AS SPRING arrives, the hills of Languedoc in southern France turn green with the leaves of grapevines. This is helped along by chemicals—lots of them, confides a winemaker based near the town of Thuir in the Pyrenees. In their absence, vineyards would need natural fertilisers and to be weeded by hand, both costly. French farmers use more chemicals than anyone else in Europe: 65,000 tonnes of pesticides alone each year.

Even the smallest of vine-growers has an interest in a series of takeovers proposed between their chemicals suppliers. After a decade without any big deals, since 2015 three mega-mergers, collectively worth around $240bn, have been proposed. When they were first announced, many doubted that regulators would allow the mergers because of competition worries. If all three proceed, as now seems likely, four companies will produce 70% of the world’s pesticides instead of six today.

The first mega-merger, announced in December 2015, was between Dow Chemical and...Continue reading