Agriculture chemicals poised to rescue canola crops

A surprise infestation by a southern U.S. pest is threatening to whipsaw canola crop growth in the Peace region unless farmers can thwart it with chemical intervention.
The earliest reports of the Diamondback moth infestation began to appear in the days leading up to the end of June. By July 2, reports of the infestation were coming from virtually every Agricore outlet throughout the Peace. It’s been confirmed that the pest, which rode into the region on strong winds from the southern states, will complete its second lifecycle by this weekend.
“I never thought I’d ever see this in my career,” said Richard Lussier, the Agricore agronomist for the Municipal District of Smoky River No. 130. “It’s the first time we’ve ever seen them up here. Typically, it’s a pest that ends up in Southern Alberta.”
“We should’ve put a tariff on the pest at the border,” he joked.
Diamondback moths don’t hurt crops directly, but lay the eggs that develop into moths over a 20-to-30 day life cycle. During that cycle, moth larvae will munch on canola, mustard, broccoli, cabbage and several other greenhouse plants.
In years when conditions are right for the moths – that is, when moths arrive in large numbers in early May when temperatures are hot – diamondback infestations can cause millions of dollars in damage. If they are enough of them, they can strip all the leaves on the entire plant. They will also eat buds, flowers, seed pods, the green outer layer of plant stems and even developing seeds.
More important, however, is the question of how such swift infestations can be controlled. Organic foods have never been more popular, but it appears the recent outbreak underscores the role agricultural chemicals still have in our health-conscious society.
Agronomist Lussier said biological and weather factors do help control pest populations – but only when conditions are right. Unlike chemicals however, these factors are difficult to utilize in a precise or timely manner. Science confirms that in some cases at least, natural predators or adverse weather conditions often aren’t strong enough to control pests or weeds for a prolonged period of time.
Lussier cites the example of the Bertha army worm. It’s an agricultural pest whose population can spike severely to rise above and stay ahead of its predators for up to two years. For that duration, Lussier said, the worms are free to destroy everything in its path until pathogens and predators eventually overcome them.
In reference to the time efficiency of pesticide chemicals versus biological controls, Lussier is hesitant to choose sides.
“I guess pesticides can be effective. I don’t want to wade into the debate on that, but I feel that Agricore is fairly responsible because we use economic threshold figures to determine the necessity for chemical applications.”
Lussier acknowledges that the dark side to chemical control is the havoc it wreaks on friendly populations but from an economic standpoint, he said agriculture has to weigh the consequences of intervention. If nothing else, he said, a decision to spray based on economic thresholds and population overbalances will result in protecting the food supply in a global context.
Agricore employee Chris Maissonneuve sells crop inputs during the day, but helps his family with some of the farm chores after work. He said it’s difficult to generalize the extent of the moth’s damage as it varies from field to field, but added it’s very likely the damage could intensify to a higher and more widespread level. Although moth larvae are the culprits which may or may not be more vulnerable during growth stages, he said the only strategic edge farmers have over the critters is to spray.
“I suspect we’ll be well into crop dusting by the week of July 18.”

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