Comparison of osmopriming and seed coating with calcium salts for green bean performance under field conditions. II. Stand establishment, chlorophyll fluorescence and yield

Abstract

Seed coating is commonly used to supply fungicides and micronutrients to enhance seed quality. The primary reason for using mineral elements in seed priming is to regulate water absorption. Osmopriming and seed coating were compared for their effect on crop stand establishment, seedling chlorophyll fluorescence and seed yield in six green bean (Phaseolus'vulgaris L.) cultivars (‘Imbali’, ‘Sodwana’, ‘Elangeni’, ‘Tongati’, ‘Tokai’ and Outeniqua'). Three calcium salts (CaSO4, CaCI2 and Ca(NO3)2) at five molarities (1,10, 50,100 and 1000 mM) were also compared as constituents of the priming solutions and seed coatings. Control seeds were not primed or coated. Osmopriming and seed coating improved crop stand establishment, reduced seedling stress as determined by chlorophyll fluorescence, and resulted in increased seed yield. However, seed coating was a better seed enhancement technique than osmopriming, regardless of calcium salt used. Both stand establishment and reduction of seedling stress were better with CaSO4 compared to CaCI2 and Ca(NO3)2 seed coating, which did not significantly differ. Crop yield, however, showed an equal response to CaSO4 and Ca(NO3)2), which was better than the response to CaCI2. Significant differences between cultivars were observed. However, no clear evidence was found to suggest that cultivar differences were not merely genotype related. It is suggested that the molarity of calcium salts in osmopriming and seed coating should not exceed 50 mM.