Varietal purity.—­Commercial potato shipments should be graded to one variety.

All indications show that Minnesota must grade and sort for commercial shipments of potatoes, and that a definite brand or grade designating a definite standard must be adopted in order to secure the highest prices.  All inferior stock must be thrown out, and the best potatoes given a chance to make an attractive showing.

The standing which Minnesota potatoes will have in the market will be determined a great deal by the grading, which is usually the work of the dealer, although some farmers do their own grading by hand.  Ungraded potatoes injure the Minnesota potato trade and reduce the profits, as the freight is the same on dirt, small and unsound potatoes as it is on the fine stock.  As much as a ton of dirt and culls is sometimes found in a car on the Chicago “team tracks” after the wholesale merchant has sacked all he is willing to accept.  This freight, sorting charges and cost of disposing of refuse must be paid by some one.  Co-operating to improve the sorting done at loading stations is a means of establishing a grade to meet competition and to reach new markets.

[Illustration:  Figure IV.  Early Ohio.]

Standardization also means grading to eliminate potatoes infected with disease, such as common scab and late blight, sunken discolorations or dry hard blisters, green, spongy and coarse stock.  All of these defects tend to lower prices.

In order to increase the value of the Minnesota potato we must also supply the market with the variety which it demands, and, furthermore, this variety must be free from mixture.  Minnesota has already taken a step in this direction.  The Minnesota Agricultural Experiment Station, Minnesota Crop Improvement Association and the Minnesota Potato Growers’ Association have recommended the following varieties and types to be selected and grown.

The Rural New Yorker, as shown in Figure 1, is the leading round, white, late potato for Minnesota.  It is a good yielding and keeping variety, fine in quality, an excellent market sort and suitable for almost any soil.

Similar to the Rural New Yorker are the Carman No. 3 and Sir Walter Raleigh.

The Green Mountain is a desirable white late potato, similar to the Rural New Yorker, but more oblong and with squarer ends.  It is better suited to rich heavy soils than the Rural New Yorker, as they are not so likely to grow hollow.

[Illustration:  Figure V. Triumph.]

Other similar varieties are the Carman No. 1, Green Mountain, Jr., and
State of Maine.

The Burbank (Fig.  II) is a long, white, late potato of excellent quality and suitable only for rich, loose, loam soils.  Thrives well upon new rich soils that are well supplied with humus.

Other inferior varieties confused with the Burbank are the White Chief,
White Star and Pingree.