56 MASS. EXPERIMENT STATION BULLETIN 428 



Nature of Winter Hardiness in the Raspberry. (J. S. Bailey, A. P. French, 

 and R. A. Van Meter.) Five canes each of the varieties Marcy, Washington, 

 Taylor, Milton, Chief, and Latham were brought into the greenhouse at about 

 weekly intervals from November 7 to December 21, 1944, for forcing. 



Among the canes brought in November 7, those of the varieties Marcy, Wash- 

 ington, and Milton started in 37 to 39 days, while some of the canes of the varie- 

 ties Latham, Chief, and Taylor never did start. By November 15 all varieties 

 could be forced to grow, but the first three varieties started more readily than the 

 others. By December 1, all varieties except Chief started on the avearge in 

 from 17 to 22 days. Therefore, (1) these varieties are divided into two groups, 

 one of which can be started into growth more readily than the other; and (2) 

 for all but Chief the rest period was over by December 1 and for Chief by Decem- 

 ber 21. 



A Wheatstone bridge apparatus was set up to test the resistance of raspberry 

 canes in the hope of finding a method to tell in the field whether canes are alive 

 or dead. When live canes were tested and then killed by freezing in a cold room, 

 the resistance was less after freezing. As canes dried out the resistance increased. 

 Canes brought in from the field during the winter and tested had either a normal 

 or a very high resistance. The latter indicates that the canes had either been 

 killed by drying or had dried out between the time they were killed and the time 

 the resistance tests were made. 



ControUed-Atmosphere Storage of Apples. (L. Southwick and O. C. Roberts, 

 in cooperation with the Department of Engineering.) The'300-bushel controlled- 

 atmosphere room was filled on September 28, 1944, and opened on March 7, 

 1945. Instead of maintaining the levels of oxygen and carbon dioxide at 2 and 

 5 percent respectively, necessitating the use of a special air scrubbing apparatus, 

 it was decided to try the English system of 10 and 11 percent, which can be main- 

 tained in a tight room by the proper use of ventilation. Actually the carbon 

 dioxide level ranged mostly between 9 and 11 percent. The sum of the carbon 

 dioxide and oxygen always equalled about 21 percent which is the percentage of 

 oxygen in air. The temperature was maintained at 40°F. 



The main test was with Mcintosh from 25 individual trees. Check lots were 

 stored in the usual way around 32°F. Average firmness of the flesh as measured 

 by a pressure tester on March 6 showed no consistent differences, indicating 

 that the levels of oxygen and carbon dio.xide used were not so effective in pro- 

 longing storage life of Mcintosh apples as the levels previously used; namely, 2 

 and 5 percent. Furthermore, scald was a real factor varying from very light to 

 very severe, and averaging about 10 percent. Apples from some trees showed 

 from 50 to 75 percent visible scald on removal from the controlled-atmosphere 

 room. This was probably due to the relatively high carbon dioxide concentra- 

 tion. Only occasional scald was found on Mcintosh in the regular storage. 



Cortland apples from two orchards softened significantly less in the controlled- 

 atmosphere room than in regular cold storage, but scald was much worse. 



The possibility of positive scald control by air purification is under study. 



Comparison of Cultivation and Sod in a Bearing Orchard. (J. K. Shaw.) This 

 experiment has now a continuous record for 24 years. Certain changes of treat- 

 ment of some of the seven lO-tree plots of Mcintosh apple trees have been made 

 from time to time. In addition to the comparison between sod-nitrogen and 

 cultivation without fertilizer, the effect of hay mulch and of the addition of 

 phosphorus and potash to nitrogen have been studied. 



The sod vs. cultivation question was soon answered. Cultivation without 

 nitrogen does not maintain production. This conclusion has been supported by 



