THE VINE DISEASE IN MADEIRA
TO THE EDITOR OF THE TIMES
Sir, –At a time when the attention of all more or less interested in the cultivation of the vine is being directed to the subject of the phylloxera, it may perhaps interest some of your readers to learn what success has attended my humble efforts to solve the problem presented to vine-growers. It may as well to state at once that a radical cure can hardly be hoped for. We must be satisfied if at a moderate cost this scourge can be so far held in check as to enable the vine to maintain a healthy growth and to bring its fruit to perfection. The chief difficulty in the way has been to discover an agent potent enough to destroy the pest underground without at the same time injuring the vine. After trying in vain various suggested remedies I was led, in consequence of observing the effect produced by Canada balsam and turpentine in mounting specimens of the phylloxera for the microscope, to treat with a somewhat similar preparation my sick vines. The result cannot but be considered satisfactory, inasmuch as, instead of a rapidly diminishing crop for the last two years, there has been considerable increase in the amount of wine produced by these vines. My treatment is simply as follows:– In the autumn and winter I cause the underground stem and principal roots of the vines which are to be treated to be laid bare of earth as far as can be conveniently and safely done, removing and causing to be burnt or plunged into boiling water the loose bark, which is generally teeming with insects. I then apply with a brush a coating of turpentine in which sufficient resin has been dissolved to render it decidedly sticky. The proportion is about 3 1/2 oz. of finely powdered resin to a quart bottle of turpentine. Solution to be assisted by heat. I take this opportunity to manure the vines, so that one removal of the earth shall suffice for both operations. The roots when tolerably dry are covered with earth. The mixture kills all it comes in contact with, and, in whatever other way it may act, continues to present, in consequence of its being unaffected by water, an impassable barrier to the passage of the insect to the upper world. Several thousand vines have been treated by me in this way in the course of the last two or three years, and although a the time of treatment they were teeming with phylloxera, they have thrown out strong shoots, produced good crops, and have preserved the dark green colour of their foliage through the past trying season. The cost of their mixture is trifling, and, as far as I have seen, the operation need not be repeated oftener than once in two or three years.
I remain, Sir, your obediant servant,
Maderia, Sept. 12. THOMAS S. LEACOCK