Developing Ecofriendly Approach For Management Of Pests And Diseases Of French Beans In Murang’a And Kirinyaga Counties, Central Kenya

ABSTRACT

French bean (Phaseolus vulgaris L.) production areas are in close proximity to Nairobi and around Mount Kenya. These include Kirinyaga, Machakos, Nyeri, Naivasha and Thika. Production of the crop is majorly hampered by pests. To manage these, farmers are known to mainly depend on synthetic pesticides as a sole control measure which at times results to produce exceeding maximum residue limit set by the importing markets. Pesticides leave residues in and on the produce, contaminate soil and waterways, harm non-target organisms and cause general environmental pollution. Economically, the farmers who use pesticides in the production of french beans for export are in danger of losing their market share due to the failure to manage the MRLs. To help safeguard the livelihood of the small scale farmers, this study was carried out to provide the best environmentally responsive approach in managing the French beans pests. The study was carried out at Mwea in Kirinyaga county and Thika in Kiambu county. The treatments included use of selected synthetic pesticides, biological control, and integrated pest management (IPM) comprising of Agronets, biocontrol and monitored pesticide use based on randomized complete block design with four replications. Results show no significant difference across the various management practices in the number of most pests such as Aphids (P=0.125), Thrips (P=0.424) and Bean fly (P=0.725). A significant difference was noted in infestation by whitefly (P=0.002) and Leaf hoppers (P=0.015) among the different treatments, Agronet treated plots recorded the lowest infestation levels (means 14.9a and 1.00a) followed by Biocontrol plots (mean 66.8b) while the control plots recorded highest levels of (mean 91.4b and 10.4b). The yield of the beans from the Agronet plots gave a higher mean yield quantity of (7215g) as compared to the other treatment options Pesticides (5992g) and Biocontrol (5716g). The Agronets plots as well showed lower mean numbers of the bobby beans (989g) as compared to the fine (4708g) and extra fine (1518g) beans.IPM provided effective management of the various pests as it included both the use of biocontrol products and pesticides under Agronet technology. Farmers interviewed on aspects of challenges in adoption of IPM as a pest management strategy showed that majority (58.1%) had not heard about Integated Pest management with those who have heard (41.9%) requesting the need for more information. Of the respondents who had information about IPM only a small group (25%) practiced it while the rest (75%) have not practiced the same. A significant positive correlation (0.545**) was recorded between those farmers who have heard of IPM and those who practice the strategy. Therefore, optimization of the IPM system would be essential for ensuring maximum control of pests’ hence increased French bean production.The study recommends involvement of Government through the various stakeholders to train farmers on IPM, encourage farmers to use simple and less expensive cultural methods in pest management including application of ash to the plant roots, physical removal of infested plant parts among others.