From Big Six to Big Four (2019)
OECD study sheds light on concentration and competition in seed markets.
The Big Six, as described in the wiki on DuPont
"On the other hand, if Monsanto and Bayer, the 1st and 3rd largest biotech and seed firms, together with Dow and DuPont being the 4th and 5th largest biotechnology and seed companies in the world respectively, both went through with the mergers, the so-called "Big Six" in the industry would control 63% of the global seed market and 76% of the global agriculture chemical market."