Fumigant Use in California and an Assessment of Available Alternatives: Phase II Report on Methyl Bromide and the MITC Generators

Phase II Report

This is the fourth and final report released in a multi-part study requested by the California Department of Pesticide Regulation (DPR) to support the state’s transition toward safer and more sustainable pest management practices. The full independent, scientific, and technical assessment focused on pre-plant fumigants, specifically methyl bromide and three pesticides known as MITC generators: dazomet, metam-sodium, and metam-potassium. Consistent with CCST’s earlier reports in the series, the study found that while alternatives to these fumigants exist, no single alternative currently serves as a direct, 1:1 substitute for methyl bromide or MITC generators. The report concludes that more nursery-, crop-, and region-specific research is needed to determine how well alternatives perform at commercial scale, and identifies cost and effectiveness as significant ongoing barriers to adoption for growers.

Cal Poly Strawberry Center Director Gerald J. Holmes, PhD, served as the study’s Steering Committee Chair, with University of Idaho Professor Emeritus Alan S. Kolok, PhD, serving as Co-Chair. The four-member Steering Committee worked on this report with authors Janet C. Broome, PhD, of the University of California, Santa Cruz, and Broome Plant Health Consulting; and Kimberly Parra, MPH, PhD, of the Harvard T.H. Chan School of Public Health.