MANAGEMENT OF SYMPTOMS DEVELOPED AFTER INFECTION OF SCAB (VENTURIA-INAEQUALIS) IN APPLE (MALUS-DOMESTICA)

An experiment was conducted during 1986 and 1987 under controlled cond ition and during 1986-90 in orchard to evaluate the post-infection act ivity of fungicides in the management of scab [Venturia inaequalis (Co oke) Winter] Of apple (Malus domestica Borkh.). Under controlled condi tion single application of either fenarimol (Rubigan 0.04%) or hexacon azole (Anvil 0.075%) gave the lowest mean incidence of scab (0.283 and 0.293% respectively), followed by bitertanol (Baycor 0.1%). However, fenarimol proved better when applied 48, 72 and 96 hr after artificial inoculation but hexaconazole at 24, 48 and 74 hr. In the orchard, fen arimol, bitertanol, prochloraz and venturol effectively suppressed the scab symptoms. It was concluded that 2-3 post-infection sprays of fen arimol (0.04%) and bitertanol (0.1%) may be used alternatively on comm ercial scale.