Browsing by Author "Mogaka M. Onyambu"

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Occurrence Of Bacterial Wilt Pathogen In Soils And Potato Tubers In Runyenjes In Embu County, Kenya.
(Research journali, 2021-04) Ong’au, Peterson M.; Muraya M., Moses; Onyango O., Benson; Mogaka M. Onyambu; Ogolla O., Fredrick; ; ;
Potato (Solanum tuberosum L.) is a starchy tuber crop that is widely cultivated in Africa as an income generator. Nutritionally, potato provides essential amino acids among other important body required nutrients. Despite the significance of potato as a crop, its production is constrained by various biotic and abiotic factors, which includes bacterial wilt caused by Ralstonia solanacearum. Ralstonia solanacearum is widely distributed in tropical, sub-tropical and warm temperate climates with a wide host range. In Kenya, the infection of potato farms by R. solanacearum has spread to all potato growing areas. It affects over 70% of potato farms causing yield losses of between 50 to 100% in Kenya. This study was carried out to assess the occurrence of bacteria wilt in small scale farmer’s potato farms in Runyejes in Embu County. A survey of potato farms was conducted in different tomato growing villages in between September and October 2019. Diseased potato samples and soil samples were collected from the farms and taken for laboratory study at Chuka University. Collected data on incidence of pathogen on tuber and soil were subjected to one way analysis of variance (ANOVA) in SAS version 9.4. Significance means of all the analysis were separated using Least Significance Difference at α = 0.05. Incidences of potato bacteria wilt disease in different villages surveyed was significantly different (p < 0.05). The incidence of R. Solanacearum in farmer’s fields ranged from 16.51% (Makutano village) to 50.42% (Kiangodu village). The overall mean score for the incidence was 32.2% across all the farms studied. In conclusion, incidence of bacterial wilt pathogen in soil and tuber sampled from Runyenjes area of Embu County differ from farm to farm and location to location. Study on incidence of potato bacterial wilt in is necessary in all small potato farmers in Embu County to determine the extent of spread of the disease in the area.
Prevalence of banana Xanthomonas wilt in Nithi, Tharaka-Nithi County in Kenya
(Journal BiNET, 2021-05-30) Mogaka M. Onyambu; Benson O. Onyango; Moses M. Muraya; Peterson M. Ong’au; Fredrick O. Ogolla; ; ;
Banana (Musa spp.) is a nutrient rich crop grown in small and large scale across the globe. It is rich in carbohydrates, vitamins and minerals thus, it may serve as the source of nutrition in low resourced regions such as Tharaka Nithi County, Kenya. However, banana production in many areas is faced with biotic constraints such as banana Xanthomonas wilt (BXW) disease caused by Xanthomonas campestris pv. musacearum. The pathogen attacks photosynthetic leaves and young fruits, reducing palatability and marketability. There is currently scanty information on prevalence of BXW in Nithi region of Tharaka Nithi County. Additionally, it remains unclear whether farmers in the region are knowledgeable on occurrence of BXW disease, symptoms and management practices. The prevalence of BXW was assessed through survey method in five villages (Kiang’ondu, Marima, Mitheru, Kibumbu and Giampampo) in Nithi. Percentage BXW prevalence in the studied villages was not significantly different (p>0.05). However, slightly higher BXW prevalence value of 21.14% was recorded at Giampampo village and was lower at Mitheru 11.24%. There was significant relationship (X2 (8, N = 46) = 19.93, p= 0.0034) between banana variety grown and occurrence of banana diseases. There was significant relationship (X2 (8, N = 46) = 31.165, p = 0.0053) between banana variety grown and susceptibility to diseases. The relationship between years of growing banana in the same farm and occurrence of banana diseases was significant (X2(6,N= 46) = 8.761,p= <0.0001. The relationship between occurrence of banana diseases and season of the year was significant (X2(8,N= 46) = 32.4591, p= <0.0001). The relationship between occurrence of banana diseases and management option in Nithi was significant (X2(4,N= 46) = 6.9758,p= 0.0025). Majority of the farmers (92%) were unaware of existence of BXW in the region. Farmers expressed lack of knowledge on managing BXW diseases in their banana farms with the majority not being able to identify common diseases of banana. Based on these observations, there is need to educate farmers on best banana farming practices, disease identification and management.