ISSUE 7   June 26, 2008

PEST CONTROL IN VEGETABLE CROPS

A couple of weeks ago I mentioned a web site to find pest control information in vegetable crops. There another good web site with additional information. It contains the North Central Regional (NCR) "Midwest Vegetable Production for Commercial Growers". It is available through Purdue University.

http://www.btny.purdue.edu/Pubs/ID/ID-56/

 

LEGALITY OF MIXING PESTICIDES

1. Follow label directions.

2. Do your own jar formulation compatibility test.

3. Apply products at your own risk.

4. Call the representatives of the products for advice.

These are the four main recommendations for those thinking about combining pesticides that are not labeled for tankmixing and one-pass application.

Some research has been done with tankmixing herbicides to cover a normal weed spectrum but not much research has been done on tankmixing two types of pesticides. The main source of information on this topic would come from the manufacturers. What works? What doesn’t work? Could injury happen and how much might occur? These are questions that should be considered.

Products registered on the crop can be legally tankmixed together unless restricted by either pesticide label. If not restricted then - you do so at your own risk, and the chemical companies do NOT have any liability if one or both products do not work, or if crop is injured. If you are intending to tankmix two products that are registered for separate use only, do a jar test first to confirm formulation compatibility. Jar test information is described on most pesticide labels.

Just because products are registered or the tankmix is registered doesn’t mean that a one-pass application will be effective. Generally, the tankmix is being applied at the optimum time for one of them (herbicide) and may not be the optimum timing for the other (fungicide). Controlling weeds at the 2-, 3-, or 4-leaf crop stage may be too early for effective for disease control (depending on the type of weather).

 

WEED CONTROL IN WHEEL TRACKS

There is ample evidence of increased weed pressure in wheel tracts of crop planting equipment. Soil compaction by tires creates greater seed to soil contact, and with adequate soil moisture makes ideal conditions for germination. PRE herbicides that are have not received sufficient moisture for activation may not control these bands of weed. Even PRE that have been activated may show less control in these areas.

Weeds in wheel tracks have also been seen after POST herbicide applications (glyphosate) made during dry conditions. Dust is the main culprit and can significantly reduce weed control on the wheel track region. Many have fabricated special application equipment to apply a greater amount of herbicide in the wheel track area or apply before or after the equipment passes the weeds. There are not good solutions to overcome dust inactivation of herbicides.

 

CADET HERBICIDE

Cadet is a new postemergence broadleaf herbicide for use in corn and soybeans from FMC. It contains the active ingredient fluthiacet-methyl, which is a PPO-inhibiting herbicide (Group 14). Cadet can be used on field corn, seed corn, sweet corn and popcorn from V2 until 48 inches tall or before tasseling, whichever occurs first. The preharvest interval in sweet corn is 40 days. In soybeans, it can be used from first trifoliate to full flowering. Cadet rates are 0.4 fl oz/a in tank mixtures with glyphosate, 0.5 fl oz/a with other broadleaf herbicides, and 0.6 or 0.9 fl oz/a if applied alone. Cadet has excellent activity on velvetleaf and controls plants up to 36 inches tall at 0.6 fl oz/a or at lower rates in tank mixtures. Cadet has similar velvetleaf activity to Aim and Resource. At the 0.9 fl oz/a rate, it is labeled to control 2-inch tall lambsquarters, waterhemp, and jimsonweed and 4-inch tall pigweed, but these weeds are only listed as suppressed at lower rates. Cadet needs surfactant or crop oil plus a nitrogen additive if applied alone, but tank mixtures with a fully loaded glyphosate formulation should only need the ammonium sulfate that is typically used with glyphosate. Cadet has contact activity (does not translocate) and basically has no residual activity. It is an option when targeting velvetleaf alone or in tank mixtures with other broadleaf herbicides.

 

VOLUNTEER CORN CONTROL IN SMALL GRAINS

I have received several phone calls on volunteer corn control in small grains. Below is a list of postemergence grass herbicides labeled for use in small grains and their control of volunteer corn.

Herbicide

Vol corn control

Axial XL

None

Achieve

Not known

Discover

Excellent

Puma

Excellent

Everest

Excellent

Maverick

Not known

Olympus

Not known

Rimfire

Fair to Good

Silverado

Fair to Good

Rich Zollinger
Extension Weed Specialist
r.zollinger@ndsu.edu


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