and liming the deeper layers and at the same time increasing the air capacity 

 or "breathing capacity" of these layers, not only was a larger quantity of 

 ladino clover roots developed, but also there were four to five times as many 

 roots in the 12-18" layer as there were in the normal soil at this depth. 



In the case of alfalfa, the tap root penetrated to a greater depth and the 

 quantity of fibrous roots in the 12-18" layer almost tripled. 



In field plots where a chisel tool was used to loosen compact sub-soil 

 layers, the improvement in soil structure was found to persist into the 

 second year. 



L. T. Kardos 



OTHER ACTIVE PROJECTS 



Soil Survey of Rockingham County 



W. H. Lyford 



Bacteriology 



Diagnosis and Control of Vibriosis in New Hampshire Dairy Herds 



Attempts were made to isolate strains of Vibrio fetus from cows in 

 New Hampshire dairy herds and to use these as antigens for studying the 

 prevalence of vibriosis in the state. No pure cultures of this organism 

 could be obtained from 6 fetuses submitted for culture. Apparently there 

 is little vibriosis infection at the present time in the dairy herds in this state 

 and it is difficult to obtain sufficient culture material for extensive studies. 

 The project will be terminated because of lack of culture material and 

 Vibrio fetus infected herds. 



L. W. Slanetz 



Studies on Bovine Mastitis 



Particular attention was given to the use of staphylococcal toxoid for 

 the prevention or control of staphylococcal mastitis in dairy cattle. Two ex- 

 perimental cows developed definite increases in antitoxin titers following 

 the administration of the toxoid. These cows did not develop acute mastitis 

 when injected via the teat canal with virulent strains of mastitis staphylo- 

 cocci. These organisms did produce acute mastitis when injected into these 

 cows before the toxoid was administered. Forty milking cows have been 

 given 2 or 3 injections of this toxoid and studies are in progress to deter- 

 mine the value of this immunization for preventing the development of acute 

 cases of staphylococcal mastitis or new infections in these cows. Similar 

 studies are being conducted on a group of 20 pregnant heifers injected sev- 

 eral weeks before calving. Antitoxins titers are being followed in these 

 cows. Achromycin and a combination of aureomycin, neomycin, streptomy- 

 cin and penicillin ointment are being tested for the treatment of staphylo- 

 coccal and streptococcal mastitis. 



L. W. Slanetz, F. E. Allen, G. V. Keeper 



Botany 



New Blight-Resistant Tomatoes Show Promise 



About a dozen lines of tomatoes have been selected which are highly re- 

 sistant to Phytophthora infestans, the organism which causes late blight of 



20 



