Ontario Field Crop Report – Week of June 17th, 2019


Grain corn planting is largely wrapped up. Depending on the region, anywhere from less than 10% (heavy clays) to 90%+ of intended corn acres have been planted. There were a small number of growers in higher heat unit regions intending to plant final fields of grain corn before the forecasted rain on Thursday, June 20th. There is also still some silage corn to be planted.

Most corn is at the 3-4 leaf stage, with earliest planted fields at 7-8 leaves and fields planted in the past couple of weeks just emerging. For the more advanced corn, nitrogen side-dressing has begun in the southwest. Emergence has been slower than normal this year due to below average soil temperatures. To date, emergence and uniformity have largely been decent; however, uneven stands are starting to be observed in corn planted 3-4 weeks ago in marginal conditions.  


Planting progress on soybeans ranges from <20% on clays to 100% on light-textured soils. Overall, progress on intended soybeans acres is between 40 and 60%. Soybean stage ranges from just emerging to first trifoliate (V1). Crusting has been minimal due to regular rainfall. Some emergence issues have been noted due to tight soils and less than ideal seeding conditions. The presence of seed corn maggot in some soybean fields has been observed – scout if possible, especially in fields at higher risk.

Seeding rates at this point in June should be increased by 20% relative to a May seeding date to help compensate for plants with fewer pods. Growers intending to plant wheat in the fall may want to reduce maturity to ensure timely planting. 

Unfavourable weather prior to this week delayed spraying and in some cases shifted growers from pre-emergence to post-emergence herbicide programs. For those growing IP soybeans, correct post-emerge spray timing is critical – herbicide efficacy is greatly reduced if weeds become too large.

Given the late season and the presence of sensitive crops in some regions, following good herbicide stewardship practices will be important in the coming weeks. Consider wind speed, application volume, ground speed and neighbouring crops.


Spring cereal stands are generally in good shape and progressing well with the below-average temperatures.

The risk for fusarium head blight in winter wheat remains high. The most advanced fields in Essex and Kent counties were at T3 fungicide timing last week and many received applications. The wheat crop is still progressing slower than normal, but many areas are now at or quickly approaching T3 fungicide timing.

Once 75% of the heads on the main stem reach GS59 (head emergence complete) this is known as “day 0”. Optimum fungicide application timing is on “day 2” when pollination begins, and anthers are visible on the middle of the wheat head. Timing in many stands will be difficult due to lack of uniformity. While day 2 is the optimum time, T3 fungicides can be applied up to day 6 with good efficacy. Therefore, waiting an extra day or two and targeting day 3-6 may enable application for more of the crop at the optimum time. Two fungicide applications are not recommended as they are generally not economical, particularly in those fields with low yield potential. 

Cereal leaf beetle (CLB) is being reported in several winter wheat fields and will likely begin to move into spring cereal stands. If the crop is after the boot stage but prior to heading the threshold is one CLB larva or adult per stem. Watch for pre-harvest intervals if timing is getting late. 

Aphids are also being reported in winter wheat fields. Thresholds are up to the boot stage; if the crop is beyond this stage, treatment has no merit. Populations may begin to increase in spring cereals, however, natural enemies will hopefully build up before that. If young plants have 12-15 aphids per stem up to boot stage and natural enemies are not present, control may be warranted.

Edible Beans

Significant edible bean planting has occurred this week. Some areas have 50-75% of intended acres planted. Cranberry beans have the shortest maturity and should be seeded last. Crusting is a concern in some edible bean fields, given the challenging soil conditions. Edible beans are generally more sensitive to cool, wet planting conditions than corn and soybeans.


Canola is no longer being seeded. Canola planted in northern Ontario is around the 2-3 leaf stage. Flea beetle control has been warranted in some fields. Swede midge are also emerging – traps should be set in fields and monitored every few days while the crop remains susceptible (up to the bolt stage).


Harvest of first cut hay continues throughout the province (Figure 1). Much of the crop is being taken as haylage, due to insufficient drying days. Quantity ranges from average to below average. Quality is still largely unknown. Some livestock producers continued planting silage corn earlier this week to boost forage inventories. Producers who have established alternative forage crops are reminded that it is generally 45-60 days from planting to harvest, depending on the crop.

Figure 1. Hay field in Perth County on Wednesday, June 19th.

Figure 1. Hay field in Perth County on Wednesday, June 19th.

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