Crop & Pest Report
Dr. Tom Gulya, USDA-ARS, is conducting a survey to monitor the downy mildew pathogen for race changes and fungicide sensitivity.
Downy mildew is caused by a soil borne pathogen that can survive for many years in the soil. When frequent rains occur after planting, the pathogen produces swimming spores (zoospores) that infect roots and cause a systemic infection.
As canola enters bloom, the crop becomes susceptible to white mold. Fungicides are available that can help manage the disease, but the more important decision is whether or not the environment is favorable for infection and disease development.
Risk of tan spot continues in some NDAWN locations in the northern tier of counties. However, the risk of FHB has diminished, due to warmer temperatures and dry conditions occurring now and predicted for the next few days.
This article is a rework of an article I wrote a couple of years ago. I also addressed this topic briefly earlier this season. Nevertheless, with the extensive flooding/ponding this past week, I have decided to provide this information again.
Excessive rainfall and regional local flooding has resulted in many fields that have not been planted with the intended crop.
Agricultural production is in full swing in North Dakota, and flowering field crops or weeds in the field are important food sources of many species of pollinators, including honey bees and native bees.
Soil samples collected by the NDSU Extension Ag Agents in North Dakota indicated low levels of overwintering wheat midge larvae (cocoons) for the 2013 season. With the majority of soil samples statewide being low risk for wheat midge infestation, minimal insecticides should be needed for controlling wheat midge in most of the state in 2013.
Our IPM Scouts are picking up low numbers of soybean aphids (< 80 aphids per plant) in Cass and Richland Counties. Soybean aphids are typically concentrated in the upper trifoliates until flowering.
Barley thrips have been found in Ward, Cass, and Linton Counties and central ND near Rugby. Some fields have high numbers of barley thrips (>5 thrips per stem) while other fields are still low in numbers (0-3 thrips per stem).
Maps detailing corn accumulated daily growing days, percent normal rainfall, departure from normal average air temperature, and accumulated wheat growing degree days.
With many fields too wet to plant to desired crops many are turning to short season grass crops to plant, like millet, sorghum, and sudangrass.
Page 22 and 23 of the North Dakota Weed Control Guide gives a summarized version of many different weed control programs in Roundup Ready corn.
Monsanto recently submitted supplemental labeling to the ND Department of Agriculture that would allow aerial application of Warrant Herbicide to the crops found on the full product label.
The ND DOA has issued a special local needs (SLN) registration to Bayer CropScience, allowing aerial application of Laudis® herbicide to control weeds, including kochia, in cornfields.
The Crop and Pest Report has been used to alert growers of new pesticide registrations. Some registration submissions may originate from the manufacturer, as in the case of supplemental labeling, or sometimes the North Dakota Department of Agriculture may issue a special state label (special local needs (SLN) label (example, see Laudis information below).
Soybean in the state always looks green as it emerges. Iron in soybean is mobile in the plant until the first trifoliate leaf emerges. At that time, for some mysterious reason iron becomes immobile in the plant and has to be taken up fresh for each increment of added tissue.
As I am writing this at 3 AM making sure my sump pump doesn’t die, it is clear that scattered showers means something different than it did years ago.
Ninety-seven percent of scientists agree that man-made global warming is real, and the 3 percent of scientists that do not think global warming is influenced by human activities are far below their colleagues in their expertise. This is a paraphrase from a paper written in 2010 by Anderegg, et al. in the Proceedings of the National Academy of Sciences of the United States of America.
With substantial rains last Thursday through the weekend across much of the state, many NDAWN locations are showing risk of tan spot again.