University of Wisconsin–Madison

Category: Newsletter

Vegetable Crop Update – May 10, 2026

In this issue: Amanda Gevens, Professor & Extension Vegetable Pathologist, UW-Madison, Dept. of Plant Pathology, 608-575-3029, gevens@wisc.edu Environmental Protection Agency (EPA) Draft Endangered Species Act (ESA) Fungicide Strategy – Feedback Requested by June 29 On May 1, the EPA released its draft Fungicide Strategy to bring the Agency into compliance with its obligations under the …

Important update on Blocker fungicide in potato

In mid-December 2025, AMVAC Chemical Corporation, the manufacturers of the fungicide Blocker (pentachloronitrobenzene, PCNB), decided to stop producing Blocker 4F and 10G. In effect, this concludes production of Blocker for the future. The Blocker that is on the shelves at this time is all that will be available for future use. It is estimated that this will leave potato growers with a supply that may satisfy only 25-33% of the potato use demand in 2026.