American Journal of Horticulture 5: 28-30 (1869)

UNPRECEDENTED PROPAGATION OF THE EARLY ROSE POTATO
W. C. Strong
BRIGHTON, MASS, December, 1868.

THE high price of the Early Rose Potato, and the strong commendation of its qualities, induced me to purchase of B. K. Bliss & Son six pounds in March, 1868. Potatoes at a dollar per pound will warrant propagation under glass. I ordered the tubers to be cut into single eyes, and to be planted in a box in the propagating-house. As soon as the eyes had made a growth of two inches, they were taken off precisely as dahlia-cuttings are taken, or like the cuttings of verbenas, which may be a more familiar example to many. This process commenced about April 20. After the first batch of cuttings was taken, a new set of shoots developed from the tubers; and, in some cases, three or four shoots were obtained before the tubers were potted from the box. As these tubers were put in thumb-pots, and, during the pressure of spring nursery-work, were kept too long in this confined space, though they were planted in open ground about the 20th of May, yet it was too late for them. Concluding that the pot was to be their limit of growth, they had determined their course,— to ripen up their new and beautiful little tubers about the size of a Miniť-ball, and then retire from the field. Consequently, I got no potatoes of any size directly from the original six pounds of tubers. But to return to the cuttings. As stated, the first batch was obtained about April 20. These were placed in the sand-bed of my propagating-house, having a bottom-heat of about 75° Fahrenheit. The temperature of the house was kept about 10° lower; and, as the face if the roof is toward the north, there was little trouble with the light and heat of the sun throughout the month of May. The cuttings rooted with great certainty in six to eight days, and were at once removed to thumb-pots. For another week they were kept in frames, until the roots were well out, so as to hold the earth as a ball when turned from the pot. They were then planted in drills in the open field, three feet apart, and one foot in the drill. As fast as these plants made shoots which could be taken without serious loss to the parent-plant, they were removed, and placed in the propagating-bed, as before. Thus the process was repeated as late even as to the 5th of August. At first, it was from a small beginning, and, of course, a slow progress. But, as the case came under the rule of geometrical progression, on the 20th of July we reached the limit of capacity of our propagating-bed, which was fifteen thousand potato-cuttings; the leaves being large, and requiring space. The total number of rooted plants was about seventy thousand from the six pounds of tubers. During the unusually warm weather of June and July, it was somewhat difficult to sustain the soft, succulent growth. The cuttings flagged and wilted. It was necessary to shower the bed, and keep the house close, preventing any exhausting draught of air. Still the slight heat from the water-pipes required to keep up the bottom-heat made the temperature of the house excessive at times. We resorted to mats on the roof as a shade. In spite of all efforts, from ten to twenty per cent of the cuttings would damp off during the warm season.

The cost of this process can easily be estimated. Three men can prepare and put into the bed about eight thousand cuttings per day. They can pot from the bed about half that number. And again: they can plant in the field about four thousand. In other words, a day's work of one man will make the cuttings and pot and plant in the open field about five hundred and thirty-three plants.

And now for the results.

The early plants exceeded my most sanguine expectations; becoming established at once, and developing tubers surprisingly. It required but forty days for a potato-top of two inches in length to root and develop and mature two or three large-sized tubers. On account of the continued process of taking cuttings, none of my plants had a full trial. The actual yield of those planted up to July 30 was at the rate of a hundred and sixty bushels per acre, of full size. But very much the largest part of my crop was planted after Aug. 1, not with any expectation of obtaining large seed, yet with confidence that small and healthy seed-tubers would be the result. In this I have not been disappointed. Indeed, the result would have much surpassed my expectation, had not the season proved extraordinarily cold and wet during the months of September and October. About the middle of September, a cold north-east rain prevailed, and a sudden change came over every potato-field. All kinds rotted more or less, many fields being not worth digging. My crop, being late, was in just the most susceptible state, and it suffered severely. A large quantity could not be picked up and measured. Of those which were gathered we had eighty bushels of large and sound tubers, besides several bushels of sound late-planted seed, varying from the size of a Miniť-ball up to an English walnut. It is not fair to reckon these by measure; for a bushel will count by thousands. It was a disappointment that an experiment for the largest increase of a crop from a given amount of seed should be disturbed by disease. Still I am inclined to believe the present result is unprecedented; being nearly ten times larger than the hundred-fold of Scripture.

For the sake of comparison, I tried cuttings of Goodrich's Early Potato. Greatly to my surprise, they did not root readily; neither did they develop with any thing like the rapidity of the Rose. The trial was with but one batch, and with only fifty cuttings, half of which failed for some reason. With so narrow a limit of experiment, I cannot speak positively; yet it would seem probable that the Rose is peculiar in the readiness to form tubers. Any one who has had many plants must have noticed bulblets forming on the vines above ground. Certainly it indicates marked productiveness as well as earliness, and excellency in quality. I do not regard my example as any indication of its liability to rot, though this may be true of it. Certainly a variety so early and so tender should not be exposed to the cold storms of autumn, especially in a growing state. The sound tubers which were rescued show no disposition whatever to rot. It is a fair question for consideration, whether this method of propagating the potato can be put to practical use in other cases than the increase of new and high-priced varieties. Upon this question I leave others to speculate: but, upon a correlative question, I will express an opinion; to wit, that the tubers produced from cuttings are as perfect, sound, and vigorous as can be obtained either from seed or from the old tuber.

[The unprecedented success of Mr. Strong in the propagation of the Early Rose Potato last season has brought so many inquiries from all quarters, that we have induced Mr. Strong to send us a full and accurate account of his operations, which we are happy to give our readers.]