98 MASS. EXPERIMENT STATION BULLETIN 355 



PUBLICATIONS 

 Bulletins V 



347 Annual Report for the Fiscal Year Ending November 30, 1937. 99 pp. 

 March 1938. 



The main purpose of this report is to provide an opportunity for pre- 

 senting in published form, recent results from experimentation in fields 

 or on projects where progress has not been such as to justify the general 

 and definite conclusions necessary to meet the requirements of bulletin 

 or journal. 



348 Control of the Begonia Leaf-Blight Nematode. By E. F. Cuba and C. J. 

 Gilgut. 12 pp. March 1938. 



The culture of Lady Mac, Melior, and Marjorie Gibbs begonias rep- 

 resents a large enterprise in many floriculture establishments in Massachu- 

 setts. The leaf-infesting nematode is often a serious menace to the suc- 

 cessful culture of these begonias. Sanitary and cultural methods within 

 the limits of good plant growth and commercial practice are not effective 

 in arresting the progress of the disease. Propagating from stock free of the 

 leaf-blight nematode disease is the best measure of control. A method 

 has been worked out for treating begonia plants by submersion in hot 

 water, which has proved satisfactory in killing the nematodes. Besides 

 a report of the experimental results, this bulletin contains detailed direc- 

 tions for using the hot-water treatment on a commercial scale. 



349 Shade Tree Law in Massachu.«etts. B\- Edward T. Simoneau. 19 pp. 



February 1938. 



The value of shade trees is recognized in Massachusetts, as is evidenced 

 by the numerous laws enacted relative to their care. This bulletin sets 

 forth the legislative history of the laws relating to shade trees, with a 

 more detailed discussion of the present shade tree statutes and court 

 decisions rendered. It is particularly useful to tree wardens and others 

 who may be charged with the care and oversight of public shade trees in 

 Massachusetts. 



350 Tomato Leaf Mold as Influenced by Environment. B\- E. F. Cuba. 24 pp. 

 May 1938. 



This bulletin deals with the various environmental factors which in- 

 fluence the development of the tomato leaf mold fungus and the infection 

 of the tomato plant in the greenhouse, together with a comprehensive 

 review of the pertinent literature. The disease is epidemic during the 

 warmer months from June to October inclusive, when maximum greenhouse 

 temperatures of 80° to 92° F. prevail; when the mean minimum inside 

 and outside temperatures converge to narrow difference of less than 5° F.; 

 and when the highest mean maximum relative humidity of 94-100 per- 

 cent for the year prevails. The severity of the disease is related funda- 

 mentally to temperature. 



351 Germination of Seeds and Damping-ofi" and Growth of Seedlings of Orn- 

 amental Plants as Affected by Soil Treatments. By William L. Doran. 

 44 pp. May 1938. 



Damping-ofT is a major problem in the propagation of plants from seed. 

 It is not altogether controllable in practice by regulating and adjusting 

 the environment (soil moisture, temperature, and reaction), for conditions 

 favorable for the fungi are too nearly the same as those preferred by the 

 plants. In washed sand or in a combination of sand and sphagnum or 

 peat moss, there was very little damping-off as compared with that in 

 soil. However, growth was always poorer in sand, even with fertilizer 

 added, than in soil. Hence the search for better, safer, and less expensive 

 soil disinfectants continues. This bulletin presents a summary of studies 

 involving the use of a large number of chemicals and 112 species of orna- 

 mental plants. 



352 The Carrot Rust Fly. By VV. D. Whitcomb. 36 pp. May 1938. 



This is a report on the history and distribution; host plants: injury 



