THE "SOFT Mcintosh problem" 



W.J. Bramlage and W.J. Lord 

 Department o£ Plant and Soil Sciences 



Once again, in 1973-74, the "soft Mcintosh problem" was very 

 serious in the Northeast, The problem is that when Mcintosh are 

 removed from CA storage in late spring, they are or rapidly become 

 excessively soft easily indented by finger pressure. The re- 

 tail market cannot accept such fruit, and large economic losses 

 occur. 



In 1973, Dr. R.M. Smock discussed this problem at the New Eng- 

 land Fruit Meetings ( Proc. Mass. Fruit Growers ' Assn . 79:97-102). 

 He pointed out that there are many causes of soft apples, including 

 large fruit, high nitrogen, low calcium, over pruning, stop-drop 

 sprays, late picking, delayed storage, slow cooling, high storage 

 temperature, poor air distribution, slow Ot drop in CA, and over- 

 storage. An individual grower may have a soft Mac problem" due 

 to any one of these factors, or any combination of them. 



When the problem is widespread throughout the region, however, a 

 basic problem seems to exist. Dr. Smock discussed several such pos- 

 sibilities. The frequent recurrence of the problem corresponds with 

 the widespread adoption of Alar* treatments, and therefore, some 

 have implicated Alar* as the cause of the problem. Smock pointed 

 out that if misused. Alar* could indirectly be a cause: Alar*- 

 treated fruit should be harvested at about the same time as untreated 

 fruit, and if their harvest is delayed significantly, these fruit 

 will not hold up in storage^ But if Alar* is properly used, there 

 is no basis for blaming the "soft Mac problem" on it. (We shall re- 

 turn to this question later.) Is Ethrel* a cause of the problem? 

 Dr. Smock pointed out that it could be, if misused. Mcintosh re- 

 spond explosively to high concentrations of Ethrel*. But if used 

 properly, Ethrel* has only a small effect on softening. (See the 

 accompanying article.) 



Smock reported that Dr. G.D. Blanpied has studied 20 years of 

 weather data from New York and has found a strong correlation be- 

 tween soft apples and dry periods in the summer followed by heavy 

 rains and warm weather prior to harvest. Smock and Blanpied followed 

 this up with an experiment that demonstrated this effect on Mcintosh 

 firmness. In 1973, we had a period of dry weather and a period of 

 extremely hot weather prior to harvest that almost certainly caused 

 some fruit softening. It appears that growers should carefully ob- 

 serve the weather pattern during the season, and if a dry period 

 is followed by a hot, wet period, the probability of a "soft Mac 

 problem" is high. Growers should then observe fruit carefully dur- 

 ing storage and watch for signs of excessive softening. 



*Trade Name 



