US agrichemicals firm Monsanto is offering US soya farmers a cash incentive if they agree to use the company’s controversial dicamba-based herbicide in the 2018 planting season.

The company was offering US$6/acre back on the US$11/acre price of XtendiMax if used on Monsanto soyabeans engineered to resist the weed killer, Reuters wrote on 11 December.

However, US states had so far launched 2,708 investigations related to dicamba up to mid-October, according to statistics from the University of Missouri.

Farmers had complained that dicamba-based herbicides had caused massive crop damage after evaporating from fields and drifting to crops not resistant to them.

Monsanto insisted that XtendiMax was safe when properly applied, Reuters said, and the company was hoping to dominate the US soyabean industry with its dicamba-resistant soyabeans with the aim to compete with its rivals Bayer and BASF.

In 2016, the US Environmental Protection Agency (EPA) approved the herbicide for use on dicamba-resistant crops until 9 November 2018.

The EPA has now mandated special training for farmers using dicamba herbicides, who will need to keep records proving they have complied with label instructions.

As a result of the EPA mandate, several states were exploring restricting or banning dicamba.

North Dakota said in early December that it planned to ban dicamba after 30 June 2018 and when temperatures surpassed 29.4°C, while Missouri intended to finalise restrictions on XtendiMax after banning BASF’s dicamba herbicide Engenia statewide from 15 July 2018, said Reuters.

The training requirement was expected to drive up the costs of using dicamba, which Monsanto was aiming to combat with the cash back offer.

According to Reuters, however, some farmers felt the offer was just a ploy on Monsanto’s part to increase the sales of the herbicide.