Allelopathic effects of the weed, Polygonum orientale L. on jute

The allelopathic potential of Polygonum orientale L. was investigated under laboratory conditions and pot experiments in field conditions. Air-dried different parts (viz. leaf, stem, and root) and whole plant of the weed aqueous leachate at 2.5, 5, and 10% (w/v) concentrations were applied to determine their effect on jute (Corchorus olitorious L. cv. JRO 524) seed germination and seedling growth under laboratory conditions. Increasing concentrations of P. orientale whole weed plant leachates inhibited seed germination and seedling growth of jute than the individual leaf, stem, and root leachates of the weed. Increasing concentrations from whole weed plant followed by weed leaf, stem, and root of this weed significantly inhibited water uptake by jute seeds. The decrease in germination of jute seeds was also correlated with increased electrolyte leakage. Air-dried weed residues of whole weed plant (i.e. 2.5, 5, and 10g) incorporation in soil or application in soil surface also inhibited seed germination and seedling growth of jute seeds in pots at field conditions. The germination, root and shoot lengths inhibition were higher in soil surface placed dry weed residues than soil incorporated dry weed residues.