GROWTH AND YIELD OF IRRIGATED TOMATO (LYCOPERSICON-ESCULENTUM-MILL) AS AFFECTED BY WEED ASSOCIATION

Field trials were carried out in 1987 and 1988 to determine the effects of weed association with irrigated tomato (cv. Ronita VFN) during the cool dry season at Maiduguri in the semi-arid zone of Nigeria. In these trials, weed infestation for 6 weeks after transplanting and later significantly depressed crop vigour in 1987 as compared with the crop kept weed free throughout its growth. Weed association after 3 weeks after transplanting till harvest reduced tomato fruit yield compared with the crop kept weed free for the corresponding periods. The critical period of weed competition was observed to be at 6 weeks after transplanting. Uncontrolled weed association till harvest resulted in 51.7% and 63% losses in 1987 and 1988, respectively, in potential tomato fruit yield compared with weed free period till harvest.