Performance of spring wheat under summer rainfall winter irrigated conditions in Zambia

Thumbnail Image
Tembo, Batiseba
Journal Title
Journal ISSN
Volume Title
A study was conducted at Zambia Agricultural Research Institute at Mt.Makulu in Chilanga, Lusaka province of Zambia to study the comparative performance of five spring wheat varieties (UNZAWV1, UNZAWV2, Coucal, Sahai and Loerrie II) in two growing environments (seasons), that is the rainy season under rainfed conditions and under irrigation in the cool dry winter season at different seed rates, i.e 60, 80, 100, 120 and 140 kg/ha. The treatments were replicated four times in a split plot of a randomized complete block design. The varieties were assigned to the main plots with seed rates as subplots. Grain yield, ear length, grains per ear, number of tillers per square meter, leaf area index, root biomass, peduncle length, plant height, days to heading and days to maturity were recorded for each plot. Intra season and a combined analysis for season 1 and season 2 was carried out. The varieties did not differ significantly in yield, biological yield, 1000- grain weight, ear length, number of tillers per meter square, leaf area index, grains per ear and days to maturity across seasons. Varieties differed significantly in plant height and peduncle length across seasons. Seasons significantly influenced grain yield and all the yield components, plant height, days to heading and days to maturity. The irrigated season had a greater yield compared to the rainy season. The results also indicated that seed rate significantly affected grain yield, biological yield and days to heading across seasons. However all the yield components including plant height were not affected significantly by seasons. Seed rate of 140 kg/ha gave the highest yield of 1392.30 kg/ha while 60 kg/ha gave the lowest yield of 1077.04 kg/ha across seasons. A simple correlation across seasons showed number of tillers per square meter, grains per ear and above ground biomass as being the most important traits explaining the variation in grain yield across seasons. Plant height, days to heading, ear length, 1000- grain weight, days to maturity showing a marginal effect. This study therefore indicates that targeting the characters that most affect grain yield such as number of fertile tillers per square meter, grains per ear and above ground biomass would lead to greater yield performance under both rain fed summer and irrigated cool dry conditions. This would even encourage wheat production in summer rainfall environment among both commercial and small scale farmers as the cost of production arising from irrigation would be cut down