interactions’ in retarding abscission when tested in combinations of two. Combinations where auxin was tested with abscission accelerants like gibberellin, ethylene and abscisic acid, later growth substances dominated in action resulting in abscission acceleration. The abscission accelerating action of ethylene and abscisic acid could only be partially counteracted by auxin and cytokinin. However, ascorbic acid failed to modify or reduce the action of auxin and benzyl adenine. Gibberellin has shown variety dependent variation in its effect when used in combination with cytokinin. Morphactin dominated in action in combinations with abscission accelerants. Mutual ‘interactions’ of any two abscission accelerants seemed to be non-additive in leaf abscission in general.
