ANNUAL REPORT, 1931 243 



For reports on experiments conducted at this Station, in addition to those 

 listed under this caption, see report of the Departments of Botany, Entomology 

 and Floriculture. 



The Plant House. (P. \\'. Dempsey). Interest on the part of growers in 

 this superior method for growing plants continues. A new set of plans including 

 some improvements over the original plant house has been mimeographed, for 

 the purpose of mailing in response to definite requests. Since this project was 

 started in 1928, some 2000 copies of plans and specifications have been dis- 

 tributed throughout New England, and many visitors have come to the P'ield 

 Station with the sole idea of looking over the model plant house which has been 

 erected here. 



Electricity as a Source of Heat in the Hotbed and Propagating Bench. 



(P. W. Dempsey). Three hotbeds of four sash each were operated in the early 

 spring to determine the comparative merits of manure, hot water and electricity 

 as sources of heat. Considering both the cost and the results obtained, electricity 

 at 5 cents or less per kilowatt hour is entirely practical for the grower using less 

 than fifteen sash. The commercial production at a fair price of a practical lead- 

 covered, almost foolproof, heating cable and a reliable thermostat makes this 

 new method of heating hotbeds available to the grower. Work will be continued 

 to gain more essential knowledge along this line. A mimeographed set of plans 

 and specifications was made in the late spring and over 200 copies have been 

 distributed in response to requests for information. 



The same equipment, cable and thermostat can be used as a source of bottom 

 heat in the propagating bench and elsewhere in the greenhouse. Last winter 

 considerable work was done using strip heaters, coiled resistance wire, and other 

 heating elements, but all of these became decidedly antiquated upon the intro- 

 duction of the leafl-covered cable in February of this year. At present, December, 

 1931, there are being maintained five different temperatures under carnations, 

 four different temperatures in the propagating bench, and a heating cable under 

 two rows of cucumbers providing a differential af 10° F. 



Most of this work is done in cooperation with the Edison Electric Illuminat- 

 ing Company of Boston and the General Electric Company. 



Vegetable Variety Trials. (P. W. Dempsey). Forty varieties and strains 

 of lettuce were planted at various times during the season. The so-called "White 

 Big Boston" variety continued to show outstanding qualities that make it worthy 

 of trial by lettuce growers. For three years unsatisfactory results have been 

 obtained from many strains of the Black Seeded Tennis Ball type. From similar 

 reports made by growers it would seem that this variety may be going to pieces. 

 We have been recomn^ending it for years as the standard head lettuce variety. 

 Next year we are planning a thorough study of the Black Seeded Tennis Ball 

 and White Big Boston varieties. 



Fifty-two strains and varieties of sweet corn were planted at two different 

 dates. Spanish Gold, a new introduction from Dr. Jones of Connecticut, showed 

 up exceptionally well as a high yielding early yellow corn. Golden Gem as the 

 earliest yellow corn of fair size and good quality, and Golden Sunshine as a 

 standard variety to replace Golden Bantam continued to show great promise 

 for the future. 



Forty strains and varieties of beets were seeded in two plantings. The var- 

 iety names Crosby Egyptian and Early Wonder are practically synonymous. 



