A Survey of farmers’ perceptions and management strategies of the sweet potato weevil in Homa Bay County, Kenya

Abstract

Sweet potato (Ipomoea batatas L.) is one of the most widely grown root crops worldwide. In Africa, it is grown in small plots by poorer farmers. Production of the crop is extremely low in Kenya as compared to other African countries due to the existence of common insect pests. Sweet potato weevil (Cylas spp.) is known as the biggest pit fall for production and productivity of the crop in the country. This study sought to determine the opinion of sweet potato farmers concerning sweet potato resistance to Cylas spp. and determine control strategies employed by sweet potato farmers in managing the pest. The study also sought to determine the sweet potato production constraints faced by the farmers in Homa Bay County, Kenya. The study was conducted using a Participatory Rural Appraisal approach in which 269 farmers in the County were interviewed on the sweet potato varieties with field resistance to Cylas spp., the crops' production constraints (with emphasis on damage by Cylas spp.) and farmers' control strategies in regard to the weevil. Data were also collected from the farmers whose sample size was determined using the table on sample size selection and standardization equation. Data were analysed using descriptive statistical techniques that were frequencies, percentages and standard errors. The study established that majority of the farmers from Rachuonyo (89.7%) and Ndhiwa (91.9%) were not aware of any variety that had field resistance to Cylas spp. However, 10.5% of the farmers in Rachuonyo and 8.1% of the farmers in Ndhiwa identified nine varieties which have shown relative field resistance to root damage by Cylas spp. The varieties that were identified to be resistant to Cylas spp. by farmers in Rachuonyo were Kalamb Nyerere, Tombra, Sinia, Odinga, Kemb 10, Wera and Zapallo. However, the varieties that were identified to be resistant to Cylas spp. by farmers in Ndhiwa were Amina, Mugande and Ndege Oyiejo. Further, the findings revealed that Cylas spp. was the most problematic pest by 90.3% and 96.8% of households in Rachuonyo and Ndhiwa, respectively. Majority (64.5%) of the farmers in Ndhiwa did not use any methods to manage Cylas spp. However, farmers in Rachuonyo (26.2%) and Ndhiwa (15.3%) preferred re-ridging during weeding as a management strategy in regard to Cylas spp. These findings reiterate the importance of the sweet potato weevil in rural sweet potato farming systems and thus innovative management strategies are necessary.

Determination of Effectiveness and Efficiency of Production Factors in Sweet Potato Farming in Lamongan, Indonesia

“…The increase in the use of one or more new superior types by 21 percent shows that increased technology adoption using sweet potato varieties is still low [19]. In developing countries, sweet potatoes are the sixth major food crop globally, rice, wheat, potatoes, corn, and cassava [20]. Sweet potatoes have become a cashgenerating commodity for Odisha farmers, but there are no particular sellers of these commodities.…”

The Independent Biological Activity of Bacillus thuringiensis Cry23Aa Protein Against Cylas puncticollis

“…The egg-laying, larval development, and feeding Cylas larvae occur inside the sweet potatoes, which is unavailable for insecticides dispersed on the surface of sweet potatoes. Many strategies have been developed for the management of this pest including; cultural methods such as clean planting vines, crop rotation, early planting, and harvesting ( Ochieng et al, 2017 ), mass trapping using sex pheromones ( Smit et al, 1997 ; Downham et al, 2001 ; Reddy et al, 2014a ), breeding the resistance cultivars of I. batatas ( Stevenson et al, 2009 ; Anyanga et al, 2013 ; Ochieng et al, 2017 ), fumigants and chemical control ( Hwang, 2000 ), and phytosanitary treatment by X-ray irradiation ( Follett, 2006 ). Amongst all the management approaches, biological control focusing on soil inhabitant insect pathogens; fungi, bacteria, and nematode have better effectiveness in controlling Cylas spp.…”