U.S. farmers and farm experts knew they’d soon lose a popular chemical used to control major crop pests. But the end has come sooner than they expected.

Bayer CropScience has announced it would end production of methyl isocyanate, or MIC, at its factory in West Virginia. It will close this factory and one in Georgia. MIC is used to make Temik, which Georgia farmers have used for four decades to control insects and nematodes on major row-crops like peanuts, cotton and soybeans.

Last summer, the company agreed with the U.S. Environmental Protection Agency to phase-out Temik production by 2014 and its use by 2018. The agreement followed a new dietary risk assessment conducted by the agency.

But an on-going lawsuit surrounding the Bayer CropScience plant in West Virginia has delayed production at that plant, enough to prevent the company from producing MIC for this year’s growing season, according to a prepared statement by the company.

Farmers now will only be able to use the Temik that is stockpiled. And there is likely only 40 percent available of what would be needed in a typical year, said Bob Kemerait, a plant pathologist with University of Georgia Cooperative Extension, located in Tifton, Ga.