Herbicidal activity of n-hexane, ethyl acetate and methanol purple nutsedge (Cyperus rotundus L.) extracts on Amaranthus spinosus L.

Abstract

Environmentally friendly weed control is highly recommended to be implemented in agriculture. The objective of this research was to assess the herbicidal efficacy of n-hexane, ethyl acetate, and methanol extracts derived from the tuber of Cyperus rotundus L. on Amaranthus spinosus L. The tuber was consecutively extricated with n-hexane, ethyl acetate, and methanol. These extracts were given to A. spinosus in pot culture at concentrations of 5%, 10%, 15%, and 20%.The herbicide (2,4-D at 0.686 kg a.i. ha−1) and distilled water were acted as positive and negative controls. The extract had variable effects on weed control percentage, leaf area, root length, shoot and root dry weight of A. spinosus. Major compounds in GC-MS in n-hexane of C. rotundus extract were: 7-Isopropenyl-1, 4a- dimethy l-4,4a,5,6,7,8-hexahydro-3H-naphthalen-2-one (19.60%), phthalic acid (7%), dibutyl phthalate (3.97%); in ethyl acetat extract were propanetriol, 1-acetate (37,40%) and 7 Isopropenyl-1,4a-dimethyl-4,4a,5,6,7,8-hexahyro-3H-naphthalen-2-one (6.42%); in methanol extract were d-glycero-d-ido-heptose (21.31%) and octaethylene glycol monododecyl ether (39.15%). The 20% of those extracts causing 53.33%, 64.33% and 55.33 destruction of A. spinosus respectively at 14 Days After Aplication. Thus, ethyl acetate is the most potent herbicide extract to be developed as an agent against A. spinosus.