U of S fights back against grasshoppers
By Colleen MacPherson
They're back, and as hungry as ever, but thanks to some early planning and about $45,000 invested in various methods of control, grasshoppers are not expected to cause nearly the damage they did last year in the University's research fields.
"Last summer, we basically had to walk away from a whole season's work because the crops were too damaged to do anything with," said Rick Holm, Director of the Crop Development Centre. "Now, I think we've protected the crops to the point where they'll withstand the final onslaught."
Early in the growing season, eco-bait (wheat bran treated with insecticide) was spread around the perimeters of the research farms to try to keep the grasshoppers from moving onto the land. Some borders were sprayed with insecticide when the pest populations were seen to rise, and spot treatment was also used, Holm said.
Finally, the University resorted to aerial spraying, treating about 2,000 acres at the Kernen, Sutherland and Goodale farms as well as what is called the pulse lands near the Goodale Farm at Floral. Two insecticides were used with what Holm termed "reasonable results", but because the grasshopper hatch occurred over a prolonged period this year, control has been challenging.
On a recent tour of the Kernen Crop Research Farm just east of the city, Holm pointed out that the various species of grasshoppers there have now taken flight, greatly reducing the effectiveness of further control measures.
Given the smorgasbord available in University fields, the voracious insects show a preference for cereals, with wheat and barley being more popular than oats. "They have to be fairly hungry before they'll move into canola, and they will go into peas and lentils but in lentils, they just nip the flowers off so the plant looks fine but there's no seed production."
Grasshoppers aside, it has still been a difficult year for field trials, mainly because moisture levels are "very marginal". Holm said the farms received about 50 per cent of normal precipitation in May, 33 per cent of normal in June and nothing at all since the first weekend in July - what he termed the "soaker weekend" when upwards of two inches of rain fell.
"The result is that plants are maturing abnormally fast because they've run out of water again, but the data we collect this year will be much more useful and reliable than last year."