SOIL PHENOLICS AND THEIR EFFECT ON PLANT GROWTH

摘要

Phenolic compounds present in black cotton soil, red loamy soil and alluvial soil were quantified. The effect of phenolic compounds on germination of mustard (Brassica juncea) and greengram (Vigna radiata) was studied by using catechol as a test phenol. The results showed that red loamy soil contained higher quantity of total phenols (1.05 mg/kg) and ortho- dihydroxy phenols (0.849 mg/kg) than the other samples (black soil contained 0.724 mg/kg total phenol and 0.934 mg/kg ortho dihydroxy phenol, alluvial soil 0.649 mg/kg total phenol and 0.66 mg/kg ortho dihydroxy phenol). The qualitative analysis showed that only two phenolic compounds were present in the alluvial soil, three in black cotton soil and red loamy soil contained four compounds. Catechol, the test phenol reduced the per cent of germination of B. juncea by 5 per cent and shoot and root length by 13 and 22.8 per cent, respectively. Dry weight of the seedlings was reduced by 5.6 per cent germination of V. radiata was reduced by 35 per cent and shoot and root length by 60.9 and 27.9 per cent, respectively. Dry weight of the seedlings was reduced by 61.2 percent. V. radiata was more sensitive than B. juncea towards soil phenols.