A long history with DMDS
Husain Ajwa, a University of California Cooperative Extension soil and water specialist based in Salinas, has conducted trials using the active ingredient in Paladin—DMDS—for several years.
During the past two years, he compared tankmixes of DMDS and chloropicrin with a 57:43 methyl bromide-chloride blend. All treatments were applied under a TIF plastic mulch in strawberries.
Altogether, Ajwa had 27 different treatments looking at different rates using deep-shank and drip application methods.
Some of the DMDS-pic rates were as good or better than those of methyl bromide-pic, he says.
Ajwa credited VIF and TIF for part of DMDS’ performance.
“In the old days, we tested DMDS under standard poly tarps, and we had variable results,” he says.
Ajwa says California growers are interested in Paladin because of restrictions placed on Telone.
“The growers are interested in it for one simple reason—we’re exceeding big time the township caps for Telone,” he says.
Ajwa was referring to township limits on the amount of Telone that can be applied imposed by the California Air Resources Board.
The Watsonville, Calif., area is heavily devoted to strawberries, a crop planted on ground typically fumigated annually. Until the caps were implemented, area growers relied heavily on Telone/chloropicrin blends as methyl bromide replacements.
The caps stem from an incident in the 1990s when air monitoring equipment in California’s Central Valley detected Telone at above-threshold levels.
As part of a program to bring the fumigant back into the California market, Dow AgroSciences, the product registrant, had to agree to use limits in each township.