liberal fertilization produced heavy 

 yields. 



In cooperative research with Teeri 

 and Percival in Agricultural and Bio- 

 logical Chemistry, Keener, Colovos and 

 Morrow investigated the role of vita- 

 mins A and D on the utilization of 

 energy and protein by dairy calves, 

 and the influence of the type of rough- 

 age on excretion of certain vitamins by 

 ruminants. In a search for more efficient 

 preservation of silage, they examined 

 the metabolic fate of radioactive sul- 

 phur (S35) when sulphur dioxide was 

 used as a preservative. 



Bovine mastitis, a highly conta- 

 gious and economically important 

 udder disease of cattle, was under in- 

 vestigation by L. W. Slanetz, F. E. 

 Allen and Morrow between 1938 and 

 1954. Slanetz, a bacteriologist, who 

 had received an appointment in the 

 Botany Department in 1934, later was 

 named head of the Bacteriology De- 

 partment in the College of Liberal Arts. 

 This group identified several hundred 

 strains of bacteria that caused the 

 disease. Sanitation, segregation of af- 

 fected animals and treatment with 

 antibiotics were recommended for 

 control. The disease is a problem even 

 today. 



Botany 



Station plant pathologists tradition- 

 ally have been housed in the Botany 

 Department. During the 1940s, early 

 blight was the most important disease 

 of tomatoes in New Hampshire. 

 Searching for plants resistant to the 

 disease, M. C. Richards, plant patholo- 

 gist, and S. Dunn tested many selec- 

 tions but found none resistant. Fruit 

 yield and fruit load, however, influ- 

 enced the condition. Richards investi- 

 gated leafroll, a virus disease of pota- 

 toes, and found that nitrogen nutrients 



suppressed and phosphate nutrients 

 accelerated symptom expression. He 

 evaluated fungicides for improved 

 control of early blight in potatoes, apple 

 scab, powdery mildew in muskmel- 

 ons and spur blight in raspberries. 



A. E. Rich, Botany and Plant Pathology 



Richards was named Associate 

 Dean of the College of Agriculture in 

 1950 and in 1951 A. E. Rich became 

 Plant Pathologist. Rich verified 

 Phytophthora infestans to be the caus- 

 ative organism of late blight in toma- 

 toes and potatoes, and with A. F. Yeager 

 and E. M. Meader in Horticulture be- 

 gan development of lines of tomatoes 

 resistant to the disease. Two new va- 

 rieties were named and released. He 

 demonstrated that cultivated straw- 

 berries quite generally were virus in- 

 fected resulting in a marked reduction 

 in yield. 



How to control weeds in perma- 

 nent pastures, new seedings and crop- 

 land was the problem imdertaken by 

 A. R. Hodgdon, plant taxonomist. in 

 the late 1940s and early 1950s. 

 Hodgdon had become department head 



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