|
|
AgAlerts 2003 From Griggs County
|
Issue # 6, June 20, 2003
There has been several questions concerning large patches of yellow flowering weeds around sloughs over the past few years. These weed is Swamp Ragwort. This is an annual or biennial weed. For more botanical information, click on the following link, Swamp Ragwort.
(click on picture to enlarge)
There has been scattered reports of potato leafhoppers in Traill county this past week. Potato leafhoppers damage is referred to as hopper-burn. Leaves become dwarfed, crinkled, and curled. Small triangular brown areas appear at the tips of the leaves. Potato leafhoppers are very active and jump or fly when disturbed. Both nymphs and adults can be found on plants, usually on the underside of the leaves. Both adults and nymphs will run backwards and sideways very rapidly. Nymphs are wingless. Control thresholds are an average of one leafhopper nymph per trifoliate leaf. The following link will give you more information on potato leafhoppers.
Small grains are progressing fast and be sure to assess the crop for the proper stage for fungicide treatments. Fusarium graminearum (scab) spores are now being detected in spore traps in the Fargo area. Barley treatments for leaf and head diseases is at early full head emergence. If Fusarium head blight is the target disease, treat when the heads are out of the boot. Wheat treatments are at early anthesis (flowering). Apply at 10-25% of the main stem spikes have started to flower. The Small Grains Disease Forecasting Model can give local information on current disease status for your local area.
Reports are increasing of aphid infestations in small grains in the south and eastern counties. The bird cherry-oat aphid has been the dominate aphid found. This aphid is very dark green, almost black in appearance with a reddish band at the back. The optimum results from applying an insecticide for aphid control in small grains occur when treatments are made at flag leaf to boot. Through a yield response is associated with treatments at the fully headed stage, it is much lower, and often only equals the cost of the treatment. If the control of scab and aphid with one application is the goal, treat at the optimum stage for scab instead of the aphids. The loss of yield and quality are much great with scab than with aphids may have. For more information on aphid management go to the following link, Aphid Management in Small Grains, Corn and Sorghum E-493.
Please Contact Our Office For Additional Information
E-mail: john.swenson@ndsu.edu
Go to the 2003 AgAlert Index Page