| detection of resistance to fungicides, mating types and fitness of phytophthora infestans in hebei, china. | in vitro, isolates resistant to metalaxyl (m) and oxadixyl (o) of phytophthora infestans were 11.2% of 62 isolates from potato and tomato in hebei province, mean resistance factor was 15,022 fold and 24,733 fold, respectively, no isolates resistant either to cymoxanil (c) or to dimethomorph (d) were detected. on the other hand, in vivo, isolates resistant to m and o were 29.0% and 32.7%, respectively, among 217 isolates from potato plants in weichang and chongli, hebei, only one isolate resistan ... | 2002 | 12701437 |