Abstract

Stem rust (Puccinia graminis f.sp.tritici) is a major disease of wheat that occurs more in the main wheat growing regions of Kenya. The objective of this study was to assess the incidence and severity of wheat stem rust during the 2015 growing season. A survey was conducted in Mau-Narok, Njoro and Kabatini regions. During the survey work, 149 small scale wheat growers’ fields were assessed. The results revealed that stem rust incidence of the three surveyed areas ranged from 11.3 to 77.8% and severity 20 to 60%. The survey confirmed that the incidence and severity were associated with the farming practices such as chemical control, varieties grown, use of certified or uncertified seed and cropping systems. The survey showed that high to moderate incidence and severity levels were found on fields with one or two sprays with a fungicide. The use of fungicide was the major practice by growers for stem rust control reporting Mau-Narok with 43.2%, Kabatini 38.9% and Njoro 17.8%. The varieties grown had a relationship to disease incidence and severity percent levels. The use of uncertified seed by farmers contributed to high disease incidence. About 50.6% growers preferred old varieties mainly Robin and NjoroBWII. About 97.8% of the farmers practiced crop rotation of wheat with legumes. A multi-tactic disease management approach mainly two fungicide sprays per growing season, use at recommended rates, planting of certified seed of resistant varieties and crop rotation of legumes with wheat are required as stem rust effective management strategies.

Key words: Wheat production, farm classifications, disease assessment, survey.