By: Gary Kruger, PAg – Irrigation Agrologist and Barbara Ziesman, AAg – Provincial Specialist, Plant Disease
Sclerotinia sclerotiorum is capable of initiating economically important diseases in many field crops, including canola and lentils. Foliar fungicides are commonly used to manage sclerotinia diseases.
When deciding whether or not to apply a fungicide for the management of sclerotinia diseases, take into consideration the environmental conditions, field history and crop canopy characteristics. Both sclerotinia stem rot of canola and white mould of lentils are highly influenced by the environment, with the risk of disease development being higher when moisture conditions are above normal. The field history and crop canopy characteristics are also known to influence disease risk.
Although the spore stage of the fungus can be wind borne, allowing for spores to move in from other fields, the rotation and disease history within a field will influence the amount of inoculum present within the field to initiate the disease. This is particularly important when the disease can be initiated by both ascospores and mycelia originating from overwintering sclerotia, which is the case for lentils but not canola. The crop canopy characteristics, such as canopy density and the level of lodging, will influence the microclimate under the canopy by either making it more or less favourable for disease development. More detailed information on sclerotinia diseases of field crops can be found the Ministry webpage on Scerotinia.
Under irrigation, the management of sclerotinia diseases may be even more challenging due to more continuous high moisture conditions. The Irrigation Crop Diversification Centre (ICDC), with the assistance of United Agri Products, is initiating a demonstration during 2016 to evaluate the benefit of using Contans for the management of sclerotinia in irrigated fields. Contans is a biological pest control product that infects the Sclerotinia sclerotiorum sclerotia in the soil and prevents their germination. The project will compare Contans to foliar fungicides and a fungicide free check.
For more information, please contact Gary Kruger at firstname.lastname@example.org or 306-867-5524, or Barbara Ziesman at email@example.com or 306-787-4671.