Bt Corn Technology Insect Control Benefits

Corn Earworm Benefits May Reach Across To Soybeans And Cotton

DYERSBURG, TENN.

   University of Tennessee, IPM specialist, Dr. Scott Stewart spoke with growers at the Tennessee Grain and Soybean Producers Conference about the new corn Bt technologies coming into the market.

   Stewart discussed the advantages of VT Triple Pro and SmartStax which are being marketed by Monsanto. Stewart said, “we are getting a lot better control of ear feeding caterpillars. The new traits also allow us to reduce the size of our non-Bt refuge; a significant issue for some folks.”

   Stewart explained the new Bt traits have worked well. “We are getting excellent control with these new technologies on corn earworms, whether it is VT Triple Pro, SmartStax or Viptera. We are also getting excellent fall armyworm control in the ear.” Viptera, a Syngenta technology, is not currently registered for use in 2010.

   Stewart has not seen a yield bump. “It has been a little surprising to me that we have not been getting a yield bump considering most of our tests have been late planted and had well above average pest pressure. That doesn’t mean there are not any potential benefits. One of the things that have come out is that we are seeing some improvements in grain quality. There are examples where the new Bt traits have reduced levels of mycotoxins, such as aflatoxin.”

   Stewart works across multiple crops and sees Bt corn technologies benefiting soybeans and cotton. Stewart explained, “Corn is a huge host for corn earworm, a very high percentage of the corn earworm population goes through corn. Because these new Bt traits are much better at killing corn earworm, I expect they will significantly reduce populations found in late soybeans, cotton and hopefully some other crops.”

   Stewart makes this observation about the new wave of Bt corn technologies, “the reality is that in three or four years, these new trait packages will likely replace those currently on the market. You are either going to be growing non-Bt corn or you are going to be growing the new stuff. The technologies we have been using like Yieldgard corn borer and Heculex I are going to disappear from the market just like Bollgard did in cotton.”

   Stewart added, “in some areas where non-Bt corn is grown, we are seeing some significant increases in yield by better managing insect pests, particularly the southwestern corn borer. With some scouting and treating as necessary we have been able to increase yields 15, 20 or 30 bushels in some cases with just one insecticide application. There are opportunities out there in the white corn market where much of the corn is GMO free because of consumer demand.” Δ

REGINA LAROSE: Associate Editor, MidAmerica Farmer Grower

Dr. Scott Stewart, University of Tennessee, IPM specialist, discusses the new corn Bt technologies coming into the market.

Photo by John LaRose, Jr.