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THE POTATO ITSELF-WHO WILL IMPROVE IT FURTHER?

NO PLANT IS EVER A FINISHED PRODUCT-POTATO SUGGESTIONS

The story of the Burbank potato has been told many times. But it has seldom been told correctly. Like stories in general, it gains or loses something almost every time it is repeated, and it sometimes comes back to me in a guise that is scarcely recognizable. The real story of the production of the Burbank potato is very simple. Something of the economic value of the discovery has been suggested in an earlier chapter, and will be touched on again before we are through. The importance of the discovery to me personally has also been suggested. It constituted my first commercially valuable plant development, and furnished a practical means of coming to California, where, doubtless, my experiments have been carried out on a far more comprehensive scale than they ever would have been in New England. Yet, on the other hand, I have always been disposed to think that if the potato had not furnished a means of migrating, and pointed out the possibilities of plant development, both these ends would have been accomplished by some other member of the garden or orchard family. Still there is a wise old proverb about praising the bridge that has carried you over, and for me, assuredly, the new potato served as a most important bridge. So I naturally look upon the development of the Burbank potato as marking an epoch in my life, and as standing quite apart from other plant discoveries. In the sense that it was my first important plant discovery, it must always remain the most important one.

A SIMPLE DEVELOPMENT

Considered as a problem in plant development, the origin of the Burbank potato was a relatively simple matter. There is no story of complex hybridizations and elaborate series of selections to be told in connection with it, such as we have heard in connection with sundry other more recent discoveries. Indeed the word discovery may be applied with peculiar propriety to the origin of the Burbank potato, because it all came about through the chance finding of a seedball growing on the stem of a potato vine among numerous other vines in an ordinary garden. Of course the observant eye was there to note the anomaly of a potato producing a ball of seeds in defiance of the usual Early Rose potato traditions. Also there was the receptive and inquiring mind of youth, to challenge the product and raise the question of what would result if these seeds were planted. These qualities, or something akin to them, must always be present where new phenomena are under observation, else no discovery would be made however lavishly the materials for discovery are laid before us. In many of my later discoveries, I myself brought the materials together and had a share in combining them and in directing and guiding the processes of nature through which new plants were developed. In the case of the potato, as just stated, all this work was done quite without my co-operation. When I came upon the seedball it was far advanced toward perfection, and my task consisted merely of watching it and making sure that the seeds were gathered and preserved, and in due course planted.

A SEEDBALL LOST AND FOUND

That the story should not altogether lack picturesqueness, I must record that my incipient discovery came very near being rendered futile by the accidental loss of the all-important seedball after it had been revealed. I had first seen the seedball, growing on an early rose potato vine, some time before it came to maturity. My mind was at once impressed with the idea that this might sometime be of value, inasmuch as this potato had never been known to bear seed. Moreover, I had for some time been on the lookout for potatoes that would offer opportunities for development, as those that were grown in the neighborhood at the time did not fully meet my ideas as to what a potato should be in form, size, color, production, and keeping qualities. This was as long ago as 1872, and it should be understood that at that time the potato, as ordinarily grown, was a tuber much smaller in size and less smooth and attractive in appearance than the ones with which the present-day grower is everywhere familiar. Moreover, the potatoes were wont to suffer from what was called dry rot. Of course the average gardener accepts the product of his vines and herbs somewhat as he finds them, with no clear notion that they could be made different from what they are. But I had been imbued from the outset with the idea that inasmuch as existing plants had evolved from inferior types, it should be possible to develop any or all of them still further. So my general attitude of mind toward the garden products was that of a workman handling plastic materials. And, as regards the potato, I had a very clear notion that the ones we raised might be very distinctly bettered if only the right way could be found. So the hint given by the seedball was instantly taken and day by day the ripening of this precious little receptacle was watched with the utmost interest and solicitude. Judge of my consternation, then, on visiting the potato patch one morning-with the thought in mind that now, probably, the seedball would be ripe enough to pick-to find that the coveted fruit had disappeared. With anxious attention I parted the vines and searched everywhere for the missing seedball. I went over every inch of the ground for many feet on all sides. But I could find no trace of the missing seedball. I was obliged finally to give up the search for the day, reluctantly admitting that I should probably never see again the little ball of seeds on which such high hopes and expectations had been based. Yet I could not believe that the seedball had been carried away, for no outsider visited the garden, and no one would have taken the slightest interest in the tiny fruit in any event. So day after day I returned and took up the search again. I covered the ground systematically in every direction, moving each vine, and anxiously scrutinizing the soil about its roots, and lifting every chance leaf under which the little seed receptacle might have lodged. And at last this patient search was rewarded. Several feet away from the original vine, snugly lodged at the base of another vine, the missing seedball was found. Whether it had been removed by some bird that had plucked at it inquiringly, thinking that it might furnish food; or whether some stray dog running through the potato patch had quite by accident broken it off and projected it to where it was found, I never knew. It sufficed that I had the precious seeds again in my possession, and I took good pains to see that they were safely stored for the winter. On removing the seeds from the capsule, it was found that there were twenty-three of them. The coming of spring was eagerly awaited to reveal what hereditary possibilities were stored in these seedballs.

