Harvesting, threshing and storing.
The sunflower heads should be harvested before the seeds are fully ripe. As soon as the seeds are ripe they begin to shatter, and before the crop is mature it is likely to be damaged by birds which gather in flocks to feast on the rich seeds. As ordinarily gathered the seeds will not be dry enough to shell and store, but the heads should be cured for a week or so before threshing or shell ing. If only a small quantity is grown the heads may be spread out on the barn floor or in a loft or shed. At the Kansas Experiment Station has been followed the plan of cutting off the heads with a sickle or corn knife and putting them in shallow windrows in the field for several days, when they are hauled in and threshed or stored in large piles. More or less loss attends the handling of the crop in this way.
There seems to be no satisfactory or economical method of threshing out the seed. Often the seeds are shelled out by hand, or they may be pounded out with a flail. Some farmers construct a wooden disk or wheel arrangement, hung and operated in the same way as the ordinary grindstone. The sides of the disk are driven very full of nails, against which the sunflower heads are held as the disk revolves, thus removing the seeds quickly. These methods are slow and cumbersome. Although the writer has not seen it tried, it seems probable that when the heads are fully dried the seeds may be threshed out by the ordinary grain separator. At least some cheap and more rapid method must be found for harvesting and handling the crop be fore it can be grown successfully in a large way.
If the seed is fully dry when it is threshed it may be stored safely in large bins, but if the heads are yet green and the seeds not fully dry when threshed, the seed must be spread out and dried before storing in large quantities. Often the seed may be stored safely in sacks, barrels or small bins before fully dry. Fermentation must be avoided, otherwise the quality of the oil will be lowered.
Yield.
By the 'worts of farmers who have grown the crop, an average yield appears to be 1,000 to 1,500 pounds of seed per acre. W. S. Dean reports a yield on his farm of 2,250 pounds of seed per acre in 1891, while other growers report yields as low as 600 pounds per acre. The yields
of green matter per acre is four to five tons. The average weight of a bushel of seed is about thirty pounds.
Uses.
Feeding.—No experiments in feeding sunflower seed to stock have been published by any of our experiment stations. Some experiments were made several years ago in Maine, Vermont, and at some of the Canadian experiment farms. in ensiling sun flower heads in combination with other crops, and feeding the silage, but, on the whole, the results of these experiments seem to have been unsatisfac tory. By the reports received, so far as sunflower seed has been fed by farmers in this country the results have been satisfactory. The whole seed ground and fed with other grains makes a rich and palatable food for growing and fattening stock. If sunflower seed can be produced in suffi cient quantity and cheaply enough, it should be come a valuable feed for stock in this country. In Russia, the stalks of the plant are ground up and fed as roughage to horses, cattle and sheep.
In the manufacture of sunflower oil, " oil-cake " is left as a by-product, and meal made from the oil cake makes an excellent food for stock. The cake is rich in protein and oil and is well relished by stock.
Robertson mixture.—The Robertson mixture is a combination of corn, sunflower heads and broad beans in the form of silage, in the proportion of one-half acre of sunflower heads to two acres of broad beans and corn. The corn and beans are harvested when the corn in the ear is beginning to glaze. Fifty pounds of this mixture may take the place of the corn silage in the ration, using about four pounds less grain than ordinarily goes with the corn silage. [See Bean, Broad, p. 212.] Oil.—The small-seeded variety is preferred for the manufacture of oil. When cold-pressed, a yel low, sweet oil is secured that is considered equal to olive or almond oil for table use. If this resi due or "oil-cake" is warm-pressed it yields an oil that is useful for lighting purposes, and for wool len-dressing, candle- and soap-making. The per centage of oil ranges from 15 to 28.