Ag Partners Agronomic Insights
 Adam SteffelLe Sueur |
 Hannah HernkeGoodhue |
 Brett DeckerLewiston |
 Brady CoulsonEllsworth |
WEST
During a spring of trying to get everything done in-between our weekly rains, guys are finally starting to wrap up the planting. Not only has the weather made planting difficult but it has also made spraying pre-emerge herbicides on the crops a difficult task too. There are several fields out there that originally had a plan to get pre-emerge sprayed on but with the rains it never got done. These fields are starting to look pretty weedy already and it will be important to be out scouting. Most of the earlier planted fields are going to need to be sprayed their post-emerge shot as soon as we dry up from our current shot of rains. Also, while scouting for weeds keep an eye on the crops themselves. They are starting to show some nutrient deficiencies and mixing some micro’s in with your herbicide could be the most efficient way to correct some of these issues. – Adam
Pictured below is an example of Zinc deficiency in corn.
Through the eastern geography almost everything is planted. We are on to spraying pre-emerge and early post emerge herbicides on both corn and beans. Last week, we worked through calls on poor emergence due to crusting in fields planted from April 23rd-25th. Rotary hoe was warranted in places and replants in even fewer places.
Now that we’ve gotten corn and beans in the ground, we shift our focus to 1st cut alfalfa. Many may be noticing alfalfa weevils are out and feasting. The last few years of mild winters and decreased rainfall have allowed these weevils to threaten our hay crop around 1st and 2nd cutting.
Weevil larvae skeletonize alfalfa leaves and target new growth of the plant. In uncontrolled environments, alfalfa weevil larvae will work quickly to defoliate alfalfa plants. This defoliation can reduce forage stand, quality, and yield.
Pictured below on the left is an example of alfalfa with moderate defoliation. Weevils are identified by a black head and white stripe down the back.
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Weevil Management: If there is weevil pressure and alfalfa has not been cut, plan to cut when possible. Monitor regrowth, look closely at windrows, sweep hay, and look for feeding on regrowth. If significant defoliation is occurring or thresholds reach above 2 or more larvae per stem, spray immediately.
Potato leafhoppers and pea aphids can still be significant, but weevils will have the most impact on our alfalfa crop at this time of the year. Contact your agronomist if you have concerns and we will make up the best crop protection recipe for the insects we might be encountering in the hay! – Hannah
As corn and soybean planting wraps up in southeast Minnesota, the next season is upon us, forage harvesting. What looked like an early season for the alfalfa has been hampered by some cool, wet conditions. With the cool and wet conditions, it brought some growing challenges and a disease pressure we have not seen here in southern Minnesota. Spring black stem spot is caused by the fungus Phoma medicaginis that can be a devasting disease. It will limit growth of the plant causing decreased yield, quality, and can reduce stand survival. The first appearance is the yellowing of lower leaves with small, dark lesions. Once the disease is in the plant you will see the upper leaves stunted, deformed, and starting to wither. The fungus is the result of re-growth left from the fall that survives on decomposing foliage. Then, with the rain and cool spring it splashes up on new growth and becomes infected. Now because of this I would still highly recommend leaving the growth this coming fall as we still need to protect the alfalfa from any winter injuries that could occur.
Where we were severely affected, we sprayed Priaxor 2 weeks ago to protect the plants from going backwards. Also, by doing this we will protect the second crop from being affected early in its recovery.
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Pictures on are from the same spot in the same field. Pictures on left are prior to spraying and pictures on right are 10 days after the application of Priaxor.
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As some growers decided not to spray, they have harvested their first crop already. Those growers were surprised by the lack of quantity and moisture of their forages, however more importantly they noticed large, blackened areas in the fields where the disease was much worse. You can see in the picture below, those blackened areas.
To mitigate the severity on fields that were not sprayed it is recommended to spray a fungicide on these as soon as we get some re-growth to help the alfalfa and gain some quantity for the next cutting. If you have any questions or concerns make sure to reach out to your Ag Partners agronomist. – Brett
Planting in Wisconsin is pretty well wrapped up and spray season is now in full swing. As we shift gears, it is important to remember that seed return season is upon us. Please be timely with your seed and packaging returns, as seed corn return deadlines are June 15th, with packaging soon after. Contact your agronomist if there are still some returns on farm. Thank you!
– Brady
