ADIGUN J.A.
Abstract
Field trials were conducted to assess the critical period of weed interference in tomato on the farm of the Institute for Agricultural Research Samaru (11011 'N, 07° 38'E) in the Northern Guinea Savanna ecological zone of Nigeria in 1989 and 1990 wet seasons and at the Irrigation Research Station of the Institute for Agricultural Research, Kadawa (11039'N, 08° 02'E) in the Sudan Savanna ecological zone of Nigeria in 1987/88 and 1988/89 dry seasons. Each trial consisted of two sets of treatments. One set of treatments consisted of plots initially kept weed free for 3, 6, 9 and 12 weeks after transplanting by weeding with hand hoes and subsequently kept unweded until harvest. The other set of treatments consisted of plots initially kept weed-infested for 3,6,9 and 12 weeks after transplanting and subsequently kept weed-free until harvest. Two treatments of weed-infestation and weed- free throughout the crop growth were also included as checks. In all the trials, weed interference beyond 6 weeks after transplanting (WAT) significantly depressed various crop growth parameters and tomato fruit yield compared with the crop kept weed-free throughout its life cycle. The crop was most critically affected by weed interference between 3 and 6 WAT. In order to obtain tomato fruit yield comparable to that of weed free check, it was required to keep the crop. weed-free for 6 weeks after transplanting and beyond. Weed infestation throughout the crop life cycle resulted in about 40 to 60% reduction in potential tomato fruit yield compared with the maximum yield obtained in each trials.
Key words:
Weed interference, critical period, transplanted tomato.