Cropping Questions and Answers to the Chouteau County Extension Office

I have a prickly lettuce problem in my farm ground. Is it an annual? Prickly lettuce is a biennial and a winter annual.

Do we have herbicide resistance in prickly lettuce in Chouteau County? Tim Siepel, MSU cropland weed specialist has tested prickly lettuce that is 2,4 D resistant. The plants came from the Geraldine area. He has seen glyphosate resistance in the greenhouse. Greenhouse plants are soft plants and will take in herbicides much more readily than a plant growing in the field. In the greenhouse, some lines did require higher rates, so there may be a small amount of resistance. Glyphosate resistance does exist in Australia, and it could happen here.

What herbicide would you recommend for prickly lettuce management? In the field hardened prickly lettuce is hard to kill. Early spring rosettes and early bolting plants can be managed. After bolting no herbicide works, except a serious burndown herbicide. Even after a serious burndown prickly lettuce resprouts if there is any moisture. Huskie seems to work really well on prickly lettuce.

If I think I have resistant prickly lettuce. What can I do to confirm it? Collect some seed and Dr. Siepel can test it over the winter in the greenhouse. Please drop off samples at the Extension office and we will mail the samples to Dr. Siepel.

If we have zero moisture in the soil, how much moisture do we need this fall to produce a healthy winter wheat plant? You will need two inches of rain this fall, which will soak up the top foot of soil. If you can get three leaves in the fall, your winter wheat will have adequate resources to survive the winter.

Can I mix ammonium chloride with urea and apply

it in the fall? According to Clain Jones, MSU Extension Soil Specialist ammonium chloride can be mixed with urea and spread. Waiting until spring is best but the application can also be made in the fall or winter as long as it is applied before a major precipitation event.

How much ammonium chloride would you blend with urea? For fields and crops like durum and Bobcat winter wheat, which are both susceptible to Cl deficiency, Dr. Clain Jones recommends 5 to 7 pounds of ammonium chloride per acre in the blend.

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