ANNUAL REPORT, 1943-44 71 



6. Infections Bronchitis. During the past year and a half the infectious 

 bronchitis control work was extended to the majority of counties in the State. 

 The Extension Service and the Division of Livestock Disease Control have con- 

 tinued to cooperate in this program. A total of 153 flocks was selected for the 

 control project. 



The production of virus material and the inoculation work were carried on in a 

 manner similar to that of the previous year. The post-inoculation reactions were 

 very favorable for the most part. In some instances no "takes" were obtained 

 because the flock was immune as the result of previous exposure. Mild reactions 

 which could not always be explained satisfactorily were obtained in some flocks. 

 S(jvcre reactions were obser\'ed when the flock was apparently in poor physical 

 condition. 



In November 1943 there were approximately 200,000 laying birds in the flocks 

 which were considered protected against infectious bronchitis virus. The results 

 of the past year further substantiate that birds immunized against infectious 

 bronchitis during their pre-ovulation stage are able to resist natural infection to 

 the degree that egg production is not interrupted. This crude but simple pro- 

 cedure for protecting comrnercial laying and breeding flocks against infectious 

 bronchitis has met with great demand by the flock owners in the State. As the 

 result of this interest, the work has been placed on a control service basis in order 

 to execute the program more effectively. However, further research is necessary 

 to improve methods of diagnosis of the disease, production of virus, and methods 

 of inoculation of the virus. 



7. Farm Department Brucellosis Control and Eradication. The laboratory 

 tested 369 bovine and 27 porcine blood samples by the standard tube agglutina- 

 tion method during the past year. 



WALTHAM FIELD STATION 



Waltham, Massachusetts 

 Ray M. Koon in Charge 



The members of the research staff of the Waltham Field Station are assigned 

 to this branch by the Departments of Botany, Entomology, Floriculture, Horti- 

 culture, and Vegetable Gardening. Refer to reports of these departments for 

 results of investigations conducted at this Station. 



Soil Testing Service. Commercial vegetable growers, mushroom growers, 

 florists, nurserymen, and vendors of loam brought in 2850 soil samples for testing 

 and consultation. 



There was a marked increase in the number of samples from home gardeners 

 due to the activity of the Victory Garden movement. From 3835 individuals 

 5626 samples of soil were submitted, making a total of 8476 samples tested. 



Testing Pressure Canner Gages. Aware that many pressure canners would 

 be put into operation for food preservation, the Field Station offered to test the 

 gages and safety valves. Ofthe 232 sent in only 85 were accurate. The remainder 

 registered from 1 to 7 pounds too low or too high. Many of the safety \-alves 

 were stuck and failed to blow off at pressures dangerous to the operator. 



Field Day. Because of the shortage of gasoline and tires, the lack of farm 

 machinery and other equipment for demonstration purposes, the annual meeting, 

 which would have been the twenty-fifth, was not held. 



