Subscribe
Share
Share
Embed
“Sugarbeet Report” presented by NDSU Extension, features growing tips from NDSU sugar beet specialists and researchers.
This is the Sugarbeet Report, bringing you the latest information from NDSU throughout the sugar beet growing season. The sugar beet battle with the root maggot is chugging right along. Mark Boetel, NDSU Extension entomologist, is here to tell us what the root maggot is up to. Mark, our weather started out cool and mild, then it got hot. How did that impact the root maggot?
Mark Boetel:About two weeks ago, we were actually running behind. We're about five day calendar days behind the historical average for peaks in fly activity. We subsequently had that hot streak where we had between three and five days in the nineties followed by several days in the eighties. And so that's really accelerated root maggot development. And now we're not only caught up, we're actually looking at peaks occurring between three and five days ahead of average for the area.
Bruce Sundeen:Recently, we've had stormy weather. How does that impact root maggots?
Mark Boetel:Yeah. Earlier this week, that likely has impacted fly counts on the sticky stakes. So in some of those fields that were affected, we may actually see some what I would call false lows in activity where the flies are actually out there hunkered down, but they're not entering the fields and being captured on the traps. Something else with heavy rainfall events, a few isolated areas of that too, and that can actually kill adult flies. So that can impact counts at the time, but also even survival. And then certainly that would put a damper on the larval infestations that are produced from that activity or that lack thereof.
Bruce Sundeen:Mark, where are some of the problem areas?
Mark Boetel:In North Dakota, we've seen very high activity at Auburn, Buxton, Crystal, Grafton, the Grand Forks, Merrifield area, Oakwood, Park River, Reynolds, Saint Thomas, and Vestleyville. And then on the Minnesota side of the river, Ada, Angus, Borup, and Crookston are where we're seeing the most activity.
Bruce Sundeen:What's the root maggot doing right now?
Mark Boetel:We're still seeing heavy emergence. Despite even having some early flare ups, we're still gonna have a lot more flies likely to come. So right now, mating and egg laying are still occurring and they're entering fields as well. And those eggs from the earlier emerged females are starting to hatch, so they're gonna be going after plants very soon. Fields treated at planting time with a high rate of a granular insecticide followed by a well timed post emergence should do very well. However, plants that begin wilting and dying and that may be in fields where we might have missed some of those rains are not gonna be sufficiently protected. We need to watch out for that. If the weather returns to being hot and stressful that way, that's gonna accentuate the effects of the larval feeding on the roots. The recent rains will certainly help activate those at plant and post emergent supplied granules, and some of those granules have already been applied starting earlier this week. But growers that choose to use a liquid should be spraying when they surpass the conservative threshold of 70 flies that's in their immediate area. If they do have that plant protection on though, they can probably push that a little higher and wait to make those applications, two to three days before anticipated peak fly for their area.
Bruce Sundeen:Mark, do you have anything else to add?
Mark Boetel:Just one more thing, and that would be that we have a root maggot plot tour coming up at Saint Thomas, North Dakota. We are in a new location very close to where we have been for several years, but we'll put information up on that very soon. But we're, looking at shortly after the July 4 or maybe the following week. We have a lot to show people on, using either new approaches to using old conventional tools, and then we also have some experimental sand new insecticides to showcase as well.
Bruce Sundeen:Thanks, Mark. Our guest has been Mark Boetel, NDSU Extension Entomologist. This is the Sugarbeet Report, bringing you the latest information from NDSU throughout the sugar beet growing season.