THINNING

The thinning of potatoes grown under irrigation has not been practised with any degree of success where tried in Nevada. The object of thinning is to remove the less thrifty stems and to establish unifor

Fig. 14-Another Type of Sulky Potato Digger used in Harvesting
Nevada Potatoes.

mity in the number of stems per hill. The Montana Station conducted experiments in 1913 and 1914 on the thinning of potatoes, and, with the Burbank variety planted 12 inches apart in the rows, the yield of marketable potatoes was over 20 per cent higher for the unthinned potatoes than for those which were thinned.

FLB

Fig. 15-A Simple Type of Hand Potato Sorter.

The thinning of potatoes is not to be recommended for Nevada growers, and where seed pieces are used with not more than two or three

good strong eyes, little trouble is encountered in producing too many stems to the hill.

SORTING FOR MARKET

The demand for a more uniform potato that is free from disease and blemishes has caused a number of Nevada growers to sort or grade their potato crop before marketing. For small lots an ordinary hand sorter is very effective. This consists simply in an inclined table with slats to allow the dirt to fall through, and with the lower side open so that the market potatoes can pass into the attached sack. This is not a very long or difficult process, and it adds greatly to the market value and keeping quality of the potato. The culls may be used on the farm as a succulent feed for dairy cattle or hogs.

Fig 16-A Potato Sorter showing Sack
Attachment for Market Potatoes.

The standard market grades as now established in the United States

are as follows:

No. 1-Potatoes over 1% inches in diameter for the round varie

ties and 134 inches in diameter for the long varieties. Less than 5 per cent shall be undersized, and an additional 3 per cent is allowed for injured potatoes.

No. 2-Potatoes over 11⁄2 inches in diameter and not more than 5 per cent undersized. An additional 5 per cent is allowed for injured potatoes.

Fig. 17-A Home-made Sled Potato Sorter used in the Truckee Valley. One man with this Machine follows five pickers in sorting and sacking the potatoes ready for market.

STORING

On account of the severe winters, which occur in Nevada from time to time, growers should provide storage facilities for their crops that the tubers may not be injured by freezing or heating. Both the cellar and the ordinary field pit may be used successfully for this purpose. In Bulletin 79 of the Idaho Experiment Station, the following information is given concerning potato cellars, which is very applicable to Nevada conditions:

In a dry well-drained location a pit four feet deep and any width and length to accommodate the needs should be dug. A knoll is preferable to a side hill. It may be stated that a cubic foot will store approximately forty pounds. The studding for side walls may be posts set firmly in the ground and should rise a foot above the surface of the ground. The roof need not have greater than one-fourth

pitch. It may be built of round poles or 4x4-inch timbers for the rafters and covered with stock lumber. Ventilators 10x10 inches are necessary every sixteen feet in the ridge. The whole structure is now ready for the final covering, and it may be started with eighteen inches of straw and then six to eight inches of the soil which was removed from the pit.

Where large amounts are to be stored the cellar should be wide enough to permit of a driveway. There need not be a door at each end, although that is better. Where the crop is stored in sacks a floor is necessary, as sacks will rot if put in contact with the soil. This floor may be slatted, as this will facilitate ventilation.

The temperature for best results should be but two or three degrees above the freezing-point, 34°F. being ideal. This temperature should be maintained as nearly as possible. With some attention this is simple. Where the nights of spring and fall are cool, as in almost all parts of the State, the opening of doors in the evening and closing early in the morning after the crop is put in will soon reduce the temperature to the standard. It can be maintained quite closely by the judicious use of the doors throughout the storage season.

Fig. 19-A Potato Pit used in storing a large portion of the
Nevada Potato Crop.

Much of the Nevada potato crop is stored in field pits, which are located on high land in the field where good drainage is possible. The bulletin on Nevada Potatoes, by C. A. Norcross, describes in detail the storing of potatoes in pits as follows:

Having chosen a site for a pit, scrape off about six inches of the top soil, and form a ridge about the base of the proposed pit, which should be about four and one-half or five feet wide by sixteen or twenty feet long. Tramp the bed so it is as hard and firm as possible and smooth it. The potatoes are poured into this open pit on the dirt and piled to a triangle point or ridge, the length of the pit. When so piled, cover the potatoes with dry potato vines or straw so that when compressed the mat will be three or four inches in thickness. Over this layer of vines or straw throw a six-inch layer of dry dirt, leaving two or three openings at the top of the pit for the escape of heat and moisture. Pat the outside of the dirt covering with the back of a shovel until it is firm and smooth so that rain will run off rather than percolate.

Next, dig a drain around the pit and leading away from it, and the first stage of the pit is completed. After a week or so close the openings left for

ventilation. Before freezing weather commences in earnest add a foot or more of soil to the pit covering, pat it down, and see that the drainage ditches are open. The depth of the final soil-covering varies in different sections, and the experience of local farmers is the best criterion.

Pits should be located north and south, rather than east and west, in order to render uniform the sunshine on both slopes. When placed east and west the north slope is usually damper than the other and is slower to thaw in the spring. The sunshine, while it warms the sides, also evaporates the moisture, rendering a north-and-south pit drier than one that is east and west.

For further information on potato culture, address

DEPARTMENT OF AGRONOMY,

University of Nevada,
RENO, NEVADA.