What happens if I delay too long? may absorb enough SI to eradicate infection, but the 



~ , . , . , . , j . fruit will not. Adding an adjuvant/penetrant has 



Delaying too long "» a high- to moderate-inocu- been ed ^ increase gI actiyi Qn fmit 



lum orchard can also lead to problems For example, Tbm ^ bfi new tions about SIs this r 



data from one orchard (Table 2) show that even ina n ,. , , „ ,.„ 



, , , u 11 i. 11 u Growers, consultants, and researchers are all still 



low-inoculum orchard, scab will eventually become . , ' llt _' ... 



severe if treatments are delayed too long. ] f min e abo ^ the SI f " n &i«des. In our experience, 



The first evidence of an SI control failure gener- these fungicides offer a valuable new tool for apple 



ally will be limited to fruit, with virtually no associ- disease management, and can be used in a way that 



ated foliar lesions. This failure is thought to be due compliments IPM strategies. Cost may remain an 



to the decreased uptake of SI fungicides by the waxy issue, though the 10-day delayed schedule offers an 



fruit cuticle. If coverage is borderline, leaf tissue option for keeping expenses down. 



Fruit Notes, Spring, 1991 23 



