Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi, 110 012, India
1Present address: Indian Institue of Horticultural Research, Hessaraghatta, Bangalore.
Online published on 15 December, 2011.
The fungitoxicity of twenty O, O-bisaryl isopropyl phosphonates aganst four important fungi, viz. H. oryzae, P. oryzae, A. alternate and F. solani was determined. Of these O, O-bis (2,4,5-trichlorophenyl)-and O, O-bis (pentachlorophenyl) isopropylphosphonates exhibited the highest activity. Structure-activity relationship of the phosphonates showed that changes in hydrophobicity of substituents with the phenyl ring (#x03A3;π) and molar refractivity of substituents at the para-position of the phenyl ring [MR (p)] accounted for the major percentage of variation in the fungicidal activity exhibited by the members of the series against above fungi.
