STORAGE OF TRUCK CROPS: THE GIRASOLE, HELIANTHUS TUBEROSUS

The girasole,3 Hetianthus tuberosus, has had much interest centered upon it since the report of JACKSON, SILSBEE and PROFFITT (4) on the possible commercial preparation from it of fructose, a sugar sweeter than sucrose, according to PAUL (7), DEERR (3), SALE and SKINNER (8), BIESTER, WOOD and WAHLIN (2) and SPENGLER and TRAEGEL (10). A survey of the plants which might serve as a source for the commercial production of fructose shows that the girasole ranks among the more promising. The plant has been in general use in many European countries for a long time as a truck crop and as a stock food, and to a lesser extent this is true for certain sections of the United States. One of the chief problems in connection with this crop is that of storage. The periderm of the girasole tuber is very thin and easily ruptured. There is a rapid loss of moisture on exposure to atmosphere at room temperature. The tubers are subject to parasitic diseases under ordinary storage conditions.4 Most authorities seem to be agreed that the best method of storage is the practice of leaving the tubers in the ground and digging them when needed. SHOEMAKER (9) reports good success with tubers stored in burlap bags in a cold cellar at Washington, D. C., from November, 1925, to March, 1926, without shriveling or other difficulty. The temperature was kept near the freezing point. The preliminary experiments reported in this paper covering the period from August 30, 1927, to March 22, 1928, were carried out in order to secure more accurate information with regard to the storage of this crop.