EFFECT OF IRRIGATION AND PLANT CANOPY ARCHITECTURE ON WHITE MOLD DISEASE DEVELOPMENT IN DRY BEAN

Citation

K.A. Kader, P.M. Balasubramanian, and S. Chatterton. Effect of irrigation and plant canopy architecture on white mold disease development in dry bean. Canadian Pulse Research Workshop, Winnipeg MB, October 26 – 28, 2016. (oral presentation)

Abstract

White mold (WM) caused by the fungus, Sclerotinia sclerotiorum, can result in significant yield losses in dry bean (Phaseolus vulgaris L.). Soil moisture levels and microclimate within dry bean canopy are the major contributing factors to WM development. Avoidance of WM development in dry bean due to upright canopy architecture has been documented. In Alberta, all dry bean crops are grown under irrigation which could affect soil moisture and canopy microclimate. Field studies were conducted in 2015 and 2016 at Lethbridge to evaluate levels of irrigation and plant canopy architecture on WM development in dry bean. Three levels of irrigation (high, medium and low) and five cultivars with different canopy architecture (determinate upright bush, indeterminate semi-upright bush and indeterminate prostrate) were arranged in a split plot design experiment. Disease parameters such as ascospore release, percent flower infection, and WM incidence and severity were recorded. Microclimate variables within plant canopy such as leaf wetness, temperature and moisture within 5-cm of top soil, were also recorded. Plant characteristics such as canopy porosity, yield and thousand seed weight were also recorded. Medium irrigation significantly reduced WM, soil moisture in top 5-cm soil and leaf wetness and produced highest yield. Indeterminate semi-upright bush cultivars were able to avoid WM. A cultivar x irrigation interaction was also observed.