ANNUAL REPORT, 1938 45 



very little control was obtained. Copper h} dro 40, on the one bog on which it was 

 used, was only a little less effective than Bordeaux with soap, or than Cuprocide, 

 as judged by the amount of rot present at picking time; but as the berries were 

 held in storage, spoilage proceeded more rapidly in those from plots sprayed with 

 copper hydro 40 than in those plots on which the other sprays had been used. 

 Cuprocide 1 pound to 50 gallons with 1 quart of lethane and 2 quarts of soluble 

 cottonseed oil was much less effective in rot control than the Cuprocide-bentonite 

 spray or than Bordeaux. When the Cuprocide was reduced to Yi pound with the 

 same amounts of other materials in the spray, there was at least as much rot in 

 the berries from sprayed plots as in the berries from the checks. One pound of 

 Cuprocide 54 with 1 quart of soluble cottonseed oil in 50 gallons of water had very 

 little effect on rot control. Fungatox, a prepared liquid red copper oxide, used 

 at the rate either of 1 pint or of 1 quart to 50 gallons of water, not only failed 

 to control rot but in most instances increased the amount of rot as compared with 

 that in check plots. 



The best control of fruit rots by any spray used was obtained with a modified 

 Bordeaux which contained some zinc arsenite. Four different formulas (two of 

 the four also with monocalcium arsenite) were tested on a few small plots on the 

 State Bog. Of the four, a 5-3-50 Bordeaux to which 1 pound of zinc arsenite was 

 added reduced the rot to about one-half of that obtained by the use of regular 

 5-2-50 Bordeaux. This formula appears to be worthy of further tests. 



Leaf samples were collected from sprayed plots, after each of two applications 

 given, to determine the distribution and total content of the spray residue. 

 On all plots which had been sprayed with Bordeaux or with the Cuprocide- 

 bentonite mixture the copper content of the spray residue varied between 0.5 

 and 0.8 mg. per gram of leaf sample. Variations within this range appeared to 

 have no effect on rot control. On plots on which there had been little or no rot 

 control the total copper content of the spray residue was very low, usually 0.1 

 mg. or less per gram of leaf sample, and tests for distribution also showed little 

 or no copper present. 



Blueberry Disease Investigations. (H. F. Bergman.) In a preliminary experi- 

 ment on the control of the mummy berry disease (Sclerotinia) of blueberries two 

 applications of Bordeaux 5-2-50, one just before the flowers opened and the other 

 after the petals had fallen from most of the flowers, appeared to be effective as 

 hardly any "mummies" were found after spraying. More than the usual propor- 

 tion of mummied berries were produced on unsprayed bushes near by. 



Observations made in the fall on the susceptibility of blueberry varieties to 

 powdery mildew showed that Pioneer is clearly the most susceptible. Cabot, 

 Wareham and Rubel follow in the order named. Katherine and Harding appear 

 to be the most resistant of all varieties now grown in Massachusetts. Concord 

 and Jersey appear to be somewhat less susceptible than Rubel and somewhat 

 more susceptible than Rancocas and Stanley, which approach Harding and 

 Katherine in resistance. 



DEPARTMENT OF DAIRY INDUSTRY 

 J. H. Frandsen in Charge 



Improving the Flavor and Keeping Properties of Milk and Some of Its Products. 



(W. S. Mueller and M. J. Mack.) This investigation has been continued from the 

 previous year by studying the antioxidative and othe.- properties of various cereal 

 flours: Oat (finely milled), whole oat, corn (maize), bleached wheat, whole wheat, 

 barle}', rye, and rice. Studies with water solutions of these various flours showed 



