Assessment of onion farming practices and purple blotch disease knowledge among farmers in varied agro-ecological zones of Nyeri County, Kenya

Onion (Allium cepa L.) is the second most produced vegetable globally, following tomato and plays a vital role in both cuisines and daily diets. However, the threat of diseases, such as purple blotch caused by Alternaria porri, poses a substantial risk to onion production, particularly in Nyeri County, Kenya. Despite its critical impact on farming, there is a lack of information on farmers' knowledge of purple blotch in this region. This study aimed to assess the onion farming practices and farmers' understanding of purple blotch disease across various agro-ecological zones (AEZs) in Nyeri County. Specifically, the study examines farmers' demographics, cultivated onion varieties, and their knowledge of purple blotch disease. Farms were selected using cluster random sampling. Data were collected from 100 onion farmers through semi-structured questionnaires, and statistical analysis was performed using the chi-square test in Scientific Analysis System (SAS) version 9.4 at α=0.05. The findings revealed that while the Rucet F1 onion variety was popular among the farmers (52%), there is no significant association (X2 (6, 100) = 11.947, p = 0.063) between the choice of variety and AEZs. Similarly, the preferred source of onion seeds, mainly Agroshop (84%), showed insignificant association (X2 (9, 100) = 7.153, p = 0.621) with AEZs. Despite 65% of farmers reporting knowledge about onion diseases, there is no significant association (p > 0.05) between their awareness of purple blotch and AEZs. In conclusion, the study highlights a significant gap in farmers' understanding of purple blotch disease, emphasizing the need for training programs to enhance disease identification skills. Early detection can empower farmers to implement proactive measures, ultimately improving onion productivity. This study recommends diversifying onion varieties for disease resilience, promoting awareness and training on purple blotch identification, engaging women and youths in farming, and fostering collaborative networks for ongoing knowledge exchange and improvement in onion cultivation in Nyeri County.