BIENNIAL REPORT, 1927 AND 1928 341 



on 321 flocks ;ind 138 flocks, comprising 80,829 birds, were reported 

 negative. 



Based on the 1925 jionitry population of Massaciiusetts, it is estimated 

 that 9.39 per cent of tiie chickens in the State were tested in 1927-28 as 

 compared with ().27 per cent in 1926-27. Using the same comparison, 3. 98 

 per cent of the chickens of the State were in non-reacting flocks in 1927-28, 

 as compared with 1.98 per cent in 1926-27. 



Following the 1927-28 testing season a questionnaire was sent to the 

 321 flock owners for whom testing had been done. Some of the informa- 

 tion obtained from the 239 replies is presented. 



Eflcct of bleeding on egg production: one i^erson reported egg pro- 

 duction increased by bleeding, 166 reported "no effect", and 72 reported 

 losses from to 50 per cent, due either to bleeding or to handling of the 

 birds or due to both. 



Mortality traceable to blood collecting: thirteen persons reported a 

 total of 50 birds lost from hemorrhage following the withdrawal of blood. 

 Four persons reported the death of 12 birds due to causes other than 

 hemorrhage but indirectly traceable either to bleeding or to handling of 

 the birds. A total of 62 birds or .026 per cent of all birds bled during the 

 1927-28 season were reported having died as a result of blood collection. 



Kinds of disinfectants used: twenty-nine brands of disinfectants were 

 reported as being used for spraying the hen houses after the removal 

 of reactors. Seven of these are included on the U. S. Department of Agri- 

 culture B. A. I. ai)proved list, (B. A. I. Circular Letter 1508) and ninety- 

 six poultrymen were using these approved disinfectants. 



SPECIAL TOBACCO INVESTIGATIONS 



Conducted by the Bureau of Plant Industry, United States Department 

 of Agriculture, in cooperation with the Massachusetts Agricultural Ex- 

 periment Station. 



H. F. Murw.'n, U. S. D. A., in Charge 



Brown Root-Rot. (H. F. Murwin). IMot work is being conducted at 

 Whately to study comparative eflfects of i)receding crops on the growth 

 of tobacco both in healthy and in infested soil with two acidities in each 

 case. It has been demonstrated in these experiments that certain crops 

 may not only inhibit recovery from brown root-rot in infested soil but 

 may actually bring about this condition in liealtiiy soil. The crops used 

 were alfalfa, corn, clover, tobacco, tiniotliv', soy beans, ])ot.'itoes, oats, 

 field peas and two tyi)es of fallow. Tiiese crops were grow n two successive 

 years and followed by tobacco in each case. Toliacco made a good 

 growth following tobacco, fallow and oats on both healthy and infested 

 soil. The detrimental efl'ect of corn, alfalfa, clover, timothy and soy 

 beans on the tobacco crop was quite marked in both cases and the efl'ect 

 of potatoes and field jieas was intermediate. To date no beneficial effect 

 on tobacco has followed any crop except oats, and even here the yield was 

 no greater than in the case of tobacco following tobacco or f;i!low. Brown 

 root-rot has never resulted from continuous culture of tobacco on healthy 

 soil in thefe exjieriments, and the yield of tobacco has invariably im- 

 proved from one year to the next with continuous culture on infested soil. 

 The above results were obtained on rather acid soil, and no data on crop 

 effects iiave been obtained from the less acid plots to date. 



