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“Sugarbeet Report” presented by NDSU Extension, features growing tips from NDSU sugar beet specialists and researchers.
This is the Sugar Beet Report, bringing you the latest information from NDSU throughout the Sugar Beet growing season. Sugar beet growers have a tiny adversary in the form of the sugar beet root maggot. This year, the root maggot's development is slower than usual. Mark Botel, NDSU Extension Entomologist, has the latest. Mark, growers planted early this year, but things have cooled and there's been plenty of moisture. How has this impacted the root maggot?
Mark Boetel:Really, the rain may actually help us in a couple of ways. We'd all like it to kinda normalize and dry off a little bit. It can help us with activating those planting time insecticides, both those that were applied to the soil as well as the seed treatment insecticides and then the rain will also help soak in and activate post granules if they've been applied. And another positive would be that some flies, as they're trying to emerge from the soil as adults, may actually be killed from those saturated soils.
Bruce Sundeen:Where are the early hotspots this year?
Mark Boetel:Well, right now, and it's fairly early to tell, but right now, the sites that are showing the most activity include Reynolds, Buxton, Crystal, the Ardoch, Vestleyville area, Cashel, Crookston, Climax, Cavalier and then the Grand Forks East Grand area.
Bruce Sundeen:Mark, what's your root maggot model forecasting when it comes to peak fly?
Mark Boetel:Initially, we were off to an early start with maggot growing degree days, but the cool weather in the last couple of weeks associated with those rain systems has really slowed development of the overwintered larvae. They're back on track with growing degree days to where we're probably expecting peaks to occur at about normal timing next week. The extended forecast is suggesting drier, more stable weather patterns in the next several days, so we should see a huge increase in root maggot fly activity over this coming weekend and into next week. That will be associated with movement in the beets, from last year's beet fields along with mating and egg laying taking place at that time. Stable weather does prevail. Most sites should peak between June 9th 14th as it always occurs, the more southern latitudes peaking first.
Bruce Sundeen:What about control options?
Mark Boetel:Post emergence granules should be applied as soon as possible. They work best if they're at least applied at least 5 days ahead of peak fly. Post emergence liquid insecticides should be applied about 2 to 3 days before peak and those treated fields should be monitored for flare ups for another week or so. Fields treated at planting with a high rate of a granular insecticide followed by a well timed post emergence application should be fine. However, by late June, plants and fields that were not sufficiently protected will begin wilting and drying. Hot dry weather, if we receive some of that, we'll accentuate those effects on the plants.
Bruce Sundeen:Is there anything else going on with insects in the region?
Mark Boetel:Couple of weeks ago, we had some outbreaks of aster leafhopper in several beet fields, within the region. Those adults actually did not overwinter in our area. They came in, they were blown in on upper level air currents from southern states and they'll likely produce subsequent generations. Fields where those observations were made a couple of weeks ago should be monitored in the next coming week or so for those progeny to determine whether control measures should be undertaken.
Bruce Sundeen:Thanks, Mark. Our guest has been Mark Botel, NDSU Extension Entomologist. This is the Sugar Beet Report, bringing you the latest information from NDSU throughout the Sugar Beet growing season.