Almond growers hoping to fumigate with 1,3-D (Telone) will need to plan even more carefully after the California Department of Pesticide Regulation (DPR) changed the rules on township caps and application windows for products that contain the active ingredient.
DPR’s new township caps for products containing 1,3-D will increase baseline annual township caps but remove the current “banking system” that allowed a higher cap in most townships. The new rules take effect Jan. 1, 2017.
New township caps of 136,000 pounds are an increase from current annual baseline levels of 90,250 pounds. For growers in the handful of townships where the cap had reverted to the baseline, the new rule will allow more Telone to be used. For the majority of townships, the current cap is 180,500 pounds due to “banking”; in essence, carryover of unused Telone. Thus, for the majority of almond growers, the 136,000 pounds mean less Telone can be applied in a year.
“This is the rare case in which a new risk assessment showed less risk than previously thought based on newer data,” said Dr. Gabriele Ludwig, director of Sustainability and Environmental Affairs at Almond Board of California. “DPR relaxed restrictions in some ways; however, it still will make it more complicated to control soilborne diseases and nematodes,” she added.
“Growers planning to fumigate with Telone in the next two years will need to plan well ahead," noted Dr. Ludwig, "and should contact their agricultural commissioner and use the Telone township accounting site to see how the new rules will impact those fumigation plans.”
To translate the township caps, the following provides the maximum number of acres that could be treated, assuming broadcast applications without a tarp at the maximum rate of 332 pounds of active ingredient/acre:
|
1,3-D cap (lbs.)
|
Max no. of acres that could be treated in township per year
|
|
90,250
|
272
|
|
136,000
|
410
|
|
180,500
|
544
|
Growers who use strip treatments and/or use appropriate tarps (e.g., TIF) can reduce the emissions accounted for by 30 to 60%, thus increasing the number of acres that can be treated within a township.
The chance of hitting the 136,000-pound township cap will depend on how many acres among the different crops within a township are treated with 1,3-D. For almonds, that will be driven by the number of older orchards that are replanted in the same calendar year.
This table illustrates township caps reached if all 25-year-old almonds orchards are replanted in the same year at the maximum treatment rates, with Telone applied only on almonds:
|
Year Planted
|
No. of townships possibly hitting cap 25 years later
|
|
1992
|
4
|
|
1997
|
24
|
|
2006
|
61
|
|
2010
|
16
|
DPR also banned the use of products containing 1,3-D in December, when soil conditions can lead to higher air concentrations. Applications in January will continue to count with a higher emissions rate, thus use more of the cap, than applications made February through November. This will make use more complicated for almond growers in the San Joaquin Valley who are managing compliance with both the volatile organic compound (VOC) rule and these new restrictions on the use of Telone.
