NYS IPM Weekly Field Crops Pest Report-Sept. 1, 2023
Soybean Diseases
White mold is very prevalent across the state in soybeans. The conditions have been very conducive for the disease to proliferate. Even growers that applied their fungicides at the correct timing still had infections. There is no complete resistance to white mold in soybeans. Some varieties have tolerance. Sudden death syndrome was found in soybeans in Western NY this last week. Black stem rot was also found in western NY. For more information, please view the following pages:
- White mold or sclerotinia stem rot: https://cals.cornell.edu/field-crops/soybeans/diseases-soybeans/white-mold-or-sclerotinia-stem-rot
- Sudden death syndrome: https://cals.cornell.edu/field-crops/soybeans/diseases-soybeans/sudden-death-syndrome
- Sudden Death Syndrome and Soybean Cyst Nematode: https://blogs.cornell.edu/ccefieldcropnews/2018/09/04/sudden-death-syndrome-and-soybean-cyst-nematode-in-soybeans/
- Brown Stem Rot: https://cals.cornell.edu/field-crops/soybeans/diseases-soybeans/brown-stem-rot
Corn Diseases
There are reports of a few corn disease issues in fields. Gray leaf spot, northern corn leaf blight and northern corn leaf spot has been reported in many areas of the state. There have been a few reports of eyespot. For management information please view the website for the disease of interest:
- Gray Leaf Spot https://cals.cornell.edu/field-crops/corn/diseases-corn/gray-leaf-spot
- Eyespot https://cals.cornell.edu/field-crops/corn/diseases-corn/eyespot
- Northern Corn Leaf Spot https://cals.cornell.edu/field-crops/corn/diseases-corn/northern-corn-leaf-spot
- Northern Corn Leaf Blight https://cals.cornell.edu/field-crops/corn/diseases-corn/northern-corn-leaf-blight
Field Corn Pheromone Trapping Network
The Field Corn Pheromone Trapping Network is coming to an end for this season. We monitored black cutworm, true armyworm, western bean cutworm and fall armyworm. While we will continue to monitor fall armyworm a few more weeks the rest have stopped being monitored. We will be back next season!
For more information view the following webpage: https://cals.cornell.edu/field-crops/corn/insects-corn/western-bean-cutworm
Field Crops Pheromone Trapping Network Interactive Map
Soybean aphid
There have been a few reports of soybean aphids over threshold in soybean fields. The economic threshold for soybean aphids is 250 aphids per plant through the R5 stage of growth. If the plants have reached the R6 there is no economic benefit to spraying the aphids. Soybean aphids have a lot of natural enemies. If the number of aphids is hanging around 250 and there are a lot of natural enemies in the field wait to spray a few days and see of the population declines. If they decline the natural enemies are doing, there job. If not time to spray. To make a sound education decision on spraying for soybean aphids view the publication below.
Should I Spray for Soybean Aphids
https://soybeanresearchinfo.com/wp-content/uploads/2019/03/aphid_visual.pdf
Make sure to check for natural enemies before deciding to spray
This is what 190 aphids look like on just one leaflet.