Tom Isakeit, AgriLife Extension plant pathologist, continues to “fine-tune” a product that has proven effective against one of the most stubborn of cotton diseases, root rot.

Topguard fungicide received a Section 18 emergency exemption for use in Texas cotton in 2012. That exemption has been extended into 2013 with hopes a full label soon will be issued.

The current application method is with a T-band at planting. “We’re evaluating in-furrow application and assessing phytotoxicity,” he says. Rainfall soon after planting is a factor in phytotoxicity.

Adequate moisture shortly after planting is also important for product efficacy, Isakeit says, with three-fourths inch of water needed within three to five days after planting. “If there is no rain, we get no benefit — but we also see little disease.”

Test results from 2012 plots were largely indeterminate because of drought, he says. Disease presence was inconsequential in many research plots. He notes, however, that areas where nozzles were clogged and limited fungicide applications “showed how well the product works.

“We are pushing for proper IPM strategy with the product to maintain efficacy. We need to rotate; a monoculture also leads to other problems, such as nematode infestations.”