Nebraska Extension Blog by Jenny Brhel
Wheat Stem Maggot in Corn: Been seeing and hearing of some wheat stem maggot in corn for some fields where corn was planted green into rye. While I see this to a small extent each year, the last time we heard widespread reports was in 2017 (photos and info. at: https://jenreesources.com/2017/06/05/corn-concern-in-wheatrye-cover/). Symptoms include the corn whorls of plants looking wilted. Pulling out the whorl and carefully unfurling it may reveal the light-green maggot. Some key points: the maggot will move from dying rye or wheat into healthy corn. It will not move from plant to plant in corn unless the entire corn plant dies. What we have normally seen is the maggot kills the main stem of the corn plant; however, the plant produces tillers which then produce ears (not typical tiller ears). Because of that, replanting is not recommended. Our Extension Entomologists also don’t recommend spraying an insecticide once the maggots are in the whorls because they won’t have activity against the maggots inside the corn. There are no published thresholds for the maggot once it gets into the corn plant. Here’s an article UNL researchers published on timing and use of insecticides in cover crop/corn systems: https://www.mdpi.com/2075-4450/13/4/348.
Regen Ag Field Tours: A series of Regen Ag tours are available June-August. For now, I’ll share on two of them. On June 11, Doug and Traci Steffen are hosting a compost and covers tour on their farm near Crofton, NE from 1-3 p.m. RSVP at https://practicalfarmers.org/field-days.
On July 8 from 10 a.m. to noon, Junior Pfanstiel is hosting a covers and corn tour on his farm near McLean, NE. Lunch is also included. Junior alternated 4 rows of corn with 4 rows of multi-species cover crops throughout his field with the goal of obtaining the same yield on fewer acres while also having grazing acres. Please RSVP to: (402) 254-6758.
Roundup: Homeowners, please read the active ingredients on jugs before purchasing and using Roundup products. I’ve had several situations where homeowners have bought “Roundup” thinking it was the traditional “glyphosate”, but instead the active ingredient was “triclopyr”. The problem? They work differently. Glyphosate is a non-selective herbicide that doesn’t move in the soil or from plant to plant. It only works on the plant it comes in contact with. Triclopyr is a growth regulator herbicide (same family as 2,4-D and dicamba) that mostly affects shrubs, stump treatment, and broadleaf weeds. It has minimal activity on grasses. It has soil residual activity, on average for 30 days, but can be as much as nearly a year depending on how the microbial life break it down. It can volatilize (move off-target to other broadleaf plants after application) and it can be excreted through the roots of plants that were sprayed to nearby, non-sprayed plants impacting them.
Because of this, some people who have used Roundup containing triclopyr have reported issues with growing vegetables, flowers, their grape vines, raspberries, and around fruit trees. Triclopyr symptoms on plants looks like a “strapping” of leaves where they become bubbly and elongated, but it’s a different look than 2,4-D damage. Plants grown in soil treated with triclopyr may have kinked stems and appear stunted. More info. on triclopyr: https://purduelandscapereport.org/article/the-summer-of-triclopyr-mounting-evidence-for-off-target-damage/. A great resource explaining all the different “Roundup” products on the market: https://www.purdue.edu/fnr/extension/when-roundup-isnt-roundup-purdue-landscape-report/.
