Experiments were conducted over a 5-year period to determine whether superficial scald in Queensland grown and cool-stored Granny Smith apples could be controlled by chemical means. Diphenylamine applied prior to storage either as a dip or incorporated in paper wraps effectively controlled scald over a wide range of maturities and under conditions of normal atmosphere and controlled atmosphere storage. Scald control was effected even in atmospheres containing high concentrations of carbon dioxide, but when 10 per cent. carbon dioxide was present in the, storage atmosphere, oiled paper wraps containing 15 per cent. mineral oil in addition to the diphenylamine treatment were necessary to obtain complete control. Low concentrations of diphenylaimine in addition to oiled paper wraps containing 15 per cent. mineral oil yielded control of the disorder equal to higher concentrations of the compound used alone. Though control was effected irrespective of the maturity of the fruit at the time of picking, other storage disorders increased if very immature fruit was stored. Diphenylamine appeared to have some control on the incidence of internal breakdown in the experimental fruit. A number of other chemical compounds were tested for their scald-controlling properties and five were found to give a considerable measure of control.

v | Kirjasto Aj-k | Chemical weed control in fruit crops

v | ok | Kirjasto Aj-k | Rikkaruohojen kemiallinen torjunta hedelmä- ja marjatarhoissa

Blossom blighting is of no practical importance in Queensland. Most fruit infections appear to occur during a period of about a month before harvest. Control of brown rot in dessert peaches was obtained with three sprays of captan at intervals of two weeks, the last being immediately before harvest.