Page:Treatise on Cultivation of the Potato.djvu/47

 8 1st May, and too late.

9. With four exceptions they were only spotted on the leaf.

10. None of tubers but four were diseased.

JOHN SLOAN."

2em

.,

,–I am sorry that I have not a more favourable account to give of the produce of the seed you were kind enough to send me. Being too late in applying to you for it, the crop did not reach maturity before disease set in and checked the growth. My opinion is that the seed should be sown early in March, so that the plant might appear by the middle of April. I did not succeed in having any tubers larger than beans. My efforts have been principally directed to the rearing of new tubers of old varieties; that is new white rocks, and now the white rock seldom produces apples. In fact all our approved varieties very seldom produce seed, and it is very difficult to renew the sort when worn out by age. A neighbouring farmer has succeeded in rearing a new Skerry Blue identical with the old, and without the thick skin characteristic of that variety. He has experimented on the White Rock, but can only produce a variety of Red Rock therefrom. Might not something be done in the way of fertilizing flowers with pollen of approved varieties. Another important question to be answered, is, how are the spores of the disease propagated? Do they propagate in the ground, or only lie dormant there? What effect would be produced by destroying all the potato haulms in the country for several years before visited by disease? In my opinion all investigations with regard to this subject have been unproductive, because they were conducted by scientific men who knew nothing of the practical aspects of the question, or by uneducated persons who had no idea of the probable causes of the disease, and who could therefore only employ empirical remedies. Now that a gentleman of scientific attainments and practical experience [I regret that I cannot accept of the soft and flattering impeachment, J. T.] like yourself, sets about the work, there is every hope of eventual success. I am, Sir, yours very truly,

JAMES CRAWFORD.