Success with Small Fruits

by Edward Payson Roe

Without doubt, new diseases and enemies to the strawberry will be developed in the future, and as they come we must experiment till we find some means of mastering them.

RASPBERRIES AND BLACKBERRIES

These two fruits are so near akin that they are subject to the attacks of the same diseases and enemies. The most fatal scourge of red raspberries that I have seen is what is called at Marlboro' the curl-leaf; and, if unchecked, it will eventually banish the famous Hudson River Antwerp from cultivation. As yet, no remedy has been found for it that I am aware of. I believe it to be contagious, and would advise that the plants be dug out and burned immediately, and that plantations of strong, healthy plants be made on new land that has never been in raspberries. I also suggest the free use of wood-ashes and well-decayed compost. As far as my experience goes, this disease is confined to foreign varieties, and almost wholly, as yet, to the Antwerps.

Mr. Fuller, in the paper already named, describes a disease among blackberries that resembles the raspberry curl-leaf so closely that it may be identical, and spring from the same cause.

"Some ten years ago, the cultivators of the blackberry in various parts of New Jersey noticed that the ends of the young, growing canes, in summer, would occasionally curl, twist about, and often assume a singular, fasciated form, resulting in an entire check to their growth. The leaves on these infested shoots did not die and fall off, but merely curled up, sometimes assuming a deeper green than the healthy leaves on the same stalk. At the approach of winter, the infested leaves remained firmly attached to the diseased stems; and all through the cold weather, and far into the spring, these leaf-laden and diseased stems were a conspicuous object in many of the blackberry plantations of this State.

"If the infested shoots are examined in summer, thousands of minute insects, of a pale yellow color, and covered with a powdery exudation, will be found sucking the juices of the succulent stem and leaves, causing the crimping, curling, and twisting of these parts as described.

"This parasite resembles somewhat an ordinary greenfly (Aphis) or plant louse; but, according to the observations of Professor Riley, it belongs to the closely allied Flea-lice family (Psyllidae), distinguished from the plant-lice by a different veining of the wings, and by the antennae being knobbed at the tip, like those of the butterfly, the knob usually terminating in two bristles. These insects jump as briskly as a flea, from which characteristic they derive their scientific name. The particular species in question was called by Professor Riley the 'Bramble-Flea-louse (Psylla rubi [Footnote: "It can not be distinguished from Psylla tripunctata, Fitch (Catalogue of Homoptera, etc.), and, what is most singular, the same species is very common on pine-trees all over the eastern part of the continent, from Florida to Canada.">[),' in the American Entomologist (Vol. I., p. 225). It has increased rapidly during the past half-dozen years or more, and unless fruit-growers make a more vigorous fight than they have yet done, it will soon get the mastery of many blackberry plantations. The only practical method as yet discovered for checking the ravages of this insect is to cut off the ends of the infested canes and burn them. This operation should always be performed either in the morning or during cool, wet weather, else many of the insects will escape; and at all times the severed shoots should be immediately dropped into bags, and in them carried to the place where they are to be burned, and there emptied into the fire. If every one having blackberry bushes in their gardens would practice this method of destruction, this pest would soon cease to do much harm."

There are species of borers and gall insects that attack these two fruits, but as yet they have not become formidable. All infested canes should be cut out and burned with their contents, or else the pests may so increase as to cause much injury.

The larvae of the Selandria rubi, an insect nearly related to the imported currant worm, and known as the raspberry saw-fly, is destructive in some regions. It is semi-transparent, and so like the foliage in color that it could scarcely be detected, did not the ragged, perforated leaves indicate both its presence and its mischief. This worm measures half an inch in length, when fully developed. It has two black eyes, like spots, upon a green head, and usually a slightly fuzzy body. The remedies recommended are the same as those used against the currant worm. I have had no experience with this pest.

The Orange-rust (Uredo rubrum) is one of the worst of foes to both the blackberry and raspberry—the Rubus occidentalis, or black-cap family, suffering the most, usually. I have seen fields of the Early Wilson and Kittatinny blackberries in New Jersey that presented a melancholy appearance. It is believed to be very contagious, and it can be spread by both trimmer and pickers. Mr. Chas. A. Green, of Monroe County, N. Y., writes: "The end plant of a row in my garden was affected, and I let it remain, as an experiment. In three years, nearly every plant in the row was more or less diseased. We have tried picking the leaves and cutting back the canes, without relief, and have found that the only safe method is to dig out and destroy all affected plants without delay." Mr. Fuller says that "application of lime, salt, or some similar substance, may check the disease; but I know of no remedy except that of rooting up every affected plant, and burning it." Mr. Downing recommends the same course. It is one of those evils that should be stamped out at once. If a plantation were generally affected with this yellow symbol of contagion, it would be well to destroy all the plants, and, obtaining new, healthful stock from a distance, start again on different grounds. Should the snowy tree-cricket become very abundant, it might cause much injury, chiefly by cutting off the leaves, as the ordinary cut-worm serves the stem of a young plant.