Phenylpyrrole fungicide for seed treatment; structurally related to pyrrolnitrin, q.v. Prepd (not claimed): K. Ohkuma et al., GB 2024824; eidem, US 4229465 (both 1980 to Nippon Soda). Process: P. Martin, EP 174910; idem, US 4812580 (1986, 1989 both to Ciba-Geigy). Comprehensive description: D. Nevill et al., Brighton Crop Prot. Conf. - Pests Dis. 1988, 65-72. Field trials in potatoes: A. J. Leadbeater, W. W. Kirk, ibid. 1992, 657. Mechanism of action study: A. B. K. Jespers, M. A. De Waard, Pestic. Biochem. Physiol. 49, 53 (1994).