COMPARATIVE ALLELOPATHIC POTENTIAL OF TWO AIZOACEAE WEEDS AGAINST GERMINATION OF DIFFERENT CROPS.

Comparative allelopathic potential of two Aizoaceae weeds namely Trianthema portulacastrum L. and Sesuvium portulacastrum L. was studied against the germination and seedling growth of Pennisetum glaucum L. (millet), Sorghum bicolor L. (sorghum), Zea mays L. (maize), Triticum aestivum L. (wheat), Vigna mungo L. (mash), Vigna radiata L. (mungbean), Cyamopsis tetragonoloba L. (guar) and Helianthus annuus L. (sunflower) under controlled conditions. Five percent aqueous extracts of different plant parts of both weed species were prepared by soaking dried plant parts in distilled water in the ratio of 1:20 (w/v). The aqueous extracts of different plant parts (stem, leaf, root, seed and whole plant) of Trianthema portulacastrum and S. portulacastrum produced a significant effect on germination percentage, mean germination time, root/shoot lengths and seedling vigor index of all tested crops as compared to control. Further, the delay in germination and reduction in germination percentage of all test crops was more pronounced with T. portulacastrum than S. portulacastrum. The whole plant extract of T. portulacastrum proved most harmful to germination and seedlings growth of all tested crops than S. portulacastrum. Total water soluble phenolic acids analysis revealed that T. portulacastrum and S. portulacastrum contain compounds (caffeic acid, ferulic acid, Mcoumeric acid, P- coumeric acid, syringic acid, venillic acid; and caffeic acid, gallic acid, 4-Hydroxy-3- Methoxybenzoic acid, P-coumeric acid, syringic acid, respectively) in their tissues which may cause allelopathic effects under field conditions. [ABSTRACT FROM AUTHOR]