Allelopathic effect of sesame varieties on germination and seedling growth of cowpea and okra

A study was undertaken to examine the allelopathic effect of leachates prepared using different sesame varieties of India on germination and seedling growth of cowpea and okra seeds. The allelopathic potential of sesame varied with the varieties. The leachates of sesame varieties reduced the germination percentage of cowpea and okra by 5 to 62.5 % and 8.33 to 53.85 %, respectively, compared to control. Impairment of metabolic activities due to the application of leachates resulted in decreased root and shoot length of both the test crops. Compared to control, the leachates inhibited the seedling fresh weight by 23.02 to 55.77 % and 7.27 to 52.73 %, respectively in cowpea and okra. The sesame varieties, GT-10 and TMV-7 recorded the highest inhibitory effect on the germination parameters, seedling growth attributes, soluble protein content and ascorbic acid content of both the test crops. The presence of higher concentration of allelochemicals like phenolic acids, flavonoids, alkaloids etc. in the varieties might have attributed the inhibitory effect. Therefore, cowpea and okra might not be suitable for sequential cropping with sesame.