Department of Pesticide Regulation

CLASSIFICATION OF CERTAIN NITROGEN-BASED FERTILIZER COMPOUNDS USED POST-DORMANT FOR INFLUENCING BUD BREAK AS NON-PESTICIDES

The practice of using certain nitrogen-based fertilizers to influence bud break in agricultural crops has been ongoing for some time. The Department of Pesticide Regulation (DPR) became involved in the mid-1990s. Since that time, there have been discussions about the mode of action and whether fertilizers used for this purpose required registration as a pesticide plant growth regulator (PGR).

The U.S. Environmental Protection Agency has clarified its position and concluded that influencing bud break is not a PGR effect and these fertilizers are not pesticides when used in this manner. DPR has no alternative but to adopt this interpretation. The U.S. Environmental Protection Agency further states that making claims for PGR effects for these fertilizers would be a violation of the Federal Insecticide, Fungicide, and Rodenticide Act.

PGR products currently registered for this use remain registered and continue to fall under the oversight of DPR's pesticide regulatory program, as described in the enclosed document.

cc:   Mr. Steve Mauck, California Department of Food and Agriculture (w/Enclosure)
        Mr. Daniel J. Merkley, Agricultural Commissioner Liaison (w/Enclosure)