52 MASS. EXPERIMENT STATION BULLETIN 398 



Storage of Apples in Modified Atmospheres. (L. Southwick and O. C. Roberts, 

 in cooperation with the Department of Engineering.) On account of mechanical 

 difficulties with the storage room the test could not be started until November 27. 

 The oxygen percentage steadily decreased, reaching 2 percent in three weeks, 

 and thereafter the room atmosphere was maintained at 1 to 2.5 percent oxygen 

 and around 8 percent carbon dioxide by periodical "washing" out of the latter 

 and by infrequent partial ventilation to allow oxygen build-up. There is danger 

 of anaerobic respiration, development of off-fiavors, and death of apples under 

 long-continued oxygen levels below 1 percent. The room was opened on March 

 17 and the apples removed. 



Cortland had scalded slightly to severely even when wrapped in oiled paper, 

 indicating that modified atmosphere storage is entirely unsuited to this variety. 

 The Golden Delicious were in excellent condition with practically no shriveling, 

 indicating that for this variety this type of storage ma}' be especially suitable. 

 The relative humidit\- rem.ained high throughout the storage period and this is 

 particularly important in successful storage of Golden Delicious. The Mcintosh 

 were variable, with condition good but quality onh fair. They were already 

 mature to slightly over-mature when the storage began to function properly late 

 in December and, under these conditions, they came through better than ex- 

 pected. 



On September 25, 1942, the room was again filled and at the time of writing 

 (November 20) the storage appears to be functioning properly. 



Nutrition of the High-bush Blueberry, Especially in Relation to Soil Reaction. 

 {]. S. Bailey.) A mixture of equal parts by weight of sulfur and ferrous sulfate 

 was found to be a good remedy for iron chlorosis. The amount required depends 

 on the acidity and buffering action of the soil and condition of the plant. 



Blueberry Culture. (J. S. Baile\ .) Buds set in 1941 ga\e a small percentage 

 of successes. Winter protection of the buds b\- sawdust was of little value be- 

 cause the buds failed to "take" before the sawdust was applied. Bushes were 

 budded in 1942 at weekly intervals from July 25 to September 3 to observe the 

 effect of time of budding. Although some buds have already died, the "take" 

 seems to be much better than last year. 



Four new varieties, Atlantic, Burlington, Weymouth, and No. 73, have recently 

 been added to the collection, which includes all the improved varieties now in 

 cultivation. 



Preharvest Dropping of Apples. (L. Southwick.) Drop-control sprays and 

 dusts were used on Mcintosh, Duchess, and Wealthy. 



With Duchess, which responded markedly to drop-control sprays in 1940, the 

 results with dusts were disappointing although the three dusts used were partially 

 effective. Two commercial materials applied as sprays were almost equally 

 effective and significantly more effective than the dusts. 



With Wealthy, which responded poorly to "hormone" sprays in 1940, dusts 

 were relatively ineffective as w'as also one standard spray. With the other spray 

 applications, the degree to which drop was controlled was correlated with the 

 concentration of active chemical. These results support the conclusion reached 

 previously that under Massachusetts conditions the stronger sprays are likely to 

 be more effective. The added cost of more concentrated sprats ma}' or may not 

 prove profitable. 



With Mcintosh, results were variable, but in general dusts were more satis- 

 factory than with Duchess or Wealth}\ The three commercial dusts varied 

 somewhat in apparent effectiveness but more than one season's tests are neces- 

 sary to confirm that differential results are really due to "brand." Repeat 



