Management of symptoms developed after infection of scab (Venturia inaequalis) in apple (Malus domestica)

Abstract

An experiment was conducted during 1986 and 1987 under controlled condition and during 1986-90 in orchard to evaluate !he post-infection. activity of fungicides in the management of scab [Venturia inaequalis (Cooke) Winter] of apple, (Malus domestica Borkh.). Under controlled condition single application of either fenarimol (Rubigan 0.04%) or hexaconazole (Anvil 0.075%) gave the lowest mean incidence of scab (0.283 and 0.293% respeotively); followed by bitertanol (Baycor 0.1%).However,  fenarimol proved better when applied 48. 72 and 96 hr after artificial inoculation but beucbnazole at 24,48
and 74 hr. In the orchard, fenarimol, pitertanol, prochloraz and venturol effectively suppressed the scab symptoms. It was concluded that 2-3 post-infection sprays of fenarimol (0.04%) and bitertanol (0.1 %) may be used alternatively on Commercial scale.