ANNUAL REPORT, 1940 97 



cannot be much alleviated though such soils should obviously be avoided 

 in planting new orchards. 



In 1939 the use of hormones was suggested and limited trials made 

 that year gave some encouragement that they might have value. In 1940 

 several commercial preparations carrying these hormones came on the 

 market, and the manufacturers supplied these materials which, with the 

 pure hormone naphthalene acetic acid, were used in more extended tests. 

 The usual concentration was 10 parts per million, but lower concentra- 

 tions, and in one case a higher concentration, were used. Unsprayed check 

 trees were used in all cases. Comparisons were made in nine orchard 

 blocks on Mcintosh, Baldwin, Wealthj^, Duchess, and an unknown variety 

 which always drops badly. Drops from each tree were gathered and 

 counted, generally daily, and the numbers of apples picked were calcu- 

 lated. With Duchess and the unknown variety the spray was very' 

 effective, holding the apples until past the proper picking time while apples 

 on the checks dropped heavily. Witli Wealthy and Baldwin the materia! 

 was not very effective. 



Most of the comparisons were on Mcintosh, and effectiveness varied 

 in the different tests. It appeared only on computation of the actual per- 

 centage of apples dropping. In some cases the effect was very small and 

 in others it was marked, apparently preventing as much as 60 percent of 

 the drop when picking was delayed. The effect appeare,d first about two 

 or three days after the application and continued around ten to twelve 

 days. About 15 to 35 gallons per tree, according to its size and crop, 

 were applied. Concentrations of less than 10 p. p.m. seemed less effective, 

 suggesting that until further investigation, it is unwise to apply at less 

 than recommended strength. 



It is doubtful whether many of the trials on Mcintosh checked drop 

 enough to be commercially profitable. It should be remembered that 

 drop was much less in 1940 than usual. It is probable that in a year of 

 normal or excessive drop the use of hormones would be more profitable. 



The size of the crop on the trees is perhaps the most important factor 

 in determining the profit from hormone spraying. With a heavy crop 

 the number of bushels saved would be larger while the expense involved 

 would be little more than with a light crop. 



Our present feeling is that a Mcintosh grower should have a supply 

 of the material on hand and if warm moist weather prevails as harvest 

 approaches, and especially if apples have not sized and colored sufficiently, 

 he should apply it as soon as dropping becomes marked, even if he has 

 to take some of his best pickers for the job. Our experience this year 

 does not warrant any preference for any of the commercial preparations. 

 All are presumed to carry practically the same content of hormone and 

 differ only in the carrier, which may or may not affect the efTectiveness 

 of the hormone. 



Miscellaneous Work 



The Use of Peat in Planting Apple Trees. In May 1939, a small ex- 

 periment was set up to test the effect of granulated peat on newly set 

 trees. Twenty-six trees (mostly one-year whips) were planted in the 

 usual manner. For an equal number of trees, each tree being paired with 

 a check tree, the soil for planting was thoroughly mixed, 50-50, with 

 twelve quarts of wet peat prior to setting each tree. Several varieties 

 and rootstocks were represented. The peat had been used during one 

 season for propagation purposes and was not strictly comparable to fresh 



