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Title: Selection of bread wheat varieties for marginal areas of Kenya by simulating drought stresss
Authors: Kimurto, Paul Kiprotich
Keywords: Selection of bread wheat varieties for marginal areas of Kenya by simulating drought stresss
Issue Date: 2000
Publisher: Egerton University
Abstract: Kenya meets only 40% of its current national wheat demand of approximately 700.000 tonnes and it imports the balance of about 60%. Frequent droughts often causes crop failures especially in the marginal areas which consists of about 83% of the total land area. This makes it necessary to search for more drought resistant wheat varieties. Drought simulations using mobile rain shelters and drip irrigation would allow easy. cheaper and faster selection of drought resistant cultivars because it reduces cost of travelling and time consumed required from one location to another. Moisture regimes which simulated terminal. early, mid and late drought were created under a mobile rain shelter at Njoro in 1998 and 1999. to identify drought tolerant wheat cultivars and determine the most critical growth stage(s). 70. 82. 94 and 106 mm of moisture were applied up to seedling stage. tillering, anthesis and grain filling. respectively. then irrigation was tenninated to maturity. Control had 118 mm of moisture applied at all growth stages. Four wheat genotypes. R748. R830. R831 and R833 were tested with one check variety. Duma. Analysis of variance was carried out in each season and the two seasons combined. Correlation analysis was perfonned on five cultivars tested and yield stability test across watering regimes was also carried out. Terminal and early droughts caused significant reduction in yield and all yield components compared with control. had significant reduction in plant growth. tillers per plant. number of reproductive tillers and harvest index. Mid and late droughts (at reproductive stages) caused significant reduction in earlength, spikelets per head. reproductive tillers. harvest index. kernel weights and increase in number of sterile florets per head compared to control. The results showed that seedling and reproductive stages were the most sensitive to moisture stress. Genotype R748 performed quite well in all moisture regimes and it is recommended to be grown in marginal areas. like check variety Duma. R833 had slightly below average mean yield because of its susceptibility to early drought. It can be recommended for marginal areas if sensitivity to early drought can be improved through breeding. Although R830 had low yields, it was the most tolerant to drought. It can be used as a source of drought tolerance in a breeding programme. The factors identified to be significantly correlated to yield were plant height, earlength. spikelets/head, seeds/head. sterile florets/head and kernel weight which varied between genotypes tested. This study showed that. drought tolerant wheat cultivars can be selected more efficiently under mobile rain shelters by drought simulations. The costs incurred and time wasted in travelling from one location to another can significantly reduced by use of rain shelters. They are therefore recormnended for use during drought simulations.
Appears in Collections:Faculty of Agriculture

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