[Enclosure]

Report

on the

Growth of the Potato from the Seed.

By James Torbitt.³

Belfast, 15th November, 1879.

For the last five years I have been growing each year 5,000 new varieties of the plant, of which I have preserved some of the best and destroyed the others.

The first two years, 1875 and 1876, the varieties were grown from seeds of self-fertilized flowers; the succeeding years from seeds of flowers cross-fertilized by Mr. Darwin’s advice, instructions, and assistance;⁴ and the results are as follows:—

Of the white varieties of 1875, there is one which appears to be absolutely disease-proof, as regards both the foliage and the tubers. The tubers are globular, of excellent quality, and the yield large.

Another is kidney shaped, of immense yield and good quality; but it is susceptible to disease to the extent of two or three per cent.

Seven other kidneys are very early, of immense yield, and excellent qualities; but they are diseased to the extent of about ten per cent.

Of the red round varieties of 1875, four are perfectly sound up to this date, and some ten or twelve others were so last year. These I gave to gentlemen in the North of Ireland last spring, on condition that they return to me an equal weight of the produce this autumn. As yet I have had only one report—it is: “That that variety is absolutely free from disease, and of good quality, but not of a particularly large yield.”

The Bishop of Down also found a round red variety of 1875 from self-fertilized seed which I had sent him; which is disease-proof, of large yield, excellent quality, and which produces almost no small tubers.⁵ A specimen of this variety I have the pleasure to send to Mr. Darwin.

The varieties of 1876, which were not of much value, I gave all away, except one which is white, round, of good quality, and until the present year of very large yield: it is believed to be disease-proof in the foliage as well as the tubers; and a specimen of this variety, also, I have the pleasure to send to Mr. Darwin.

Of the crossed varieties of 1877 and 1878, and the twice crossed varieties of 1879, I have something like three or four thousand which, for so far, appear worthy of further trial. Large numbers, particularly the 1879’s, are absolutely free from the disease; but no doubt many of them will succumb during the winter. In the spring I propose to wash and examine them, and to destroy all diseased to the extent of ten per cent.

(Pending the production, all over the kingdom, of disease-proof varieties, I think it would be better not to destroy any very prolific and marketable variety, diseased only to the extent of ten per cent.)

With regard to the future of these new varieties, I know that a variety called Skerry Blue practically resisted the disease for some twenty years, and I hope with some confidence that some of these new varieties will do so also.⁶

The Skerry, for the last few years, has become more and more susceptible to disease, and the yield has fallen off so far that it is being thrown out of cultivation.

But, setting aside the disease altogether, I am of opinion that new varieties should be continually coming forward; because I find that the new young varieties are very much more prolific than the old.

Knight found a variety which yielded 34 tons per acre.⁷ I have found varieties which yield from 12 to 24 tons per acre: while the average yield over the kingdom probably does not exceed eight or nine tons.

Further, I suspect, that by the scientific cultivation of the plant, England may be made to compete successfully with the United States in the production of beef, pork, butter, and cheese.

Further, I am of opinion, that the plant, in order to obtain its maximum yield, must be grown from its seed each fourth year, and, as of course, carefully cross-fertilized.

With regard to the cost of cultivating these varieties next season, I think £300 or £400 would be sufficient, and £100 would suffice to grow the number of seedlings I have arrangements made for, that is 5,000: but I hold in my hand hundreds of thousands of crossed seeds, and I believe that the more of them which shall be sown next spring the better it will be for the public.

(Signed), | JAMES TORBITT.

According to promise given to Mr. Torbitt in the Spring of 1879, that I would give a truthful statement of the different kinds of potatoes—say from above four thousand varieties grown on my farm—from the potato berries and hybridized while in bloom:

I herewith certify that the red, round kinds of 1875 are better than the old varieties hitherto grown, and that they are perfectly free from disease.

In the year 1876, I grew none; the red and white varieties of 1877 are better than those of 1875, and some hundreds of kinds are perfectly free from a single speck of disease; and also the red and white kinds of 1878 are in every way superior to any other kinds I have ever seen.

My experience convinces me that new varieties of the potato should continuously be propagated from the berries to replace those continuously wearing out, and which experience proves, at about ten or fourteen years, becomes an effete plant.

ABRAHAM GREEN.

Trumra Villa, Moira, Co. Down. | 12th 11th month, 1879.