Beans In Kenya Research Articles

A cost benefit analysisof farmer based seed production for common bean in Kenya

Community based informal seed production has recently gained popularity as an alternative to the formal seed sector of disseminating new crop varieties including the common bean. This is because farmer produced seed is readily available and is more affordable by most farmers than certified seed. This study examined the profitability of farmer based common bean seed production in Kenya. The study used data collected from farmers and one seed company participating in seed multiplication. The principal finding was that farmer based common bean seed production was a profitable enterprise and was less sensitive to price fluctuations. Compared to certified common bean seed production, net profit margins were five times higher for certified common bean seed than for farmer based common bean seed production. With the current varieties, profitability depends on access to irrigation and good agronomy.

Occurrence and Severity of Angular Leaf Spot of Common Bean in Kenya as Influenced by Geographical Location, Altitude and Agroecological Zones

Occurrence and Severity of Angular Leaf Spot of Common Bean in Kenya as Influenced by Geographical Location, Altitude and Agroecological Zones

Plant parasitic nematodes associated with common bean in Kenya and the effect of Meloidogyne infection on bean nodulation

Plant parasitic nematodes associated with common bean in Kenya and the effect of Meloidogyne infection on bean nodulation

Modelling the intercropping of maize and beans in Kenya

Intercropping is a common practice on small farms in developing countries. In Kenya, where maize is the staple food, it is common to find maize intercropped with a range of short-term crops such as beans, sunflower, groundnuts, millet, potatoes. Competition between the crops for light, water and nutrients is possible at some stage in the production cycle, and field trials to measure the benefits of intercropping have been inconclusive. SODCOM has been used to analyse the intercropping of maize ( Zea mays) and beans ( Phaseolus vulgaris) in the Kitale region of Kenya. Three cropping situations have been examined: maize alone, beans alone and maize intercropped with beans. The model incorporates modifications which take account of the competition between the intercrops for light and water. The predictions of intercropped yield from the model are found to be in reasonable agreement with the results of field trials among small farmers in the Trans Nzoia District of Kenya over a period of 7 years. Comparing the yields obtained under intercropping with what would have been obtained with both crops grown in pure stands, intercropping has only a minimal effect on the yields of either crop. The yield of the maize, which has a longer growing season than the beans, was found to be sensitive to the degree of moisture stress, which was likely to occur towards the end of the growing season. The main argument against intercropping is that it limits the opportunities for mechanisation beyond seed bed preparation and drilling.

Species range and abundance of insect predators of the bean aphid, Aphis fabae Scop. (Homoptera: Aphididae) on common beans in Kenya

The diversity and abundance of insect predators of the bean aphid, Aphis fabae Scop. (Homoptera: Aphididae) on common beans, Phaseolus vulgaris L., were evaluated in Central Kenya. Predators included species in the Orders Coleoptera, Diptera, Hemiptera and Neuroptera. Coccinellidae were the most abundant and diverse group and several species, such as Hippodamia variegata Goeze and Platynaspis capicola Crotch, had hitherto not been recorded on common beans in Kenya. Higher numbers of predators developed on beans during the short rains (up to 540/100 m2 plot) as compared to the long rain season (182/plot) of 1985. In both seasons, numbers of coccinellid larvae were high after the fourth week of bean growth. The study provides evidence of an important build-up of insect predators on beans.

Effect of intercropping beans with maize on the severity of angular leaf spot of beans in Kenya

Angular leaf spot severity was evaluated on Phaseolus beans which had been planted alone (monocrop) and also simultaneously with maize (intercrop) at Kabete, Kenya, in November 1986 (short rains), and at Kabete and Thika in April 1987 (long rains). Intercropping reduced the area under the disease progress curve (AUDPC) in the short rains at Kabete and at Thika in the long rains by 23–33% at bean: maize proportions of 2:1 for some leaf positions, but did not reduce AUDPC significantly at Kabete in the long rains. Additional treatments to evaluate bean density and planting pattern (row against random) conducted in the short rains had no effect on AUDPC, although disease was reduced by 12–17% at higher bean densities when maize was not present. Fertilization increased AUDPC by 135–205% in the long rains at both sites. Microclimatological observations made at Kabete during the long rains indicated reductions in leaf temperature and air temperature, and increases in relative humidity, in most plots. These changes were small, averaging 0·6°C, 0·2°C, and 1·8%, respectively. Wind velocity was reduced by 55–63% in the intercrop in relation to the monocrop. The results reflect the variable response of angular leaf spot to maize intercrops seen in other studies.

Diversity of food beans in Kenya

In order to have the consumers’ preferences in Kenya in beans (Phaseolus vulgaris L.) more clearly outlined and to survey the variation existing in local food bean material, 997 seed samples from plants selected in farmers’ fields and from agricultural shows were investigated and classified on the basis of colour, size and shape. For the classification a new number system was used to enable easy data transfer to punch cards. This exercise was primarily carried out to aid in setting the goals for a breeding and selection programme. Of the 997 samples the ten most common types were identified, and among those the Rose cocos occurred most frequently with 36.5%, second were the Canadian wonder types with 13.1%, followed by a Red haricot with 9.2%, Mwezi moja with 9.0% and Mwitemania with 2.4%. The types differed considerably, indicating that consumers’ preferences are very flexible. Personal communications lead to the same conclusion. Therefore a breeding and selection programme has, within certain wide limits, allowance to rank characters like disease and drought resistance higher in importance than seed type.