Most corn is between the V6 and V12 growth stages. Growers, seed companies, and agronomists are monitoring northern corn leaf blight in the area as lesions are now visible. Scouting will be important especially on more susceptible hybrids following corn. Corn blotch leaf miners are now active, but at low levels. Overall, the corn crop condition has been improving with a slightly drier second half of June and producers have been actively fertigating.
Lesion from northern corn leaf blight on V7 corn plant
Most soybeans range from VE to R1 (beginning bloom). Insect pressure is low and has mainly been green cloverworm, which appears to be decreasing. In some fields they caused up to 10% defoliation, which would still not be economical. We’re starting to see some Septoria brown spot on lower leaves of soybeans. Marestail has been more problematic this year due to later emergence, herbicide resistance, and late pre-plant herbicide applications due to the wet weather. Second cutting of alfalfa is starting and the few wheat fields in the area were hit hard by stripe rust, Fusarium head blight, and wheat stem maggot.
Defoliation from green cloverworms and thistle caterpillars.
Agronomic concerns for the coming week:
- Watch soybean growth stage limits, pre-harvest interval, and crop rotation restriction times on herbicides.
- Look up northern corn leaf blight ratings for all of your hybrids, scout hybrids w/weak ratings first.
- Evaluate herbicide program for next year based on current marestail pressure in your fields
