Two field trials (Los Andes 1998-1999 and Santiago 2004-2005) were carried out to determine growth inhibition of yellow nutsedge (
Cyperus esculentus
L.) and bermudagrass (
Cynodon dactylon
(L.) Pers.), growing on the plantation row, by mulch derived from a rye (
Secale cereale
L.) cover crop established between grapevine (
Vitis vinifera
L.) rows on overhead (cv. Flame Seedless) and vertical (cv. Cabernet Sauvignon) training. Spring mowing of the rye sown in the fall allowed for developing a thick and long lasting mulch along the grape rows. Nutsedge and bermudagrass control was 81 and 82%, respectively, and was more effective than conventional chemical (in the row) + mechanical (between rows) control. Glyphosate at 2% for nutsedge and 1% for bermudagrass control, applied twice (October and December), was insufficient to control either perennial weed adequately. Total broadleaved and grass/sedge weed control was 67.3 and 43.0% more effective with the rye mulch than with conventional treatments at Los Andes and Santiago, respectively. Perennial weed control levels could be explained as the new foliage of yellow nutsedge and bermudagrass was particularly susceptible to the shading provided by the rye mulch assembled prior to mid spring shoot emergence, and this effect remained active up until the beginning of autumn. The subsequent rye foliage mowing at the vegetative stage fully expressed the allelopathic effect produced by this local rye cultivar. The use of rye cover crop management and mulch could be applied as an effective weed control technique in conventional, as well as organic deciduous tree orchards.
