What's Bugging You?

Details: Created: Monday, 02 August 2021 11:59; Written by Mark Warmka

Peoples Producer Page

What’s Bugging You?.........In-season crop scouting is an important task this time of the year. The hot, dry weather does lead into more risk for particular insect pressures. This weather can favor spider-mites in soybeans. They have been found in some areas of Minnesota and Iowa. They are very, very small and tough to see. You can see leaf reaction in some cases, with lower leaf yellowing or loss. You can tap leaves over a white sheet of paper to detect mites. They will show up as tiny dark specs that can move on the paper. Scout from edge of the field toward the middle of the field to determine infestations and thresholds.

Grasshoppers can be a problem in a dry year as well. They are voracious feeders that leave obvious signs. Again they are more prevalent on field edges and grassy areas. Large populations can cause yield loss quickly.

Soybean Gall Midge is a relatively new pest that has been moving in from the west. Recently the U of MN extension service has identified this pest in nearby Watonwan County (St. James, Madelia area). So we will need to be on the lookout for this one in the near future.

Nematodes don’t necessarily build because of hot weather but nematode pressure can express more dramatically when plant roots are already stressed by lack of sub-soil moisture. You need to be aware of this sneaky yield robber and manage it. Yellow beans aren’t always Iron-Chlorosis, sometimes it is nematode injury. Soil test to determine populations. Also be aware of different nematode control traits in seed varieties, and the need to vary that method of control to fight back against pest resistance.

Soybean Aphids typically do not like the hot weather, so thus far in Minnesota we have not seen very much aphid pressure. But don’t go to sleep on these just yet. If we get more temperate weather, they can build populations very quickly. Pay attention to economic thresholds for treatment. Keep scouting!!

Its been a year with an increase in corn rootworm feeding. Be sure to evaluate standability of your corn stalks leading up to harvest. Work with an agronomist to identify the rootworm (western or northern) so you can make a plan for control in the future. You may want to grab the spade and dig up a few plants and examine the roots to see if any significant feeding has occurred. You need to pay attention to different Bt traits in your seed choices and/or insecticide choices to manage for resistance reduction. There are no rescue treatments for the current crop, rather this a management process for solving this problem next year.

Please enjoy the rest of the summer…….be safe and take care of yourself and your health……we want you around for many crop seasons to come.

Take care,

Mark