EFFECT OF PRE-HARVEST AND POST-HARVEST APPLICATION OF MORPHACTIN ON THE POST-HARVEST BEHAVIOUR OF OKRA

Weight loss, moisture percentage, chlorophyll contents, soluble sugars, starch, acidity and amino acids were determined for each concentration on the initial and final day. Anatomical changes in the fruits of the treated plants were also noted.

The results obtained clearly showed that:

1. the concentration of 2.5 ppm morphactin appeared to be the most effective, before or after harvest, with or without waxing, to control weight loss and to maintain the levels of all soluble compounds close to their initial values. Amina acids were found to be decreased with post-harvest application and increased with preharvest application. Post-harvest treatment with higher concentrations resulted in an increased physiological weight loss and concentrations higher than 10 ppm caused a marked degree of blackening on the very first day rendering the pods unmarketable.
2. the effectiveness of the concentration of 2.5 ppm morphactin, when applied before harvest, seemed to be corroborated by the induced anatomical changes-lower stomatal index and more numerous and longer trichomes, all of which could contribute to help water conservation by the pods.

Morphactin application could therefore be used as a new method to improve the post-harvest shelf life of okra pods and possibly other green vegetables. Their use is further advisable in view of the fact that morphactins are degraded shortly after treatment leaving no toxic residues.

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