By Clint Thompson
Cotton growers have their reservations about the yield potential of nematode-resistant varieties. But they should also remember those varieties are best utilized in fields with an active nematode problem.
The Georgia Cotton Commission and University of Georgia (UGA) Extension plant pathologist Bob Kemerait remind growers to consider that important fact when debating the use of resistant varieties as a management option for nematodes.
“A lot of times growers will ask, ‘How are they going to yield?’ Yield is everything to the growers. I would say as our varieties improve, and definitely in the past, nematode-resistant varieties may not have yielded as high or as well as susceptible varieties outside of a nematode environment,” said Kemerait in an interview with AgNet Media’s Randall Weiseman. “What I ask growers to consider is this, when you’re considering yield of your high-yielding susceptible variety versus a resistant variety that may not yield as well, was that trial conducted in a nematode infested field? If it was not, it’s really not putting that variety where we would like it to be placed to compare yield. When you put these resistant varieties in nematode-infested fields and you compare them to susceptible varieties, I think it becomes much more clear on what the value is.”
What are Nematodes?
Nematodes are microscopic worms that can devastate cotton and other row crops. Root-knot nematodes can be the most problematic because of their wide host range. They feed on cotton roots and cause swelling, or “galls,” to develop. The galls disrupt the function of the roots, which stunts the plant’s growth. Further, female nematodes feed and lay eggs at the galls.