- 5 - 



hours of harvest or treat with Stop Scald after harvest for additional protection 

 against scald. Dr. R. M. Smock in New York suggests that Stop Scald Is the 

 preferred post-harvest treatment for Rome since DPA has caused some fruit injury 

 when used at the 2-pound rate. 



Franklin W. Southwlck 



I I I I I I I I I I I I I I I I 



PRKHARVEST DROP CONTROL 



With moderate to heavy crops of apples on most of our drop susceptible 

 varieties such as Mcintosh, Delicious, Baldwin, and Rome, it is always possible 

 for us to have a rather serious preharvest drop problem. The prime factors that 

 tend to Increase the severity of fruit drop are large crop size, poor foliage due 

 to frost Injury, disease. Insect, and/or deficiencies of magnesium, potassiuui, or 

 boron Injury, high nitrogen levels in the trees at harvest time, fruit maturity 

 and high temperatures during the harvest period. Some of these factors can be 

 controlled by the grower to some degree but the Important weather factor is 

 beyond our control. 



At this time the foliage in most orchards is in good shape. Since full 

 bloom occurred after May 10 in our orchards and the mean growing season tempera- 

 tures to date have been below normal, for the most part, through July, earlier 

 than usual fruit ripening is not expected. However, the severity of the drop 

 problem is often unpredictable and one should be ready to use drop controlling 

 hormones every year. It may be possible now that Mcintosh for CA storage are 

 often spot-picked around September 10 to 15, that drop may be so slight at this 

 time that the use of NAA (naphthaleneacetlc acid) can be delayed until much of 

 the CA fruit Is picked. However, It would seem best to use NAA before harvesting 

 fruit for CA rather than take serious losses from drop. The hastened ripening 

 action from NAA Is usually very small if the fruit is picked within 7 to 10 days 

 after treatment. Also, applications of NAA (naphthaleneacetlc acid) have no 

 appreciable influence on the amount of scald developing on regular or CA stored 

 Mcintosh last year (see Table 1). 



Table 1. The Influence of preharvest drop sprays of NAA on the 

 development of storage scald In regular and CA storage 



*Fruit removed from storage on 3/21/62, 