TWENTY-THREE NEW VARIETIES

When spring came, I planted the seeds out of doors, as one would plant the seeds of beets or cabbages. The ground had been prepared with great care, and each seed was placed about a foot from its next neighbor in the row. But no special protection was given the seeds. Today I would not think of planting valuable seeds of any kind in this way. The risk would seem far too great. I should now plant them in boxes, after the manner described in the chapter on the care of seedlings, and give them individual attention in the greenhouse. As I look back upon the incident, I have often wondered that I was able to sleep at night while my precious seeds were thus exposed to any marauders of the animal or insect world that might chance to come upon them. But a good many times it happens that we pass quite safely and unwittingly through dangers that seem very threatening indeed when we look back upon them. And so it was with my twenty-three potato seeds. Every one of them sent a sprout through the soil in due course, and put out its tiny cotyledons, and grew into a thrifty vine. And although no vine of them all produced a seedball, each one developed a fair complement of tubers. Needless to say I watched their growth with solicitude, tentatively digging into a hill here and there as the season progressed, to note what such a novelty as a potato grown from seed would be like. Interesting developments were expected, but no one could have any very clear idea as to what these developments might be. But I certainly had not expected so remarkable an exhibition as that which met my eyes, when, late in the fall, the day came for digging the potatoes, and each hill in turn was carefully spaded and made to reveal its treasure. For as we went down the row, spading up one potato hill after another, we found in each successive hill a different type of tubers. One hill would show small potatoes of curious shapes; another hill, larger potatoes with deepset eyes; yet another, potatoes red in color, or with rough skins, or knotted and covered with bulbous tumors. But there were two vines that bore tubers that were instantly seen to be quite in a class by themselves. These were very large, smooth, white potatoes, excelling in all respects any vegetables of their kind that I had ever seen. The product of all the other vines but these two could be at once discarded. At best they only equaled the average potatoes of the early rose stock from which they sprang. But the two exceptional vines bore tubers that quite outrivaled even the best example of the parental stock. Not only were they superior in size, but they also excelled in symmetry of contour, in whiteness, in uniformity of size, and in productiveness. Among the twenty-one discarded potatoes there were, indeed, a few that were not without interest. One variety was red, and not unattractive, but it had not proved very productive, and most of the tubers decayed soon after they were dug. So this variety was obviously unworthy of further attention. Another vine bore potatoes that were pinkish in color, and having eyes so prominent that the long slender tubers seemed to be all eyebrows, the eyes reaching quite to tie center of the potato. Yet another was round and white, but too small to be of any value. As between the products of the two exceptional vines, there was not a very marked difference. The tubers from one averaged slightly larger than the other, slightly more uniform in size, just a little smoother and more attractive in appearance-in a word, in every way just a shade better. These best tubers were, of course, carefully preserved, and a considerable crop was grown from them next year by dividing the tubers and planting them in the usual way. And their progeny, multiplied year by year, until they are now gathered by millions of bushels each season in all parts of the world where this vegetable is grown, constitute the Burbank potato.

