Abscission responses of petiolar explants of Capsicum varieties to treatments with growth substances and their combinations

Abstract

The abscission responses of petiolar explants of NP 46-A and Pusa jwala cultivars of chilli (Capsicum annuum L) to proximal and distal applications of growth substances were investigated. Ethephon, abscisic acid and ascorbic acid proved to be accelerants of abscission irrespective of age of explants and site of application. The synthetic auxin (naphthalene acetic acid) retarded abscission in younger explants regardless of the site of application but in the older explants proximal application of the auxin promoted abscission while distal application retarded the process. Gibberellic acid showed effects opposite to those caused by the auxin. The proximal application of gibberellic acid retarded abscission irrespective of age of explants while distal application effectively accelerated abscission. The cytokinin (benzyl adenine) and morphactin delayed abscission of petiolar explants on distal as well as proximal applications. The abscission responses to combinations of growth substances were highly variable depending on the age of explants, site of applications and varietal source of experimental material. The morphactin and benzyl adenine exhibited additive interaction in retarding the abscission up to such extent that ethephon and abscisic acid could only partially counteract their effects in combination of two growth substances. The auxin and gibberellin showed irregular and mixed interactions with other bioregulants studied.