Carbendazim-resistance of Gibberella zeae associated with fusarium head blight and its management in Jiangsu Province, China

Abstract Fusarium head blight (FHB) caused by Gibberella zeae occurs in wheat-producing areas worldwide. FHB results in substantial economic losses and produces various mycotoxins, notably the type B trichothecene (B-Trich) deoxynivalenol and its acetylated derivatives and nivalenol, as well as the sterol zearalenone, which are toxic to humans and animals, respectively. Here, 1313 (667 from conventional fields [CFs] and 646 from systematic observation fields [SOFs]), 1915 (1246 from CFs, 669 from SOFs) and 1703 (1118 from CFs, 585 from SOFs) isolates of G. zeae were collected from 37, 43 and 35 counties (cities), respectively, in Jiangsu Province in 2016–2018. The sensitivity to carbendazim (MBC) was determined, and 2-year field trials on the management of FHB severity and B-Trich contamination were conducted using 10 representative fungicides registered by the Institute for the Control of Agrochemicals, Ministry of Agriculture of China. The frequencies of MBC-resistant (R) G. zeae collected from CFs in 2016–2018 were 61.32%, 58.03% and 56.80%, respectively, and those from SOFs were 38.24%, 43.80% and 41.37%, respectively. The frequency of MBC-R G. zeae in Jiangsu Province was found to be the highest in the world, and this development of MBC resistance requires the application of alternative chemicals to fight FHB. In field trials in 2017–2018, tebuconazole and phenamacril showed >85% efficacy in the control of FHB severity and B-Trich contamination. A mixture of pyraclostrobin and tebuconazole showed >82% and G. zeae and control of FHB and B-Trich.