SOME STUDIES ON ALLELOPHA TIC POTENTIAL OF CYPERUS ROTUNDUS L.

Abstract

Cyperus rotundus (sedge weed) that exhibit allelophatic behaviour represent potential options for sustainable weed management. Previous study has shown that application of mulch from the weed suppressed broadleaved weed. Hence, in this study we carried out a series of experiments to elaborate whether the weed has an allelophatic potential for broadleaved weed control. Consistent with the previous study, the result of a field experiment in this study show that biomass aplication of C. rotundus as mulch, compost and soil ameliorant suppressed broad leved weed in soybean cultivation. However, a green house experiment show that biomass aplication had no negative effect on the growth and biomass production of 3 common broadleaved weeds, Asystasia ganggetica, Mimosa pigra and Borreria alata, and soybean. Study on the effect of the concentration of water extract of C. rotundus (0.5 - 4.5 kg/L) show that up to 1.0 kg/1 concentration significantly decreased (more than 60%) seed germination of the three common broadleaf weeds in upland; but had no effect on seed germination of soybean. Analysis of allelochemical componds indicated that phenolic compounds from C. rotundus, cyperene and culmorin were specific compounds that only found in fresh C. rotundus with aquadest sovent The study indicates that C. rotundus may be used as an option for seed germination control ofbroad leaf weeds.