Staying ahead of weeds poses a big challenge

It’s often been said that there are only two certainties in life—death and taxes. But upon closer examination, a third unwelcome reality inevitably springs to life every year. Literally.
Weeds have been a part of agricultural reality for as long as mankind has turned its hand to tilling the soil. There even are references in the Bible assuring their continuity.
Here in Rainy River District, we are no more immune to this immutable fact than those elsewhere, as any farmer or gardener can affirm. However, because of our unique location and climate, the situation here is slightly different from elsewhere in the province.
Because of that, the Ministry of Agriculture and Food sent a weed management and field crop technology specialist from the University of Guelph to the district last week to check out the pastures and crops.
Mike Cowbrough spent most of last Wednesday touring several pastures and fields in the west end, as well as the trials currently underway at the Emo agricultural research station.
What he found was both familiar and unique compared to what he normally sees in southern Ontario.
Because of the weather we’ve had this spring and early summer, Cowbrough found a different situation here.
“The crops [here] are off to a slow start and weeds generally thrive in cool, wet conditions, so they’re doing nicely” he observed.
In southern Ontario, however, spring came early and was quite dry—creating a different set of circumstances. Consequently, there are different weeds with which to contend there.
But that doesn’t mean things are necessarily better down there because weeds are extremely robust and adaptive.
“Weeds aren’t stupid,” Cowbrough noted. “They’ve been around for thousands of years and they’re extremely opportunistic. They are able to exploit the situations in which they find themselves.
“By and large, we’re seeing more weed growth across the province,” he remarked.
Cowbrough did notice a considerable amount of commonality in the weeds plaguing farmers here and those in southern Ontario.
He said roughly 90 percent of the weeds he was able to identify here also are found down south, but there are a few here that are more common to the Prairies than the rest of Ontario.
For instance, he found more buttercups and oxide daisies here. These plants are undesirable because they tend to choke out other grasses and legumes. And in the case of buttercups, they also are toxic to most livestock.
Cowbrough said he was particularly interested in identifying and studying new species of weeds here and intends to follow up his findings in future years.
Once the plants are documented, an effective control plan can be formulated.
Another difference between the regions is the objective of the harvest. In southern Ontario, for instance, corn is grown to produce mature cobs full of kernels whereas here it is considered a silage crop because of the shorter growing season and cooler temperatures.
Nevertheless, in the early stages, the plants have the same needs and problems.
But the key to effective weed control is understanding their biology and, thus, knowing how and when to hit them for maximum effectiveness. “In order to be able to control a weed, you have to know your enemy,” he stressed.
Cowbrough also stressed the role timing plays in mitigating crop losses due to weed infestation.
While inspecting a corn field owned by dairy farmer Bernie Zimmerman in Chapple, he noticed how the weeds had gained a firm foothold. Due to the lack of heat, the corn crop was not well advanced and so the weeds were well entrenched.
However, the corn had reached the stage where it is important that it be treated as soon as possible because there is a narrow window of opportunity for weed control.
“Corn should be kept weed-free from the two to eight-leaf stage, You can lose as much as a bushel [per] acre [per] day afterwards if it isn’t,” Cowbrough warned.
Zimmerman’s crop is a special variety that is immune to the herbicide Roundup, which often is the weapon of choice for weed control.
But as is so often the case in life, an ounce of prevention can be worth more than a pound of cure. Cowbrough noted the most important factor in preventing weeds is controlling the boundary areas adjacent to fields and pastures.
“By managing the species around the field border means the growers will spend less on herbicides,” he remarked.
But prevention goes well beyond the edges of fields. In fact, it can start far away.
Over the past few decades, the introduction of exotic invasive species has presented a new challenge to farmers. Although exotic species sometimes hitchhike aboard legitimate goods, or even with birds, humans are by far the biggest transporters of unwelcome guests to our fields.
“People are probably the worst culprits when it comes to invasive species,” Cowbrough noted.
And because of that, the government is trying to bring in effective measures to prevent further infestation by human means.
“It’s a national issue,” Cowbrough stressed. “There are both provincial and federal initiatives to try to prevent the spread [of invasive species].”