ANNUAL REPORT, 1941 43 



berries from vines just outside the tanlcs or from vines on slightly higher ground. 

 Berries of the Early Black variety showed the greatest difference. Those from 

 vines inside the tank averaged 158 to the cup (J^ pt.); from vines just outside, 

 118 (average of 93 counts); and from vines on slightly higher ground, 110 (20 

 counts). The average number of berries per cup for the other two varieties was as 

 follows: Howes, inside tank 115, outside near tank 105, outside on slightly higher 

 ground 100; McFarlins, inside tank 94, outside near tank 94, on slightly higher 

 ground 84. Many berries failed to grow to a size large enough to be picked. The 

 proportion of these berries was greater from vines inside the tanks or from vines 

 outside near the tanks than from vines on higher ground. 



The reduction in the size of picked fruits and the failure of berries to grow 

 to a size large enough to be picked probably is due to an inadequate food supply 

 during the summer because of injury to the leaves of the preceding season which 

 reduced their capacity to synthesize carbohydrates. Vines of all three varieties 

 inside the tanks lost more of their old leaves than did vines outside. This was 

 true especially of Early Black which lost nearly all the old leaves from vines 

 inside the tank. Even when old leaves remained on the vines, many of them were 

 injured and probably their effectiveness in the formation of carbohydrates was 

 greatly reduced. 



The following conclusions are drawn: Injury to cranberry vines occurs when 

 the dissolved-oxygen content of the water falls below 2 cc. per liter. This happens 

 apparently only when the ice on a winter-flooded bog is covered with snow, 

 which excludes light and thereby prevents photosynthesis and the resultant 

 liberation of oxygen which ordinarily keeps the oxygen content of the water 

 high enough to prevent injury. The injurious effect on cranberry vines of a lack 

 of oxygen for several days to a few weeks is shown ultimately in the reduction 

 of the crop. Reduced yields are the direct result of (1) reduction in the number of 

 flowers setting fruit, (2) death of flower buds and flowering uprights, and (3) re- 

 duction in the size of fruits, both those harvested and those too small to pick. 



DEPARTMENT OF DAIRY INDUSTRY 



J. H. Frandsen in Charge 



Studies on Chocolate-Flavored Milk. (W. S. Mueller.) The study of choc- 

 olate-flavored milk, with especial emphasis on its nutritive value, continues to 

 be a major project in this department. For a long time it had been assumed 

 that the well-known nutritive properties of plain milk were also present in choc- 

 olate-flavored milk. In 1937 it was discovered that milk containing 2.5 percent 

 or more of cocoa was not equal in nutritive value to plain milk, when fed to white 

 rats. Since then experiments have been in progress to learn more about the 

 various constituents of cocoa and their possible effects upon the nutritive value 

 of the milk. In addition to the nutritional studies, investigations on improving 

 the method for processing chocolate milk are in progress. 



1. The Effect of Cocoa Upon Digestibility of Milk Proteins. (L. D. Lipman 

 and W. S. Mueller.) The addition of cocoa to whole milk powder in quantity 

 equivalent to approximately 3.6 percent by weight on a fluid milk basis reduced 

 the digestibility of the milk protein 7.8 percent. The kind of cocoa, Dutch or 

 American-process, and the inclusion of 7.1 percent of cocoa fat in the ration, 

 did not significantly affect the percentage reduction. Proteins of the Dutch and 

 American-process cocoa were found to be 38.1 and 44.5 percent digestible, re- 

 spectively. The results of this study were published in the Journal of Dairy 

 Science 24, May 1941. 



