Bruce Sundeen 0:00
This is the sugarbeet report, bringing you the latest information from NDSU throughout the sugarbeet growing season. Lately, the weather has been good for growing sugar beets, but what else is growing out there? Mark Boetel NDSU Extension Entomologist has the latest information concerning the sugarbeet maggot Mark last year growers faced a 15 year high sugarbeet maggot population is there any chance are cold weather reduce some of the numbers,
Mark Boetel 0:28
We do really have a pretty significant maggot problem on our hands. And then as far as the cold winter goes, unfortunately, they're very cold tolerant. So the winter likely had zero effect on their survival. So we've got on our hands what we dealt with in 21. So the previous years surveys on flat counts can tell us a lot not only the severity, the potential but also the locales of where those populations could be. So that gives us an idea where we can kind of zero in and know where we're gonna have problems this year.
Bruce Sundeen 1:01
The weather has really turned around and warmed up the last couple of weeks how's it affecting the maggot
Mark Boetel 1:07
getting things going with plants, not only plants, but also insects as sugarbeet root maggot degree de units are still averaging we're probably somewhere around a week behind the historical averages. Although the maggots are behind average or normal, if you want to call it that the plants are also quite behind. In many fields, there are a lot of leak planted fields. So that's going to be a concern. Unfortunately, the plants are even farther behind average than the root maggot, those tiny plants in those late planted fields are going to be very susceptible to attack from insect injury.
Bruce Sundeen 1:42
As usual, I know it's early Mark, but can you give us a rough idea when peak fly might occur?
Mark Boetel 1:47
Sure, and it is somewhat of an early forecast here yet. So I want to give that a little bit of a grain of salt. But in the southern Valley, we're looking at somewhere between the 15th and 17th for peak fly in the the Central Valley moving up between Hillsborough Ada, Grand Forks area may be part of that area, the 17th to the 19th of June, and then the northern Valley, including some areas around Grand Forks and then all the way north to Canadian border, somewhere between the 21st and 23rd of June. We'll know a whole lot more next week as we accumulate more degree day units so we can zero in on a much closer forecast at that point.
Bruce Sundeen 2:29
Where are the maggots showing up so far?
Mark Boetel 2:32
Yeah, the early hotspots we're seeing right now includes Auburn Cashel crystal Drayton up way up north, and we're seeing some in the Cavalier area as well. Moving down south in the East Grand Forks and Reynolds area, as well as some additional areas of North include St. Thomas, of course, the perennial hotspot, and then oak wood as well. But that list is short right now. And it's definitely going to grow as time goes in the next couple of weeks.
Bruce Sundeen 3:01
Okay, Mark. Now for the million dollar question. What can growers do to manage the root maggot problems,
Mark Boetel 3:07
Growers in high risk areas should plan just expect that they're going to need to put on a post emergence insecticide given this year how late a lot of fields are planted, that's just really should be an assumption. Post granules should be applied as soon as we're able to. There are some limitations there. Because plants are so tiny, we have to consider insecticide load on those little plants as well as running an implement like a rotary hoe through the field, you don't want to tear them up too much or cover up the plants. So once we get to about the Four Leaf states, they should be ready to treat and granules work well as long as you get a rainfall afterward, anywhere and the application can be made anywhere between one and two weeks ahead of peak fly. And even shortly a couple of days before peak if necessary. post emergence liquid liquid insecticides on the other hand need to be sprayed much closer to peak fly we want to have a lot of fly activity in the field. So we get good mortality. So somewhere between two and four days ahead of peak fly, and then follow up survey the field and Repeat if necessary a couple of days after peak fly.
Bruce Sundeen 4:16
Thanks Mark. Our guest this week has been Mark Boetel NDSU extension entomologist. This is the sugarbeet report, bringing you the latest information from NDSU throughout the sugarbeet growing season
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