INTRODUCTION OF THE BURBANK

The twenty-three seedlings were grown, as just noted, in the season of 1873. The one incomparable member of the lot proved itself in the following season, and gave a goodly quantity of tubers all substantially identical with the original ones and obviously quite different from the usual potatoes then in existence. It required no very keen eye to see that a prize had been secured. But I did not at first know just what to do with it. I desired, of course, that the new potato should be introduced to the general public, realizing the economic importance of a potato that would produce two or three times as many bushels to the acre as the ordinary varieties, and at the same time give individual tubers of superior quality. But the first dealer to whom I offered the new potato declined it rather curtly, and I had some diffidence about approaching another. Finally, however, I mustered courage to bring the new potato to the attention of Mr. James J. H. Gregory, then a resident of Marblehead, Massachusetts. By way of introduction, I sent him a sample of the new potato. Mr. Gregory tested the potato by planting it, and was so pleased with the result that he sent word next season that he would be glad to talk with me. Accordingly I went to see him. I looked forward with pleasure to the visit, as Mr. Gregory had an interesting garden and a very complete seed establishment. But I was a little diffident about going, and so persuaded a friend, the lion. J. T. Brown, then a banker in Lunenburg, to accompany me. I shall always entertain the most vivid and pleasing recollections of the day spent in Mr. Gregory's gardens, and of the hospitality extended by the owner and his family. Mr. Gregory showed a basket of beautiful potatoes, which he declared to be quite the best he had ever seen, and which, he assured me, were the product of the sample I had sent him. He asked me to sell the potato to him outright, giving him the exclusive right of introduction of the new vegetable. And that, of course, was precisely what I wished to do. The matter of terms was not so easily adjusted. I had thought that $500 would not be more than a fair price for the new potatoes. But Mr. Gregory said that $150 was the most that he could pay. Other new potatoes were being developed, he said, and this one would not have the monopoly that it might have had a few years earlier. Had I developed it even two or three years sooner, he could have paid a thousand dollars for it. I was perhaps a little disappointed, but was contented to accept Mr. Gregory's verdict, and let him have the potato without looking farther. With the $150 that he paid, I came to California next season, having first delivered to Mr. Gregory a crop of the potatoes raised on my own ground and a neighboring piece of land. Mr. Gregory permitted me to keep ten potatoes. These I brought to California, and thus introduced the Burbank potato on the Pacific Coast. The name "Burbank seedling," I should explain, was given the potato by the purchaser. Mr. Gregory stated afterward, in a letter now before me, that he chose this name because he decided, "after pondering over the matter, that the one who originated such a variety deserved to have it bear his name."

PROGRESS OF THE BURBANK

It is not necessary here to trace the story of the spread of the Burbank potato from one region to another until its annual crop has been estimated to have a value of not less than seventeen million dollars. Suffice it that I personally introduced it in California, and that after the prejudice against a white potato had been overcome, the merits of the new tuber were so quickly recognized that the Burbank came to be the standard tuber on the coast from Alaska to Mexico. The U. S. Department of Agriculture aided in the distribution of the Burbank at an early day, sending it to various states, among others to Oregon, where it soon became exceptionally popular. The Burbank does its best on well drained, sandy soil, and in a moderately cool, moist climate. It thrives splendidly in the Sacramento and San Joaquin Valleys. There are single farms that raise from one hundred to one thousand acres each of Burbank potatoes; indeed, I received a visit recently from a gentleman who stated that his crop of Burbanks covers two thousand acres. In the region of Salinas, California, the conditions seem to be exactly suited to this potato, and the crop sent from this region brings a price so exceptional that the Salinas Burbank has come to be regarded as the standard for quality in California. Over six million bushels of the Burbank potato were produced on the Pacific Coast alone in the season of 1906, and the crop of that year probably did not differ greatly from that of each year of the past fifteen or twenty. In more recent years it has doubtless at least held its own. Of course all the Burbanks making up the enormous crop of the world have been produced by multiplication of the original single hill of tubers that grew from the one best vine among the twenty-three seedlings of the original potato seedball. That the enormously multiplied product of today maintains everywhere the characteristics of the original, offers an interesting proof that varieties do not "run out" if grown under suitable environments.

HOW TO EXPLAIN THE BURBANK?

