Allelopathic Effect of Fresh and Dry Cleome rutidosperma DC. Extracts on Seed Germination and Growth of Echinochloa crus-galli Beauv. and Amaranthusspinosus L.

Abstract

Allelopathic effects of fresh and dry Cleome rutidosperma DC. extracted by water
on germination and seedling growth of Echinochloa crus-galli Beauv. and Amaranthus
spinosus L. were tested at concentrations of 1, 5, 10 and 15 mg/ml The results indicated
that the concentrations of extract from fresh Cleome rutidosperma DC. at 5, 10 and 15
mg/ml could completely inhibit 100 of percent seed germination, root length, shoot length,
and dry weight of Echinochloa crus-galli Beauv. and Amaranthus spinosus L. While, at the
concentration of 1mg/ml could stimulate seed germination and growth. The concentrations
of extract from dry Cleome rutidosperma DC. at 15 mg/ml, showed the best result in
inhibiting seed germination and growth. This indicated that allelopathic from fresh Cleome
rutidosperma DC. had more efficiency in inhibit the seed germination and growth than dry
metter. The low concentration of fresh Cleome rutidosperma DC. could stimulate and
promote the seed germination and growth of Echinochloa crus-galli Beauv. and
Amaranthus spinosus L., where as the high concentration could inhibit the seed
germination and growth. A broad leaf weed Amaranthus spinosus L. would be more
affected than a narrow leaf weed Echinochloa crus-galli Beauv.