This section is from the book "The Potato: A Compilation of Information from Every Available Source", by Eugene H. Grubb, W. S. Guilford. Also available from Amazon: The Potato: A Compilation Of Information From Every Available Source.
The early potato, like all other early vegetables and fruit, is an "out of season" or "semi-out of season" product, and consequently brings a fancy price.
Extraordinary conditions, either natural or artificial, are required for its production.
The early potato is a specialty suited to the colder part of the season in semitropical countries, such as California, Mexico, Florida, and Texas.
Protection from early frosts is a prime consideration in sections where the climate is other than strictly semitropical. There are great possibilities for the industry in the Sacramento Valley and other sections of California.
One great advantage of an early crop is that it is matured and harvested before the time (August and September) when the blights and other diseases may ruin the late crops.
Some work has been done by American experiment stations in investigating the business. In "Farmers' Bulletin 114" of the United States Department of Agriculture is the following: "A difference of two or three days or a week in the placing of a crop on the market often makes a difference between profit and loss, and the prices obtained for extra-early crops have stimulated cultural experiments with every kind of fruit and vegetables. Some interesting results along this line. with potatoes have recently been reported by the Kansas and Rhode Island stations.
At the Kansas station seed tubers of four different varieties of medium-sized potatoes were placed in shallow boxes with the seed ends up in February. They were packed in sand, leaving the upper fourth of the tubers exposed, and the boxes were placed in a room with rather subdued light, having a temperature of 50 degrees to 60 degrees F. Vigorous sprouts soon pushed from the exposed eyes. The whole potatoes were planted in furrows in March in the same position they occupied in the boxes. The same varieties of potatoes taken from a storage cellar were planted in parallel rows. The sand-sprouted potatoes took the lead from the start in vigor and strength of top and produced potatoes the first of June, a week earlier than the storage-cellar potatoes. At the final digging they showed better potatoes and gave a 10 per cent. larger total yield.
In another experiment part of the potatoes was treated the same as in the first test, except that the sand was kept moistened and the other part was placed in open boxes and kept in a light room having a temperature of 50 degrees F. The tubers placed in sand developed strong sprouts and nearly all rooted. When planted in the field they outstripped both the tubers sprouted in open boxes and the storage-cellar tubers in vigor of growth. The tubers started in the open boxes gave earlier yields than were obtained from the storage-cellar tubers, but not as early as the tubers sprouted in moist sand. The tubers sprouted in moist sand produced table potatoes from seven to ten days earlier than the storage-cellar seed.
At the Rhode Island station medium-sized whole potatoes sprouted on racks, in a fairly warm and light room, gave a 27 per cent. better yield at the first digging than potatoes kept in a cold cellar until planting time, and this was increased to 40 per cent. at the final digging. The percentage of large tubers was also greater at each digging with the sprouted tubers.
The results of these experiments are suggestive. The handling of seed potatoes in such manner as to secure strong, stocky sprouts before the tubers are planted out is shown to be an important factor in increasing both the earliness and the total yield of the crop. By planting only well-sprouted seed a full stand is assured.
One of the objections to this method of growing potatoes is the large amount of space required for exposing the tubers to the light for sprouting. This objection has been overcome in part by the use of trays and racks. At the Rhode Island station the rack used held nine trays. Each tray was three and three fourths feet long and one and one half feet wide, and would hold about one bushel of potatoes when spread out in a single layer for sprouting. The bottoms of the trays were made of pieces of lath placed about one inch apart. Nine trays were placed in a rack over each other, leaving about nine inches of space between each tray. This method of arrangement has the advantage of securing a very uniform distribution of light, heat, and air for all the trays. It greatly facilitates the handling of the potatoes and lessens the danger of breaking off the sprouts when transferring to the field for planting."
E. L. Cleveland, Houlton, Maine.
Where it is desired to grow potatoes on heavy lands or without cultivation they are sometimes planted under straw.
In a Nebraska Experiment Station publication R. A. Emerson says:
Potatoes are a cool weather crop. It is because of this that they succeed so well in the far north. Moreover, potatoes require for their best development fairly uniform conditions, especially as regards soil moisture and soil temperature. This being the case, why should not potatoes grown under a litter mulch be especially well developed and therefore make strong seed? The soil beneath a mulch not only has a moderately low temperature during summer, but its temperature is also exceptionally uniform, varying not more than a degree or two between day and night and only a few degrees from day to day. The soil moisture beneath a good mulch is also more abundant and much more nearly uniform in amount than in case of bare ground, even though the latter is given good tillage.