But how shall we account for the original variety itself? I have told the story of its development without offering any explanation of the interesting phenomena observed. It remains to account not alone for the Burbank but for the twenty-two other varieties of potato that were its seedball sisters but which were allowed to perish, because they did not, on the whole, possess qualities that justified their preservation. Our studies of plant development through hybridization, in connection with numerous species of flowers and trees and orchard and garden fruits, supply clews that make the explanation of the origin of the new potatoes relatively simple. We have seen that a tendency to variation is everywhere introduced when different species or varieties of plants are hybridized. And although no conscious experiment in hybridization was involved in the case of these potatoes-inasmuch as I had no knowledge of the seedball until it was in actual existence-yet it is clear that nature had performed the experiment, and that I was enabled to take advantage of the results of her experimenting. To be sure it is more than likely that the seedball with which I worked was produced by accidental fertilizing of the pistil from which it grew by pollen from a neighboring plant; representing, therefore, the crossing of individuals of the same variety and not a true hybridization of different varieties; for all the potatoes in my garden were of one kind-namely the Early Rose. But the Early Rose potato is itself a crossbred variety. I am not sure that its exact history is known, but undoubtedly it is the product of the crossing of some other varieties of potato. The Early Rose was a seedling of the Early Goodrich, a white potato named after its originator, a clergyman who had been carrying on experiments in crossing the potato and raising seedlings. The crossing from which it originated occurred on the grounds of Mr. Goodrich many years before the time of its discovery. But of course that does not in the least matter, for every potato of a given variety, no matter how far removed from the original specimen of that variety in point of time, is of the same generation with that original so long as all are grown from the tuber. All this has been clearly explained again and again in dealing with the propagation of other plants from tubers or cuttings or grafts or by root division. It follows that the twenty-three seedlings were progeny of the second filial generation of the original varieties that were crossed and which produced the Early Rose. And this fully accounts for the extraordinary range of variation that the twenty-three seedlings manifested. We have seen many illustrations of this tendency to vary in the second filial generation of hybridized species or varieties. We have observed that the latent qualities of diverse strains of ancestors are permitted to come to the surface and make themselves manifest in the various individuals of a second generation, once the tendency to relative fixity has been broken up by hybridization. So the twenty-three diversified varieties of potatoes that grew from the single seedball merely furnish another illustration of a principle that our studies in plant development have made familiar. The case has interest, none the less, as presenting evidence from a new source of the application of a principle of heredity that can never fail to excite surprise however often we see it manifested. It follows that we should not necessarily expect the Burbank potato to breed true from the seed, even if by rare exception a seedball should be formed on a vine of this variety. But in point of fact it breeds absolutely true as to color and reasonably true in form, but not one of the seedlings ever compared in its combination of good qualities with the original Burbank. But of course this is a matter of no practical importance. Probably not one potato grower in a thousand ever gives a thought as to whether the potato produces seed. In practice the potato is grown from the "eyes" of the tuber, and the grower gets approximately the sort of tuber that he plants. Beyond that the matter does not concern him.

SEARCHING FOR NEW VARIETIES

But of course the plant developer must view the matter in another light. He must consider the potato not as a finished product but as an important vegetable that may be susceptible of still further improvement. So for him, doubtless, the chief interest of the story of the production of the Burbank variety must hinge upon what it can teach as to the possible production of still better varieties or of varieties adapted to different conditions of soil or climate from those under which the Burbank thrives.

THE SECRET OF FURTHER IMPROVEMENT

Obviously the lesson of the Burbank is that all further improvement must be sought through the crossing and hybridization of the existing varieties of potato, and the raising of seedlings. My own experiments in this direction have been extensive, and have led to some interesting results, even though the spectacular features of the production of the original Burbank have been lacking. As early as 1895, I produced a hybrid between the Burbank potato and a variety known on the Pacific Coast as the Bodega red. This was advertised, but was never introduced. A variety that was introduced only a few years after I came to California was a sport that appeared in a field of Burbank potatoes growing on my brother David's place at Tomales. There were five or six hills of vines that differed from the others in having larger tops and more vigorous growth as wvell as an altered appearance. They matured very late, and were found to have potatoes far less regular in outline than the ordinary Burbank but much larger and coarser, and produced in great abundance. Next year they were introduced through a San Francisco firm. But the potato did not differ sufficiently from the Burbank to maintain its individuality, and it is not now known as a separate variety. My most interesting hybridizing experiments have been with the wild or half wild species of potato that are indigenous to various parts of subtropical and tropical America. An account of some of these experiments was given in Chapter 9 of Volume II, to which the reader is referred. There, to be sure, the experiments in hybridizing the potato were classified as failures, inasmuch as they led to no commercially valuable result. But it will be seen that they did not lack interest from a scientific standpoint. In particular some of the results in crossing the Darwin potato (Solanum maglia) with the common potato through which a vine was produced that bore a remarkable fruit, were cited at some length.

