Items from Kenya.

ITEMS FROM KENYA

 

NATIONAL PLANT BREEDING RESEARCH CENTRE
Private Bag Njoro, Njoro, Kenya.

Response of bread wheat genotypes to drought simulation under a mobile rain shelter in Kenya. [p. 94]

K. Kimurto, M.G. Kinyua, and J.M. Njoroge.

Development of drought tolerant wheat genotypes for marginal areas of Kenya would enhance utilization of the marginal areas, which comprise 83 % of the total national land area. Simulated drought under a rain shelter provides a good alternative to screening in the semiarid areas, which are vast and widespread. This method excludes rainfall and allows other variables to fluctuate naturally. Moisture regimes simulated included terminal, early, mid and late droughts, and were created under a mobile rain shelter at Njoro, Kenya, in 1998 and 1999. The drought responses of five wheat varieties, Duma, R748, R830, R831, and R833 were determined. Five differing moisture regimes were created under the mobile rain shelter by applying drip water (i) up to seedling stage (70 mm), (ii) through tillering (82 mm), (iii) up to anthesis (94 mm), (iv) up to grain filling (106 mm), and (v) at all stages (118 mm). Data was collected on yield and yield components during the growing season from seedling to maturity. An analysis of variance was made in each season and data from the two seasons were combined. Terminal and early drought caused significant reduction in tiller number and number of reproductive tillers while mid to late droughts caused significant reduction in ear length (16.9 %), spikelets/head (14.3 %), and 1,000-kernel weight (22.4 %), and an increase in the number of sterile florets/head (28.3 %) as compared to the control. Seedling and reproductive stages were the most critical stages for moisture requirement. Genotype R748 performed well in all moisture regimes, and it should be recommended for commercial production in the dryland areas. Selecting drought tolerant cultivars using mobile rain shelters for drought simulation should be possible in Kenya.

 

Developing wheat varieties for the drought-prone areas of Kenya, 1996-99. [p. 94]

M.G. Kinyua, B. Otukho, T.S. Payne, and O.S. Abdalla.

Drought-prone areas in Kenya have recently attracted more attention from both researchers and policy makers. In order to enhance the economic potential of these areas, the development of bread wheat varieties that tolerate drought is being emphasized. Yield trials were carried out from 1996-99 to identify bread wheat genotypes that would perform well in Katumani, Elmentaita, Mogotio, and Lanet, representative dry sites in Kenya. In each year, there were about 14 lines tested in comparison with check varieties Duma and Ngamia. Genotype, genotype x environment, and environmental differences were observed. At the end of the trials, the new wheat variety Chozi was released for commercial production with a yield that ranged from 0.5-2.5 t/ha over years and locations.