Tar spot distribution Aug. 18, 2021.

Let’s talk about tar spot

OMAFRA Field Crop Report for September 15

Reading Time: 5 minutes There has been considerable discussion around tar spot disease in corn this season and of course many questions as well. Let’s go over some of these questions! Where did Tar Spot common from? In 2015, Tar Spot was confirmed in the Midwest US (Indiana/Illinois) where it was believed to have been blown in from Mexico on […] Read more

Typical N deficiency symptoms in corn – leaf yellowing and senescence along the mid rib in from the leaf tip, starting from older/lower leaves.

What will be the corn N story for 2021?

OMAFRA Field Crop Report for September 1

Reading Time: 4 minutes While the 2021 growing season started dry, regular and often heavy rains started for many areas from Southern to Eastern Ontario from late June through July. Some received well above normal rainfall in July. Naturally, conversations began revolving around “are we losing nitrogen (N)” or “will we need more N on corn?” Optimum N rate […] Read more

Figure 1. Weekly WBC trap catches for Ontario. Peak flight occurred during the week of July 29th to August 4th.

Flight of the western bean cutworm

OMAFRA Field Crop Report for August 25

Reading Time: 2 minutes It is safe to say that western bean cutworm (WBC) is a pest that we can rely on entering corn and dry beans every year in Ontario. Though a frustrating pest to scout for, using traps to monitor moth flight has helped us better predict when to expect peak moth flight occurs, which is shortly […] Read more

Scouting for tar spot.

Update on tar spot in corn

OMAFRA Field Crop Report for August 18

Reading Time: 4 minutes Tar spot in corn was first identified last year in Ontario on September 21, 2020 and confirmed to overwinter in Ontario on July 2, 2021 in West Elgin. Since then, tar spot has been also detected in Essex, Chatham-Kent, Lambton, Middlesex and Norfolk counties as of July 18, 2021 (see below). This was anticipated since […] Read more

Figure 1. An oat cover crop in the fall of 2020 in Waterloo region.

Cover crops for weed management

OMAFRA Field Crop Report for August 4

Reading Time: 3 minutes It’s the time of year when Ontario farmers are turning their attention to seeding cover crops following cereal harvest. Each grower has their own reasons for growing a cover crop – whether it’s to improve organic matter, hold onto nutrients from manure, provide a nitrogen credit or protect against erosion. In this report, we will […] Read more


The seed head of chess grass extending beyond a winter wheat canopy.

Grassy weeds in winter wheat at harvest

OMAFRA Field Crop Report for July 28

Reading Time: 2 minutes Three different types of grassy weeds have been found above the winter wheat canopy at harvest this year. To prevent them from becoming a problem, they need to be identified so that the appropriate management actions can be taken. Here is a breakdown of each grass species and control options. Chess grass (Bromus secalinus) Management: Chess grass […] Read more

Closeup of a plowed field, fertile, black soil.

Revitalizing soil with manure and cover crops after harvesting wheat

OMAFRA Field Crop Report for July 21

Reading Time: 2 minutes Wheat in a crop rotation provides many benefits, including spreading weather risks that can impact yields and balancing workload more evenly between planting and harvest season. Wheat also provides the opportunity to revitalize the soil; to disrupt pest cycles; alleviate compaction and increase subsequent corn and soybean crop yields. Best of all, wheat in rotation […] Read more

Root rot on a dry bean plant.

Root rot, white mould and crop pest insects

OMAFRA Field Crop Report for July 13

Reading Time: 3 minutes There are mixed reports on the health of dry beans in Ontario this season. While many fields look good, rains following the initially dry conditions at planting have increased the incidence of root rots as well as the risk of white mould. Root rot In Ontario, the four main fungal pathogens causing root rot are […] Read more


The main risk is that soybeans planted late will not mature or will be extremely low in yield.

Are double crop soybeans following wheat harvest in your plans?

OMAFRA Field Crop Report for July 7

Reading Time: 3 minutes The unprecedented price of soybeans has fueled considerable interest in double cropping soybeans. As winter wheat comes off there are a number of factors that should be considered. Since half the growing season is over by mid-July double cropping soybeans in Ontario is risky and not covered by crop insurance. Double cropping has been tried numerous times with variable success. The main […] Read more

Figure 1 (left): Thrips are tiny and cigar shaped. Adults have fringed wings while the larva (above) are wingless. Figure 2 (right): Thrips feed on individual plant cells leaving scars along the leaf veins.

Much ado about crop pest insects

OMAFRA Field Crop Report for June 23

Reading Time: 3 minutes It is proving to be another good insect year with several early season pests keeping everyone busy scouting to stay ahead of. Going into July and August, there are a few more pests that we need to keep watch for. Thrips continue to be spotted in soybeans, corn and wheat fields. There are several different kinds […] Read more