Allelopathic Efficacy Of Two Crop Field Weeds On Growth Attributes Of Some Selected Rice Cultivars

Abstract

Weeds are causing huge loss on the crop yield by exhibiting the harmful effects on the from seed germination up to the yield of the crops due to several factors such as competition for space, light and nutrients and allelopathy. In the present study  an attempt has been made to evaluate the various concentrations (0,5,10,15,20 and 25%) of whole plant aqueous extracts of weeds, Cyperus rotundusL.( Purple nut sedge) and Cynodan dactylon(L.) Pers. (Bermuda grass) were tested for assessing their allelopathic efficacy on growth attributes of some rice (Oryza sativa L.) cultivars i.e.ADT-36,BPT-5204 and IR-20 using pot culture experiments. The experimental results revealed that all the concentrations of both the weed extracts had inhibition on germination percentage, seedling length, number of,dry weight and chlorophyll contents of 15 day old seedlings of all the three rice cultivars and the inhibitory effect of the extracts was concentration dependent. However, at 5% of C. rotundus and10% of C. dactylon extracts did not affect seed germination of IR-20 . Among the rice cultivars, the higher degree of growth inhibition was observed in ADT-36followed by BPT-5204 and IR-20 . The weed C.rotundusexhibited more intense on growth suppression of rice cultivars thanC.dactylon.