BIENNIAL R,P:P0RT, 1927 AND 1928 317 



4. Tlie following factors cause a low initial whip which facilitates 

 drawinf? the product at a temperature low enouf>;h to favor smooth texture: 

 increase of fat content, substitution of butter for cream, the addition of 

 .3 per cent egg yolk or of .15 per cent calcium lactate, and the addition 

 of the gelatine after cooling the mix. 



5. Sharp scraper lilades and a brine temperature .below 5°F. were 

 found essent;;il to tiie jirijper cooling of ice cream with a low overrun. 



Ut'lzatlon of New England Fruits in Frozen Dairy Products. (M. J. 

 Mack). The fruits used in this project were packed by the Department of 

 Horticultural Manufactures. Approximately 150 gallons of fruit are avail- 

 able, of which ten varieties of strawberries make up at least half. The 

 other fruits are raspberries, cherries, peaches, blueberries and i)liims. 



These fruits are now being utilized in fruit ice creams. Preliminarj' 

 tests of the flavoring ability of difl'erent varieties, optimum amounts to 

 use, r;itio of sugar to berries, treatment of the fruit, etc., are ncjw under 

 way. This work will be followed by a careful study of the effect of these 

 fruits on tlie freezing process and on important properties of the finished 

 ice cream. As yet the work has not advanced to the point where any 

 conclusions can be reached. 



DEPARTMENT OF ENTOMOLOGY 

 H. T. Fernald in Charge 



Dates of Hatching of Scale Insects and When to Spray for Them. 



(A. I. Bourne). With many scale insects the most successful treatment 

 sfiould immediately follow hatching of the eggs. To determine when this 

 time comes sufficiently beforehand to be prepared for treatment at the 

 right time is a great advantage. Data for many years have been collected 

 and compared with temperatures from the time of egg laying through 

 hatching, in an attempt to determine the total accumulated temijerature 

 to bring this about. Abnormal seasons, as they have occurred, have alsio 

 been studied and the investigation is now well in hand. 



Investigation of Materials which Promise Value in Insect Control. 

 (H. T. Fernald and A. I. Bourne). Four diff'erent types of miscible oils, 

 four "soapless" emulsions and one lubricating oil emulsion have been 

 tested for efficiency as insecticides and safetx to trees, all but one of these 

 being now on Massachusetts markets or about to be placed there. 



The miscible t)ils nnd lubricating oil emulsion gave satisfactory control 

 against the Fjuropean red mite, with the "soapless" emulsions less effective, 

 one of these last being so toxic as to cause serious injury. 



Control of Onion Thrips. ( .\. I. Bourne). An effective sjiray combin- 

 ation has been develo{)ed but dusts liavf proved ineffective. A schedule 

 of applications has been completed. 



As horse-drawn spray machinery CMunot be used in the Connecticut 

 Valley onion lields because of cultural methods, a machine to fit these con- 

 ditions has been produced. It is a power sprayer, both propelling machine 

 and develojiing pressure for spraying with a com])ressed air pump. It will 

 sustain a 2()()-lb. working pressure while covering six rows. Though this 

 outfit has given promising results, jiremature dying of onions the last 

 two years and light infestation of thrips have prevented large scale tests. 



Spray Residue Problem and Its Relation to Orchard Practices. (A. I. 



