Woodward also commented on cotton seedling diseases, which are typically worse under cool, wet conditions. The last three growing seasons have been hot and dry, but Woodward said disease pressure has also been heavy. “With center pivot units running continually, we lower the soil temperature and provide a favorable environment for disease in susceptible varieties. The micro climate has been a factor.”

He said abiotic stress—drought and heat—has resulted in more disease pressure.

Weather makes a difference. “We had good conditions in 2007 to test seedling disease and we showed the value of seed treatments.”

Cotton farmers who plant early to reduce later risks or to cover a large number of acres may want to consider seed treatment. “We also see the value of ‘premium treatments’ with extended risk,” he said. Even with the advantage of premium treatments in protecting the crop, Woodward said a yield boost is not typical.

“We are happy with the standard products if conditions warrant,” he said. With more risk, premium treatment packages may be better options.

He said cotton root rot is not a common problem in the Texas High Plains but may show up in the Rolling Plains and can be a devastating disease causing heavy yield loss and harvest problems as cotton stalks pull loose from the soil and clog up harvesters.

Contributing to the problem is the wide range of pathogen hosts. Woodward said as many as 2,500 plants may serve as hosts to the root rot pathogen. Until recently, cotton farmers were limited to rotation as a management strategy. That can still be part of an overall management plan, but Texas A&M AgriLife Extension pathologist Tom Isakeit, College Station, has identified a fungicide, Topguard (flutriafol), which offers control of the disease.

“Trials have shown significant reduction in the amount of the disease and researchers are seeing substantial yield increases, from 300 to 400 pounds per acre. Harvest efficiency is also improved.”

Ongoing studies are looking at application methods, timing, rates and potential for phytotoxicity.

Woodward said with either a disease or a nematode problem, cotton farmers should be alert to crop progress and possible problems. “Know your enemy,” he said. “Knowing is half the battle.”

 

More on Southwest crop production:

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