Prevalence, epidemiology and management of bean scab (Elsinoë phaseoli) of common beans (Phaseolus vulgaris) in Kenya

Kenya Agricultural & Livestock Research Organization (KALRO), Kakamega, Kenya

Mr Yona Masheti

KT PhD Scholar

PhD, Crop Protection, University of Nairobi, Kenya, 2019- 2023

Supervisors: Professor James W. Muthomi (University of Nairobi, Kenya),Professor William Maina Muiru , Professor Paul Gepts (University of California, Davis), Dr Esther Arunga (University of Embu, Kenya).

Mr Yona Masheti

PROJECT OVERVIEW

Background

Bean scab threatens to become a major biotic constraint for Kenyan bean producers. Although reputed to have caused major losses in yield, the disease (causative fungus Elsinoë phaseoli) is as yet poorly understood.

Objectives

To determine the prevalence and variants of Elsinoë phaseoli in Kenya.
To establish the environmental conditions that affect the incidence of bean scab.
To identify appropriate management options for bean scab.

Progress to date

The occurrence of scab was assessed in farmers’ fields in major bean growing zones. Sampling has been completed in 14 of the 22 target counties.
Disease management options used in the control on bean scab farmers in Kenya have been assessed. Rodazim, a fungicide of the group of benzimidazoles, contains carbendazim, an active ingredient effective against scab.
The assessment of the phenotypic characteristics of Elsinoë phaseoli in Kenya is underway.

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Map with the locations of field sampling for bean scab (i); bean scab damage on the upper side of infected leaves (ii); lower side of infected leaves (iii); pods (iv); bean scab isolates grown in culture (v).