Abstract
Two weed control experiments with sweet cherry peppers were conducted on a drip-irrigated Fraternidad clay at the Lajas substation in 1991 and 1992. In the first experiment, plastic mulch on the row plus paraquat at 0.56 kg ai/ha, directed postemergence between the rows, controlled practically all the weeds. Napropamide at 2.28 kg ai/ha and clomazone at 1.12 kg ai/ha as a pre-plant application, followed by paraquat at 0.56 kg ai/ha, were less efficient in controlling weeds than plastic mulch plus paraquat. In the second experiment, plastic mulch plus paraquat showed excellent weed control all season long. The pre-plant and postemergence applications of either glyphosate or paraquat also provided good weed control. The use of plastic mulch plus paraquat significantly outyielded all other treatments in both experiments.