176 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



grapefruit apparently decreases during storage, as the fruit seems 

 considerably sweeter after a period in storage. 



SWEET-POTATO INVESTIGATIONS. 



The importance of the sweet potato has increased very miiterially 

 during the past few years. The curing and storage work has been 

 conducted principally at Arlington Farm, Va., and at the Peedee sub- 

 station of the Soutli Carolina Agricultural Experiment Station at 

 Florence, S. C, the latter work being cooperative. A general sum- 

 mary of the curing and storage Avork is expressed in the statement that 

 where the potatoes are carefully handled during the harvest and cured 

 in a storage house of the design recommended by this department for 

 a period of ten days to two weeks at a temperature of about 90° with 

 plenty of ventilation, followed by storage in an approved storage 

 house at a temperature of 52° to 56° F. with occasional ventilation, 

 practicall}^ all varieties can be kept through the winter with a loss 

 from deca}' on an average of not to exceed 1 per cent. 



With the development of a Satsuma orange industry in certain 

 areas of the Gulf coast region and the probability of the construc- 

 tion of houses for use in fruit curing, some attention has also been 

 given to the iDossibilities of making a dual-purpose house, not only 

 for the Satsuma orange w^ork but for sweet-potato storage. It is 

 believed that there are no difficulties existing with respect to utiliz- 

 ing the same structure for the successful handling of both of these 

 crops. It has also been shown that the tjq^e of tobacco-curing house 

 used in some sections can be adapted readily to the needs of sweet- 

 potato curing and storage. 



VEGETABLE FORCING. 



The studies of the forcing of vegetables have been confined pri- 

 marily to cucumbers, tomatoes, lettuce, and cauliflower. Planting 

 distances and other cultural problems have been investigated; also 

 the results of seed selection, particularly in the latter case with 

 cauliflowers. It has been shown that plants from carefully selected 

 seeds yielded about 90 per cent of marketable heads, as compared 

 with about 50 per cent of marketable heads from plants grown from 

 unselected seeds. 



IRISH POTATO PRODUCTION INVESTIGATIONS. 



The Irish potato investigations were considerably extended the 

 past year, the extension being mainly along two lines, namely, 

 seed-potato development and the testing of northern-grown certi- 

 fied seed or inspected Triumph seed in the South. In carrying for- 

 ward the seed-potato development work, cooperative arrangements 

 have been made by this bureau Avith a number of experiment stations, 

 including those in Oregon, Minnesota, Wisconsin, Louisiana, Texas, 

 Oklahoma, and Arkansas, the cooperative work with the four stations 

 last mentioned involving particularly the testing of northern-grown 

 seed in southern potato-growing regions. 



In testing the high-grade northern-grown seed potatoes at south- 

 ern points the fact was A^ery markedly brought out that the different 

 lots of inspected or certified seed when groAvn under similar condi- 



