Extension Granted For Use Of Nemacur (Fenamiphos) September 30, 2014 By John H. Foy

Irregular-shaped areas of weak, thin turf that show very limited or no response to fertilizer and irrigation inputs are symptomatic of moderate- to high-level infestations of plant-parasitic nematodes. This soilborne pest has become an increasing concern on golf courses throughout Florida because of limitations in available treatment options.

Nematodes are unsegmented round worms. While all nematodes are not bad, there are several species of these microscopic worms that are parasitic pests of turfgrass. Plant-parasitic nematode species have a stylet, or mouth-spear, that resembles a hypodermic needle and is used to penetrate and feed on the regionalUpdateContent system of turfgrass and other plants. This feeding activity, and the resulting damage, reduces the ability of turf to obtain water and nutrients from the soil. As nematode populations increase, a point may be reached where turf health is negatively impacted and an acceptable level of quality can no longer be provided. Environmental conditions in Florida are very favorable to the proliferation of nematodes and various other pests. The use of nematicides, especially on putting greens, has been considered a necessary measure for being able to maintain acceptable turf quality for many courses in Florida.

For various reasons, many of the most effective nematicides have been withdrawn from the market. Fenamiphos, the active ingredient in Nemacur, is no longer being produced or sold in the United States. As part of the original phase-out process of fenamiphos, existing supplies could continue to be used until exhausted. Unfortunately, due to a change in the Federal Register, 76(193):61690-61694, the EPA was requiring that all stocks of Nemacur products be used no later than Oct. 6, 2014. However, in response to a request from the Golf Course Superintendents Association of America (GCSAA), the EPA has granted an extension on the use of fenamiphos products labeled for use on golf courses until Oct. 6, 2017. This is certainly good news for courses that still have fenamiphos products in their inventory. For additional information on nematode management and treatment options, please seeNematode Management for Golf Courses in Florida, by Dr. Billy Crow.

Source: John Foy (

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