32 MASS. EXPERIMENT STATION BULLETIN 355 



spring cropping season in comparison with their usual varieties, which are sus- 

 ceptible to leaf mold, and as a source of seed for large-scale growing in the critical 

 fall cropping season, should the tomato prove acceptable. The new leaf mold 

 resistant tomato has been named Bay State. 



Carnation Blight Caused by Alternaria dianthi S. & H. (E. F. Guba, Waltham.) 

 No results to report. 



In cooperation with Prof. H. E. White, Floriculture, the behavior of varieties 

 of carnation to branch rot and wilt caused by the fungus Fusarium dianthi Prill. 

 & Delacr., a serious parallel problem, has been noted. Numerous crosses among 

 resistant varieties, and between resistant varieties and Ward, have been made 

 in an effort to combine disease resistance with desirable quality and color. 



Diseases of Trees in Massachusetts. (M. A. McKenzieand A. Vincent Osmun.) 

 Field and laboratory studies of tree diseases during 1938 accorded special atten- 

 tion to the condition of elms, particularly whether the Dutch elm disease was 

 present in Massachusetts. Thus far no elms in the State have been found to 

 be affected by the Dutch elm disease, but the progressive spread of infection to 

 a point about ten miles from the southwestern corner of the State is cause for 

 serious alarm. This situation, in connection with the fact that the known insect 

 carriers of the disease are present in the direct path of its advance in New York 

 toward the western part of Massachusetts, creates a serious problem. The im- 

 portance of timely and adequate action cannot be emphasized too strongly. 

 Fortunately Massachusetts is in a position to profit by the fundamental progress 

 made elsewhere in the operation of protective programs. In spite of the fact 

 that an increased number of diseased trees has been found during the past year 

 in some infested areas, there are in all cases encouraging indications that the 

 eradication program is meeting with success in the face of many obstacles. The 

 disease is now so close to Massachusetts, and the opportunity for its spread within 

 the State so significant, that concerted effort is urgently needed. 



During the past four years the Shade Tree Laboratory has received more than 

 6,700 specimens for diagnosis relative to disease. In 1938, laboratory studies of 

 more than 1,000 specimens, including collections by four field men, were com- 

 pleted by microscopical and cultural methods. During the year 69 diseases of 

 34 hosts, including 12 diseases of elm, were studied. 



Particular attention was given to the study of those elm diseases which are 

 distinguishable from the Dutch elm disease only by cultural methods. Experi- 

 ments on potted elms inoculated with vascular fungus parasites have been con- 

 tinued in the greenhouse. A manuscript on "Cephalosporium Elm Wilt in 

 Massachusetts" has been prepared, with Miss Eunice M. Johnson, Institutional 

 Fellow in Botany, as senior author. Other publications in connection with the 

 work on shade tree diseases during the year include: "Combat the Elm Disease" 

 and "Diseases of Nursery Plants" in American Nurseryman; "W'illow Scab" 

 (mimeographed); "Repair of Hurricane Damaged Trees," Extension Circular; 

 and "Dealing with Storm Damage in Central Massachusetts" in Proceedings 

 Eastern Shade Tree Conference, New York Botanic Gardens, December 8-9, 1938. 



The serious damage to trees during the hurricane of September 21, at which 

 time approximately 100,000,000 trees were destroyed in Massachusetts, created 

 multitudinous problems in shade tree management throughout widespread areas 

 of the State. Evergreens, especially white pines, near the coast were seriously 

 injured both by flooding caused by the abnormally high tides and by salt spray. 

 Weather conditions of the past summer were favorable for a disease known as 

 "needle-blight" of white pines, and the discoloring effect of salt carried by the 



