A SUPPLY crunch is threatening to cause a spike in prices for the world’s No. 1 weedkiller, making it even more expensive for farmers to grow food.

A major supplier of an ingredient in glyphosate, an herbicide that’s widely used by corn, soy, cotton and other farmers around the world, shut down production due to mechanical failures, and repairs could take three months.

Bayer AG, the maker of Roundup, whose active ingredient is glyphosate, declared a force majeure Feb. 11, meaning it may not be able to meet its sales agreements.

That’s likely going to lead to a supply crunch, according to a an emailed statement by U.K.-based analysis company AgbioInvestor, as well as higher prices at a time when farmers are already experiencing soaring costs for everything from seeds to fertilizers. Rising production costs are part of what’s behind near-record global food prices.

“These impacts will place farmers under further pressure in a number of key markets” where costs are up, according to the statement.

Farmers are anxious. Aprosoja, an association of soybean producers in Brazil’s top-producing state Mato Grosso, sent a letter to Bayer’s chief executive officer in Brazil asking for assurances that there will be no shortages of glyphosate. Over 90 percent of soybeans grown in Brazil are genetically modified to resist glyphosate. (SD-Agencies)