Farmers’ preference for onion varieties and implications of knowledge of Iris yellow spot disease in Kenya

Abstract

Thrip transmitted Iris yellow spot disease (IYSD) is an economically important viral disease, affecting bulb onions worldwide. Recommended IYSD resistant varieties are not commonly grown in countries like Kenya, yet inappropriate disease control measures are applied upon disease occurrence in the fields. This is presumably due to lack of knowledge on the disease and/or recommended varieties do not match farmers’ preferred traits. The objective of this study was to assess farmers’ knowledge of IYSD and their criteria for selecting onion varieties for/against IYSD in Kenya. A study was conducted with 360 respondents across three onion growing agro-ecological zones (AEZ) in Kenya, during 2019-2020. Farmers’ fields were assessed for IYSD incidence and severity. All farmers acknowledged the existence of IYSD based on diseased plants in the field. However, majority of the farmers (95.6%) were not aware of the cause of the disease. Onion thrips and IYSD susceptible red onion varieties were the most preferred (77.9%) by farmers. Preference for these varieties was based on their high yielding capacity, early maturity, strong pungency, marketability and long shelf life. Most farmers (59.8%) relied on fungicides to control IYSD, though ineffectively. Lack of appropriate management strategies for IYSD was due to lack of knowledge on the disease diagnosis, epidemiology as well as cultivation of IYSD susceptible red varieties.