Studies of arsenic spray residues on apples

Abstract

During the 1954-55 and 1955-56 seasons two trials were carried out in the Stanthorpe district to obtain data on arsenic spray residues on apples. It is evident from these trials that lead arsenate is not weathered appreciably from the fruit, and durinq the season the gradual reduction in arsenic residue as p.p.m. As2O3 is largely the result of fruit growth. One 3 Ib./100 gal. spray applied to the variety Granny Smith at a dosage rate of 1 1/4 gal. per tree in late November resulted in residues of less than 0.6 p.p.m. at early harvest in early January, and at the same dosage rate and timings the mean residue from a double strength spray was 1.46 p.p.m.