Crop & Pest Report
Weather Forecast: July 30 – August 5
Maps detailing corn accumulated daily growing days, percent normal rainfall, departure from normal average air temperature, and accumulated wheat growing degree days.
Information from the Southwest region of North Dakota
Information from the South Central region of North Dakota.
Information from the Northeast region of North Dakota.
Beginning in late winter and early spring I was contacted by many folks in the region about media adds of adjuvants that contain nano-materials.
Question: I have an interesting question for you. Word around the local coffee table, is that using a 40% Deet insect repellent kills weeds… A producer is “experimenting” with it in his lawn and he showed me that it does work. It killed the dandelions, lambsquarters, common mallow, etc. The grass surrounding the weeds looks like it was killed too. However, my question is, will anything grow back at all after it has been sprayed with a 40% Deet?! Is it the Deet that’s killing the plant? Any thoughts, comments?
In the last issue of the NDSU Crop and Pest Report (#12) I included information on Palmer amaranth. In the article I indicated the following: Below are reasons why it is being called “Satan” and why growers should quickly destroy any plants found. #7. Female plants can grow to more than 10 feet tall with a 5-6 inch stem girth and seed heads more than 1 foot in length. Male plants are small and generally non-competitive.
Harvesting of wheat and other small grains is starting to begin across the state, whereas some of the wheat has a few more weeks before full maturity.
We have received dozens of calls about soybean downy mildew in the last week. This is a disease that is often seen in soybeans, but generally occurs at very low levels and rarely causes economic yield loss.
Dr. Kiersten Wise at Purdue University wrote an excellent article to help growers distinguish Septoria brown spot and Bacterial blight in soybeans in the July 16th issue of Purdue’s Pest and Crop Newsletter.
Low levels of dry bean rust has been showing up in the state. This is not necessarily surprising, the frequent and heavy dews and moderate to warm temperatures have been favorable for rust development.
As sunflowers begin to bloom it is important to scout for sunflower rust.
The recent warmer weather has been nearly ideal for corn development. Based on NDAWN maps, corn growing degree (GDDs) accumulations are running slightly ahead of the long term average for most of the state, with the some locations in the southeastern part of the state running 50 to 100 GDDs behind normal.
During the warm and drier part of the summer it is easy to forget the challenges of planting the 2015 crop. Many fields had issues with excess water during this and pervious growing seasons.
I’ve updated this article on timing of insecticide application for management of sunflower head insects from an old issue of the 2013 Crop & Pest Report.
Red sunflower seed weevil (RSSW) adults are emerging now and will fly to the nearest flowering sunflowers.
Pheromone traps run by the IPM Survey scouts showed high numbers of banded sunflower moths located in southwest and central North Dakota and increasing numbers of sunflower moths in north central and northeast North Dakota (see maps).
Eighty-eight fields were scouted by the IPM Scouts for soybean aphids last week. The IPM scouts in North Dakota and Minnesota found soybean aphids in 60% of the soybean fields surveyed.
This week’s Good Bug Corner featured insects are the Monarch butterfly in the insect family Nymphalidae.