A dire drought that has plagued Texas and parts of Oklahoma expanded across the key farming state of Kansas over the last week, adding to struggles of wheat farmers already dealing with weather-ravaged fields. Harvest in Kansas, the top U.S. wheat-growing state, is set to begin within weeks. But a report issued Thursday by a consortium of climatologists said the three most severe levels of drought spread across the state over the last week, with the most dire conditions concentrated in the key wheat-growing south-central and southwest parts. “It is pretty bad,” said Kansas state climatologist Mary Knapp. “For a lot of these areas… the last significant rainfall was in July of last year.” Kansas now has 50 percent of the state suffering severe levels of drought or worse, up from 41 percent last week, according to the Drought Monitor report. Just three months ago, less than 4 percent of Kansas was suffering severe drought or worse. The drought is eroding production potential at a time when every bushel counts.

Critics say it’s a chemical that could cause infertility or cancer, while others see it speeding the growth of super weeds and causing worrying changes to plants and soil. Backers say it is safe and has made a big contribution to food production. It’s glyphosate, the key – but controversial – ingredient in Roundup herbicide and the top selling weed killer used worldwide. For more than 30 years, glyphosate has been embraced for its ability to make farming easier by wiping out weeds in corn, soybean and cotton fields, and for keeping gardens and golf courses pristine. But the chemical touted as a safe, affordable and critical part of global food production, is now at a crossroads. Amid rising voices of alarm, regulators in the United States and Canada are conducting a formal review of glyphosate’s safety, lawsuits are pending and some groups are calling for a global ban.