This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
In the October number of the Horticulturist, the Georgia Committee, in their report on grapes, say: "As Le Conte observes, ' although, among some families of plants, hybrids occur naturally, or may be formed artificially, yet it is difficult to understand how this can be the case in the genus Vitis,' etc, and that this process of hybridizing the grape is impossible, ' on account of the minuteness of the flower and the parts of fructification,' he might hare added another difficulty: the petals are caducous, and cohere at the tips, forming a little cap, which, in the act of falling off whole', draws over, from one side or the other, almost invariably, the pollen from its own stamens upon the pistil. The chances then are that the operation on so minute a flower, in the act of removing this cap and the stamens, would have already fertilized the pistil before applying the pollen of the species or variety selected. We would not, however, assert that hybridization, naturally or artificially, is absolutely impossible, but nearly so".
From the result of this experiment, the opinions of Le Conte and the Georgia Committee, it would seem, must be conceded untenable, and the " other difficulty" obviated, if it is considered the cap and stamens should be artificially removed before the anthers are ready to burst, dispersing their pollen. Even, as we have usually noticed in many operations, when the cap naturally falls off, the anthers do not burst immediately.
It was the opinion of some very noted grape growers, although they and some learned botanists at once, from examination, pronounced these vines hybrids, that many would turn out staminate and totally unproductive plants, and the opinions of others, as, also, a writer in the December number of the Horticulturist remarks, the experiment would not succeed, for the reason that " there may be physiological peculiarities which often forbid the intermixture of as closely allied plants as the different species of grapes."* AH these objections seem put to rest by this experiment, the whole number of vines (about twenty-five) which have shown blossoms having generally set their fruit well, and many in the highest degree of perfection. (To be continued).
[Remarks. - When we wrote that "the efforts of the hybridizer were yet to be heard from," we meant that a grape adapted to general cultivation, raised in that way, had yet to be introduced. We are glad that our friend misunderstood us, as it has brought forth the above statement of valuable experiments, which will be read with interest by many. The conclusion shall be given next month.
The great barrier to the successful cultivation of the foreign grape in the open air, is not so much a want of hardiness as its liability to mildew. When planted on a dry soil, as all grapes ought in any case to be, the foreign grape will stand very nearly as much frost as the native kinds. In cases where it is killed, the Isabella and other native grapes generally die also. In those parts of the States where the temperature is more regular, or where the changes from a very dry to a moist atmosphere are not sudden or extreme, and, consequently, the causes which are known to favor mildew do not exist, the foreign grape can be ripened with fair success. In the region of Seneca Lake, and in many parts of Canada, there is little difficulty found in ripening it, notwithstanding the severity of the Canadian winters.
Of all the foreign grapes, the Golden Chasselas seems less liable to mildew when grown in the open air than any other we have seen tried, and we would recommend it as one of the best to experiment with in hybridizing. - Ed. H].
* That this opinion is incorrect, see, also, the results of an experiment on the Isabella, a native of a Southern species, by I. F. Allen, Esq., Salem, Mass., in an article by Rev. J. L. Russell, in Proceedings of the Essex Institute, vol. i. p. 195,1854.