Some Breathing Room for Ontario Crops, but Rain Still Needed

Well-received rains moved across much of the province this past week, although some dry patches remain, according to the latest update from Grain Farmers of Ontario on Tuesday. 

Moderate summer temperatures and scattered rains have bought some acres a bit of breathing room, the report said, but rains will still be needed regularly to keep grain filling in western Ontario. Soybeans are turning early this year in areas of drought stress, it added.  

Corn 

The earliest corn in southwestern Ontario is starting to form a visible milk line as it hits the dent stage (R5), while many other later pollinated hybrids are in the early dent stage this week. September will see rapid movement of the milk line as the corn plant closes in on physiological maturity (black layer). This is the critical grain fill period for the corn crop when the plant focuses all its energy on filling the kernel. The depth and weight of kernel will be determined over the next three weeks. Maximum sunlight (solar radiation) and adequate rainfall (moisture) will provide the crop with the best opportunity to fill the kernels with starch. 

However, looking at the two-week forecast for much of Ontario, it will be dry.  

“This will really put stress on plants and cause them to shut down earlier and limit grain fill. In some cases, plants will brown and look dry, but maturity or milk line will not reach full maturity,” the report said. 

Soybeans 

Soybean pods continue to fill this week, with many fields reaching the R6 (Full Seed) stage of development. Any stress at this point of the season will prompt the smaller pods to be dropped from the plant as the plant’s main goal is to fill the current pods so that excess pods will be lost during periods of stress rather than continue seed formation. Not all is lost, as having limited pods and seed will mean that if rain does come in a timely, the plant will continue to fill the remaining seeds, and the seed size will be larger. 

Soon, especially in shorter-day soybeans, R7 (beginning maturity – when one pod on the stem has reached mature pod colour) will be reached. The change from R6 to R7 can span roughly 9 to 30 days, depending on the weather and other factors affecting the plant. 

With a full moon having passed a couple of weeks ago, it allows some in higher elevations and more northern locations to breathe a small sigh of relief, as heavy frosts should still be a few weeks away, as September 10 is the next full moon.