« AnteriorContinuar »
ground, the scales are formed at longer intervals, and there are correspondingly fewer places for the production of tuber-bearing branches. Also, in the latter
FIG. 12-POTATO PLANTED FOUR INCHES DEEP
(Diagrammatic) a-Ground level. 6-Seed potato. (-Short sprout sent up before planting, which sent up two branches, d, e; d being broken off, and e cut off at f. g--The tuber-bearing stem, or rhizome, which bears buds at h, and thickens at the end to form a tuber, i, upon which eyes having buds, k, may be seen. m is a tuber-bearing branch, or rhizome, which has not yet begun to form a tuber, and r shows where the roots were broken off. Generally four roots
are sent out for each tuber-bearing branch.
case, the leaf-bearing branches produced above ground are weaker. The system is considered essential in the island of Jersey and the early potato growing districts of the United Kingdom, and is practiced to a small extent for the second crop in the Southern States.
FIG. 13-POTATOES SPROUTED PROPER LENGTH FOR THE PLANTER Starting the growth of the tubers in this way is profitable in many places.
By sprouting the seed tubers, the Kansas Experiment Station' have planted potatoes in March and lifted the crop on June 1. At the Rhode Island Experiment Station' potatoes were held in a fairly well-lighted room at a temperature of 60° to 75° F. for four to six weeks.
FIG. 15—SPROUTS TOO LONG AND WEAR This often occurs when potatoes are left in sacks, barrels, or in piles in the cellar. As soon as sprouting begins, spread the tubers thinly on the barn
floor, in the light, to check this waste of energy.
In this time thick buds, one-half to an inch long and one-quarter to three-eighths of an inch in diameter, formed (Fig. 14). The potatoes may be held at this stage for some weeks if necessary by lowering the temperature. Early Rose potatoes weighing about three ounces each were sprouted as described, and planted on May i beside siinilar tubers which were unsprouted.
1 Kan. Bul. 70, p. 149, and Press Bul., March 6, 1899. ?R. I. Bul. 36, pp. 9-19.
Part of the crop was harvested July 29, the yield being decidedly in favor of the sprouted seed, which lead was maintained (see Table).
TABLE IV YIELD PER ACRE FROM SEED TUBERS SPROUTED AND NOT
In trials made at Cornell Station by the writer during 1904, with the varieties Sir Walter Raleigh and Carman No. 3, increased yields of from 0.9 per cent. to 73.7 per cent. resulted from sprouting potatoes in the light for 36 days previous to planting, when compared with holding them in a root-cellar to the time of planting. The sprouts on the tubers held in the cellar were up to three inches long; those held in the light were but one-half to three-quarters of an inch long. No misses occurred, except from those sets held in the cellar. It seems probable that each variety may have its own optimum temperature, as conditions were uniform for both varieties. Eighteen hills were used in a plat, and Table V., on page 59, shows the results.
Another great advantage in sprouting is that it gives an opportunity to note variation and “rogue" the variety. Almost every variety shows a difference in the sprout, either in color or habit of growth; one
may have a white, spivdly stem, which becomes green on exposure; another a short, sturdy stem, which becomes bright red; while another may be purple, and so on. So far I have found the “sprouting stage” the most reliable one at which to note differences in varieties, and varieties of potatoes may be distinguished as readily as varieties of other crops.
The disadvantage of the system of sprouting potatoes is that the tubers must be planted by hand on account of the liability of knocking the sprouts off if passed through the planter. There are many local markets in the United States poorly supplied with early potatoes, and to supply such a small area of the crop could be profitably handled as above described. A distinction must be noted between the above method