INFLUENCE OF SEED PRIMING ON GROWTH AND SEED YIELD OF OKRA UNDER WATER STRESS

Abstract

Seed priming is a technique that improves seed performance in the field and hence ameliorates subsequent germination, growth and seed yield. Moreover, seed priming is often implicated in improving the stress-tolerance of germinating seeds. This study was initiated to determine the seed yield and quality of a local genotype okra var. Sabahia in relation to seed priming and water stress. Two field experiments were conducted during the summer seasons 2012 and 2013 at Kaha (Kalyiobia Governorate), Horticulture Research Station, Egypt. The experimental design used is split plot with four replications. The main plots represented two irrigation regimes either normal or stress 20 days or 30 days intervals respectively, whereas the priming treatments represented the subplots. For priming treatments, seeds were soaked for 24 hours either in water (hydropriming) or in a 3% solution of Na2HPO4, MgSO4, or KCl (osmopriming), whereas dry seeds represented the control. Results indicated that all plant traits determined were reduced under water stress while this reduction was improved in the primed seeds. Using Na2HPO4 or MgSO4 seed priming treatments under both water regimes applied gave the highest and best results regarding plant growth, seed yield and quality. Obtained results also showed that seed priming with KCl gave lower positive effects in this concern and such results seemed to be higher than those obtained by hydropriming treatments. In addition, results clearly showed that okra plants could resist the applied water stresses treatments as a result of seed priming processes used which were found to cause accumulation of some osmolytes as proline. Data of the present work showed proline accumulation in response to water stress, which might assume that this osmolyte could be enhanced by seed priming. Generally, it could be concluded that seed priming results in improving growth and seed criteria of okra especially under water stress conditions.