138 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



After experimenting with orchard fertilizers for 15 j^ears, the 

 New York State Station has conchided that commercial fertilizers 

 are of little benefit to j'oung apple orchards growing on soils natu- 

 rally suited to apple culture, provided the orchards are well tilled, 

 well drained, and properly supplied with organic matter from stable 

 manure or from cover crops. 



The entomologist of the Kansas Station has demonstrated the 

 practicability of high temperatures as an efficient method of control 

 of insects in stored grains. The method has been successfully in- 

 stalled in several mills in the State. He has also shown that the 

 chinch bug w^inters in bunch grasses in Kansas, and that burning 

 over these areas materially reduces the attack of the chinch bug the 

 next year. In connection with inspection work carried on in co- 

 operation with the State horticultural department and provided for 

 by the State horticultural law, the Maryland Station discovered over 

 700 nests of the brown-tail moth in imported nursery plants and 

 destroyed them to prevent distribution. 



The New Hampshire Station demonstrated the possibility of con- 

 trolling the black fly in the White Mountains by treating streams 

 where these flies breed with a suitable soluble oil, which kills tne larvae 

 without injury to the trout in the stream. 



The veterinary department of the Delaware Station, in coopera- 

 tion with the Bureau of Animal Industry of this department, has 

 produced a serum with which sheep may be protected against an 

 otherwise mortal dose of anthrax bacilli and an immediate passive 

 immunity produced. In an investigation of the strongyloid para- 

 sites of calves the South Carolina Station has found that their attack 

 may be avoided by keeping animals on other than low, moist pastures. 



The Minnesota Station reports in its studies on stable ventilation 

 that the relative percentages of oxygen and carbon dioxid do not 

 seem to be of material eifect, but that the confined air seems to in- 

 fluence the kidney secretions. It was observed during the year that 

 pigs from immune sows appear to be born with very high resistance 

 to cholera. This natural immunity was found to disappear gradu- 

 &\lj, but was sufficient up to at least 5 weeks of age to make it pos- 

 sible to inoculate such pigs with very high virulent blood with an 

 unimportant percentage of loss. 



The California Station found that under California conditions the 

 use of bovo- vaccine seemed to produce some immunity against tuber- 

 culosis but to fail in protecting calves until 2^ years old. It was 

 also found that tuberculosis spreads rapidly in cattle under strictly 

 outdoor conditions. 



The dairy expert of the New York Cornell Station in his work 

 with the milking machine found that immersion of the milking parts 



