What once appeared to be an early spring has gradually shifted to a more normal planting season across most of southern Ontario. At the bi-weekly meeting of certified crop advisors (CCAs) and provincial ag ministry personnel in Exeter, there was notable relief coming from reports of the percentages of corn and soybeans planted since the previous meeting on April 17.
Across much of the Huron-Perth, Middlesex-Elgin-Oxford, Lambton and Norfolk regions, corn planting was reported to be in a general range of 50 to 60 per cent, with as much as 90 per cent complete in Oxford and in parts of central Huron. Soybeans are just getting started, with the majority of reports citing levels of five to 10 per cent.
Also cause for some relief was the timely arrival of soaking rains across much of the province. Most reports from CCAs ranged between a third and a half-inch, with some recording up to seven-10ths of an inch. Weather forecasts across most of southern Ontario for the coming week call for temperatures in the mid-20s, meaning growers will be eager to get the rest of their corn in and move on to their soybean ground. Of course, all of that will depend on if and when the rains begin to fall again, this week.
If there was a concern on the minds of CCAs, it was the level of damage done by a series of cold nights, particularly April 27 to 28. Temperatures in some districts fell as low as -8 C, for more than four hours, which is beyond the conventional duration thought to cause significant damage in a number of crops.
Anecdotally, a corn field between Fergus and Guelph suffered an almost complete loss because of the frost; seedlings were found frozen in the ground, making the field a prime candidate for replanting. The prospect for replanting with corn however, is limited, given the shortage of seed in most of the preferred hybrids. As such, any frost damage on corn at this point is likely to lead to a switch to soybeans.
Wheat fields were also damaged by the frost, although provincial cereal specialist Peter Johnson suggested the damage was not as severe as anticipated.
One advisor asked about the prospect for disease spread in wheat that was burned by nitrogen applications followed by frost. Johnson replied that once the tissue in the leaf tips is dead, disease pathogens have little point of entry; they require green tissue for entry. However, he added, conditions are certain to change with the onset of warmer temperatures, meaning closer monitoring in the weeks to come.
The other crop hurt by the frost was alfalfa, and again, the damage was not as substantial as conventional thinking would suggest. Stems can be kinked by the frost, and new leaf growth may appear yellowed or discoloured, but as long as the head remains undamaged, the plant should be viable and the crop should survive.
Weeds held back
The cold temperatures formed much of the focus of the meeting’s proceedings, actually. Many advisors find red clover is withstanding cooler temperatures, and weeds are not advancing as much, although that is also likely to change once the warmer temperatures arrive later in the week.
Soybeans, long thought to be sensitive to nighttime temperatures and cold-water imbibition, are showing signs of competing well in less-than-ideal conditions. Provincial soybean specialist Horst Bohner spoke of planting one field during the night, just to see what might happen, and it reportedly fared every bit as well as one planted during the afternoon hours.
On the weed side of the proceedings, although temperatures have managed to hold down many of the species, particularly in wheat fields, there are signs of lamb’s quarters in many fields. Johnson noted that most plants have been stunted by the cold, to the point where the growing wheat plants are out-competing the weeds. But lamb’s quarters will continue to emerge, as will pigweed, and although it may be too late for some to consider a herbicide application on its own, growers can certainly tank-mix it with a fungicide.
The other concern in wheat fields across Ontario is the dandelion situation. For most fields, it’s now too late to kill dandelion, even with Estaprop. One management practice put forth on Tuesday was to apply Classic on soybeans later this fall, to control dandelion next spring. The same strategy with Refine, even at half-rate in the fall, will mean little or no chickweed the following spring. And, it can be applied on emerged wheat.
— Ralph Pearce is a field editor for Country Guide at St. Marys, Ont.