Journal Articles

Survey of the incidence and distribution of groundnut rosette disease in major groundnut-producing regions of Western Kenya

Thu, 26 Mar 2026 00:00:00 GMT

Survey of the incidence and distribution of groundnut rosette disease in major groundnut-producing regions of Western Kenya Were, Eric Osewo Groundnut rosette disease (GRD) is the most important viral disease of groundnuts in sub-Saharan Africa. In Kenya, GRD infection especially before flowering results in 100% loss in pod yield. Surveys were conducted in 2016 and 2017 to determine the incidence and distribution of GRD in five major groundnut growing Counties of western Kenya. A structured questionnaire was used to assess GRD incidence and severity and farmers’ awareness about management of GRD. Reverse transcription (RT) polymerase chain reaction (PCR) was used for the detection of GRD agents in collected symptomatic samples. Results revealed that GRD was prevalent in all the fields of the five counties. The highest mean disease incidence was in Busia County (35.7%) while the lowest incidence was in Siaya (23.1%). The most conspicuous symptoms observed in all the fields inspected were yellow/chlorotic rosette and green rosette. The highest mean disease severity was observed in farmers’ fields in Busia (3.1) and Bungoma (3.0) Counties, while the lowest was observed in Siaya (2.8). RT-PCR detected GRD agents in all the symptomatic samples. This study demonstrated the widespread occurrence of GRD in major growing regions of western Kenya and warrants the implementation of effective virus disease control strategies. Key words: Arachis hypogaea L., field survey, groundnut rosette disease, occurrence, severity. MSc Research Publication

EFFICACY OF TAGETES MINUTA AND TITHONIA DIVERSIFOLIA FORMULATIONS AGAINST MELOIDOGYNE INCOGNITA USING A NOVEL RELEASE APPLICATION TECHNIQUE IN TOMATO

Tue, 24 Feb 2026 00:00:00 GMT

EFFICACY OF TAGETES MINUTA AND TITHONIA DIVERSIFOLIA FORMULATIONS AGAINST MELOIDOGYNE INCOGNITA USING A NOVEL RELEASE APPLICATION TECHNIQUE IN TOMATO Macharia, Rachael Muthoni Tomato (Solanum lycopersicum) is an economically important crop in East Africa and is produced largely by small-scale farmers. The root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood, causes serious constraints in tomato production in the African continent. Organic additives of plant origin have been known to control nematodes. The efficacy of different formulations of these additives dispensed as a slow-release in filter bags against M. incognita remains unknown. This study investigated the efficacy of two formulations; powder, and pellet from leaves and stems (above parts) and roots (below parts) of Tithonia diversifolia and Tagetes minuta on M. incognita in tomato. The filter bags were made of non-woven interfacing fusible fabric, and they contained the extracts used in the experiments. The experiment was laid out in a completely randomized design with 18 treatments and replicated four times. Tomato seedlings were inoculated with about 1500 freshly hatched second stage juveniles of M. incognita five days after seedling transplant. Data was collected on root galling, number of egg masses per root, root-knot nematode second-stage juveniles in the soil, and tomato yield and subjected to analysis of variance (ANOVA). Treatment means were compared using the Tukey Studentized Range Test at a 5% probability level (P = 0.05). Results showed that all formulations significantly (P= ˂0.001) reduced nematode populations relative to the untreated control. However, untagged (without filter bag) formulations were about five times better than the tagged (with filter bag) in both the preventive and curative trials at 42- and 84-days post-inoculation (DPI). No significant differences were observed at 126 DPI. Powder formulations of T. minuta roots (79%) and T. diversifolia leaves (78%) significantly (P = ˂0.001) reduced M. incognita juvenile populations followed by pellet formulations of T. minuta leaves (74%) and T. diversifolia roots (72%) relative to the positive control (70%) Bionematon® Powder formulations (79%) reduced RKN populations better than the pellet formulations (73%) but the yield was higher (70.7 t/ha) in the latter. Tagged powder formulations of T. diversifolia roots recorded a 7% decrease in yield in the preventive trial compared to the curative trial. However, within the same trial, tagged pellets of T. minuta roots and the positive control recorded more than 10% increase in yield relative to the curative trial. These findings indicate that formulations of T. minuta and T. diversifolia incorporated in filter bags can be used for management of RKNs in tomato and other vegetable crops. MSc Research Publication

