INFLUENCE OF SEED TREATMENT ON THE ENHANCEMENT OF GERMINATION AND SEEDLING VIGOUR OF PAPAYA

Abstract

Papaya is mainly propagated through seeds. The seeds are covered with sarcotesta, a whitish succulent and translucent material which has been reported to delay germination. The freshly extracted seeds exhibit dormancy when sown immediately and the dormancy can be broken by after-ripening by storage for a short period, but prolonged storage also results in poor germinability. Treatment of seeds with growth regulators and certain chemicals has been found to break dormancy and improve the germination. Hence an experiment was conducted in order to study the effect of various chemicals on seed germination and seedling growth of papaya. The experiment was carried out in completely randomized design with fifteen treatments in three replications. The treatments included soaking the seeds in GA 3 (50, 100 and 200 ppm), NAA (100 and 200 ppm) and thiourea (1000, 2000 ppm) for 6 and 12 h duration along with a control. The results revealed that seeds soaked in GA 3 200 ppm for 12 h reduced the time taken for 50% germination, increased root and shoot length and vigour index followed by seed treatment with thiourea 2000 ppm for 12 h. The least values were recorded in the control.