INTERESTING HYBRIDS

Here I may refer a little more in detail to results of this hybridizing experiment that were not mentioned in the earlier chapter. The Darwin potato is a slender, erect-growing plant, bearing a tuber the flesh of which is usually bright yellow in color, and much subject to decay. In its stem and blossom, also, the plant is quite different from the ordinary potato, and it commonly bears a seedball that is larger than the seedball that the cultivated potato bears on rare occasions; the seeds themselves, however, being much smaller. I grew seedlings of the Darwin potato and improved them by selection until they produced tubers of enormous size, some of them weighing two to two and a half pounds. Then hybridizing experiments were carried out between the Darwin and the common potato. More than half a million seedlings of hybrids between these two species were raised. The Darwin potato is much more fixed in its characters than the cultivated potato, and these characteristics proved largely dominant in the progeny of the first generation, this dominance extending to the tubers themselves, which resemble their wild ancestor in size, color, irregularity of form, deep eyes, and tendency to decay.

EIGHT-FOOT VINES

There were, however, some astonishing anomalies manifested by the hybrid progeny. Some of the vines grew so prodigiously that they reached eight feet in every direction from a single root; and the potatoes they bore grew on long stems or runners which spread nearly as far. In other cases the vines were compact, in striking contrast with their straggling sisters. As to the potatoes themselves, some were quite small, and the larger ones revealed the most curious colors-bright crimson, scarlet, bright yellow, white, black, and purple; the various colors being sometimes intermingled in the same tuber in the most curious way. Some were black from skin to skin, others had a red center with an outer layer of purple about a quarter of an inch thick. Others were white or yellow, writh purple veins radiating from the center of the potato to the eyes. In yet other cases the flesh of the potato was variegated with crimson and yellow, purple and white, blended into every imaginable form and figure; so that when the potatoes were sliced the effect was grotesque and sometimes fascinating, as the cut surface revealed landscapes, faces, geometrical figures, cloud effects, varying kaleidoscopically with each new slice. Notwithstanding the great interest of these hybrids, I did not think them worthy of introduction, as they were curiosities rather than a practical commercial production. Yet it seems not unlikely that a more extended series of experiments in hybridizing and selection in which strains of the Darwin potato are introduced might result in a product of real value. Some of the improved Darwin seedlings produced tubers of exceptional size, though as before stated, much subject to decay. If the breeding experiments were conducted along right lines it would probably be possible to produce in later generations a hybrid that combined the large size of tuber of the Darwin with the keeping qualities of the cultivated potato. It is really of great importance that the experiments should be repeated and carried forward to a successful issue. What has just been said as to the curious results of hybridizing experiments with this species will sufficiently indicate that experiments of this kind will not be lacking in interest. Experiments already far advanced at Santa Rosa, using the Solanum Cominersoni, a species growing wild in the region oi the Mercedes River, in South America, for a time gave great promise. The hybrids between this plant and the cultivated potato showed great improvement in some directions, but all the seedlings lacked. one desirable character or another. The chief trouble was the bitter principle which was transmitted by the commersoni to almost all its hybrid seedlings. I have, however, a very complex hybrid that is about to be introduced-the fruit is of a reddish color, almost apple shape. The plant is very productive, and the tuber is of fine quality. There are various other wild Solanums growing, as did these original potatoes, in South America, that might advantageously be tested as to their hybridizing possibilities in connection with the cultivated varieties. It need scarcely be added that such experiments will ultimately be made in which all allied species of potato will be tested; and it is highly probable that this will lead to the development of new varieties of tubers that will surpass the potatoes of today as markedly as these surpass the wild ancestors from which they have been developed in comparatively recent times.

-I had been imbued from the very outset with the idea that inasmuch as existing plants had all evolved from inferior types, it should be possible to develop any or all of them still further.

This text is from: Luther Burbank: his methods and discoveries and their practical application. Volume 7 Chapter 9