1068 EXPERIMENT STATION RECORD. 



standpoint of space, therefore, the returns per square foot were 26 cts. from flat- 

 grown plants and but 10 cts. from bench-grown plants. 



The conclusion is drawn that for local market conditions a greater net profit can be 

 made from lettuce planted in flats. The growing of the plants in flats to maturity 

 considerably lessens the labor required, though the lettuce is not so heavy nor so 

 good by close planting as when sufficient space is allowed for development. 



In the combination indoor and outdoor lettuce culture, lettuce was started in the 

 greenhouse and transplanted to the open as soon as weather conditions permitted. 

 Good crops were thus secured. The average weight of the plants of a number of 

 different varieties grown for 2 years is tabulated. Iceberg gave the heaviest yield in 

 each of the 2 years. It is believed that seedlings could be grown equally as well in 

 the hotbed as in the greenhouse for this work, and that in the vicinity of the station 

 this method of culture would be very profitable. 



Fertilizer experiments in field culture of garden peas (Maine Sta. Bid. 126, 

 pp. 30-34). — Garden peas were grown for a cannery on 2 farms. Part of the peas 

 grown was inoculated with pure cultures of nitrogen-fixing bacteria from the Depart- 

 ment of Agriculture and from commercial sources. Commercial fertilizer was used 

 on both farms. A severe drought seriously interfered with the experiment. 



On one farm the soil was found to be thoroughly inoculated with the nitrogen- 

 collecting bacteria, and the use of pure cultures was without additional benefit. On 

 the other farm which, so far as known had never been planted to peas, some of the 

 plants on the inoculated plats were found to contain tubercles on the roots, but no 

 more than on some of the other plants which were not inoculated. 



The cassaba melon (Pacific Rural Press, 71 (1906), No. 10, p. 148).— The history 

 of this muskmelon, also known as Winter Pineapple Muskmelon, is given, with an 

 account of its introduction into the United States, and the methods observed by the 

 author in its culture. This is a late melon, suitable for Christmas use, and grown to 

 some extent as a stock food. 



Report of culture experiments in 1905 on the sewage fields of Berlin, 

 J. Klar and O. Mende (Gartenjiora, 55 (1906), Nos. 2, pp. 35-40; 3, pp. 66-70).— 

 The results are given of tests in growing large numbers of flowers and vegetables, 

 with brief comments on the various varieties. 



Soil sterilization, W. Stuart ( Vermont Sta. Rpt. 1905, pp. 297-299).— A historical 

 account is given of the development of soil sterilization by means of steam and other- 

 wise in this country, with an account of the author's investigations in sterilizing soil 

 in solid beds and subwatered benches. 



" Three in. drain tiles were sunk about 10 in. below the surface of the soil. The 

 lines of tile were laid every 16 in., each line being independent of the other and 

 connected with the surface by a vertical section of draintile." When steam was 

 properly connected and turned in the tile at a pressure of 40 to 60 lbs., a bed con- 

 taining approximately 70 sq. ft. of surface could be heated up to about 210° F. in 

 about 3 hours' time. When the surface soil was well covered with burlap, the heat 

 was maintained at this temperature for a long time, and was entirely effective against 

 nematodes. This method of soil sterilization involves less labor than the usual 

 method of sterilizing in boxes, as there is no handling of soil and the draintiles are 

 far enough below the surface to be out of the way of cultural operations. 



A large portion of the bench surface in the greenhouse is fitted for subwatering by 

 means of galvanized iron pans and layers of porous brick. An attempt was made to 

 sterilize the soil in this bench by injecting steam into the pan through the watering 

 tube. The result was unsatisfactory, as too much steam was required. Much of the 

 steam condensed in coming in contact with the cold porous bricks, and it is believed 

 that it would be more economical to employ a sterilization box in the treatment of 

 soil in subwatered benches. 



