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OMAFRA: Watch out for these pests and diseases in your crops

July 4, 2023  By Field Crop News

It’s time to keep an eye out for tar spot! If 2023 goes the way of the past two years, tar spot will most likely be confirmed in southwest Ontario during the first two weeks of July. Farmers, consultants, agribusinesses and others are encouraged to scout for the disease and be aware of reports of tar spot in the province.

As of June 28, tar spot has been detected in Iowa, Missouri and Kansas. The drought conditions in states such as Michigan, Indiana, Illinois and Wisconsin which have potential to impact Ontario’s risk to the disease has been very dry but the most recent rain in these areas will help the crops but likely tar spot as well. The fungus which causes tar spot favours dry and wet environmental cycles like those we have had in the southwest the past few weeks. |READ MORE

As of June 20, true armyworm has been spotted at near threshold levels in a winter wheat field near Niagara and has also caused significant damage in late planted seedling corn in Chatham Kent. Though most of our yield enhancement network (YEN) wheat sites being scouted weekly have picked up only low levels of true armyworm in a few of the sites, it would be worth scouting both winter and spring wheat fields as well as other at risk crops these next few weeks. At risk crops include wheat, mixed forages and corn before V6 stage.


Cereal leaf beetle is also present at low levels in winter and spring wheat fields with the exception of a couple of fields that required management in the last week. While you are scouting for true armyworm, be on the lookout for cereal leaf beetle too. In winter wheat, control is only warranted if feeding is taking place on the flag leaf in the early heading stages. In spring cereals, control is warranted if an average of three larvae per tiller are found before boot stage. One cereal leaf beetle adult or larvae per stem warrants control after boot but prior to heading. |READ MORE


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