Determinants of finger millet adoption, non-adoption and dis-adoption among smallholder farmers in Nakuru, Kenya

Thu, 13 Nov 2025 00:00:00 GMT

Determinants of finger millet adoption, non-adoption and dis-adoption among smallholder farmers in Nakuru, Kenya Mireri, Richard Nyandigisi Previous studies on technology adoption have treated smallholder farmers’ decisions as being binary. In this article, we assess the adoption, non-adoption and dis-adoptions decisions among smallholder finger millet producers in Nakuru, Kenya. The crop has potential to enhance food security and nutrition in the context of climate change. Data for the study were collected from a household survey of 326 households selected through a multi-stage sampling process. Descriptive and logistic regression analysis was used to analyze the data. The study findings reveal that knowledge levels were higher among the adopters (81.4%), compared to the dis-adopters (45.6%) and non-adopters (58.2%). While attitudes towards finger millet production were generally negative, a large proportion of adopters had positive attitudes towards the economic value of the crop and its contribution to human health. Regression results show that higher levels of knowledge were positively associated with finger millet adoption. As expected, positive attitudes had a positive influence on adoption while concurrently negatively influencing dis-adoption. Further the results suggest that changing attitudes on economic value and the role finger millet plays on human health could improve adoption decisions. The other factors that had a positive influence on adoption were education, income, farming experience, while gender (being female), education (higher), and income had negative influence on dis-adoption. Overall, our results suggest the importance of psychosocial factors (knowledge and attitude), the importance of finger millet to female household heads and resource endowment factors (such as education and income) in sustaining adoption decisions while concurrently dissuading dis-adoption. Keywords: adoption, dis-adoption, non-adoption, attitude, knowledge MSc Research Publication

Evaluation of the Antagonistic Potential of Trichoderma atroviride and Trichoderma harzianum against Fusarium Wilt of Banana (FWB), under in vitro conditions

Wed, 07 May 2025 00:00:00 GMT

Evaluation of the Antagonistic Potential of Trichoderma atroviride and Trichoderma harzianum against Fusarium Wilt of Banana (FWB), under in vitro conditions Wariebi, Alaric Browne Banana (Musa spp.) is the most valued and traded fruit worldwide and is a major food security crop and source of incomes for millions of people in the global south. Fusarium oxysporum f.sp. cubense (Foc), the causal agent of Fusarium wilt of banana (FWB) is the most prominent threat and devastating disease of banana, posing a serious threat to global banana trade. Trichoderma species are renowned biocontrol agents of many phytopathogens, showing encouraging results in vitro. This study was conducted to assess the antagonistic and biocontrol potentials and mechanisms of mycoparasitism of Trichoderma atroviride and Trichoderma harzianum against Foc. The Dual culture technique and culture filtrates were used to evaluate the efficacy of both Trichoderma species against Foc. Mycoparasitism of Trichoderma against Foc were determined by observing a mixture of both fungal species taken from a 14-days old dual culture. The mixture was observed under a simple light microscope. The means of both in vitro tests was analysed in GenStat software, 14th edition (p<0.05). Dual culture and culture filtrates of T. atroviride inhibited the mycelial growth of Foc by 60.56% and 65.33%, respectively. Consequently, T. harzianum exhibited 64.21% and 61.75% inhibition of Foc. As per Bell’s Degree of Antagonism, both Trichoderma species were highly antagonistic against Foc after seven days. Both species demonstrated coiling, lysis, penetration and winding as mycoparasitism. The results show that T. atroviride is a promising biocontrol agent and can be used alongside T. harzianum in the management of Fusarium wilt of banana. Keywords: Dual culture, Fusarium oxysporum f.sp. cubense (Foc), Fusarium Wilt of Banana (FWB), Mycoparasitism, Trichoderma species, Trichoderma atroviride International Journal of Advanced Multidisciplinary Research and Studies