Ontario Field Crop Report: Dryness Causing Some Issues with Soy Emergence

Ontario crops are in generally good condition, although recent dryness has caused some problems with soybean emergence and the effectiveness of pre-emergent herbicides, according to the latest Ontario field crop report, released on Thursday.
Meanwhile, some winter wheat crops are beginning to head out.

Corn

Depending on planting date, corn is at the spike to 5 leaf stage and progressing well with the warm weather. Most corn acres received adequate rainfall for good emergence and an acceptable stand. However, dry conditions have prevented activation of pre-emergence herbicides on many acres. The high heat in the past week has caused weeds to grow quickly, so scouting to stay on top of weeds is important at this time.
In areas of the Niagara Peninsula with clay soils, patches of corn fields are leafing out underground. Planting occurred when the soil was dry on top but “gummy” underneath, and was followed by cold rain and cool temperatures.

Soybeans

Soybean planting is essentially complete, and while emergence is generally good there are some imperfect stands. Similar to last year, lack of rain in recent weeks is causing poor emergence and some acres are being replanted. Some fields planted just before the cold rain on May 13 -14 especially on lighter soils and worked ground have suffered from reduced emergence.

Again, there are concerns with activation of pre-emergence herbicides. Weeds have emerged before rains activated soil applied products, and re-spraying is required to control those emerged weeds. There have been reports of seed corn maggot feeding, especially where soybeans were planted into cereal rye or winter cover crops.

Winter wheat

Wheat is beginning to head out across the province and although it may be a bit short in stature, plants are bushy with a lot of tillers. There are reports of stripe rust in some areas of the province, particularly on fields that did not receive a fungicide application.
Although there has been a lack of rain, there is still a lot of moisture in the wheat canopy and therefore high potential for disease development.  Much of the fungicide application for Fusarium control will happen in the next week. There are also some minor reports of wheat streak mosaic and spindle streak mosaic virus, which looks similar to stripe rust. Cereal leaf beetle has been detected at threshold levels in traditional problem areas such as Alliston. The pest is appearing a bit earlier than expected.