Disease Management in Winter and Spring Cereal Crops

The disease pressure in cereals has been quite minimal to date due to the cool conditions cereals have experienced so far. However, as temperatures begin to rise and canopies get thicker producers should be on the lookout for those important cereal diseases in both your winter and spring cereal crops.  Here are a few key diseases to watch for.

 

 

Powery mildew is a disease that can cause issues in both wheat and barley. It likes lots of humidity as well as temperatures between 15-20°C. There have been some early reports of this disease in May in Huron and Perth counties. If the crop is at or approaching flag leaf, a fungicide application should be considered if the variety is susceptible and there are symptoms on the flag leaf and the second leaf (3-5%). If the forecast is for temperatures above 25°C and conditions are dry, a fungicide may not be necessary.

 

 

Septoria leaf spot is another early season disease in Ontario which thrives in prolonged wet conditions especially in May and early June. This disease can be controlled with timely fungicide applications. An application may be warranted if the variety is susceptible and if there are lesions on the second to last leaf up to the boot stage, or when there is a lesion on the flag leaf at head emergence.

 

 

Stripe rust (figure 1) can impact wheat, rye and barley. It has been a disease that Ontario producers have experienced more in recent years.  However, looking back on previous years when there were high levels of infection, the disease was found in Ontario early in May. To date the disease has not yet been identified here this year and we continue to monitor its movement south of the border. Stripe rust likes temperatures ranging from 12-21°C and can be identified by small yellow-orange lesions that merge to form stripes on the leaves of plants.  Only in severe cases will it impact the head and VERY rarely does it effect the stems.  Control of this disease is warranted when a susceptible variety is being grown and 1% of the flag leaf is affected and rainy, wet weather is in the forecast.