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GOOSEBERRY
  


succulent. When large fruit is desired, plenty of manure should be supplied to the roots, and the greater portion of the berries picked off while still small. If standards are desired, the gooseberry may be with advantage grafted or budded on stocks of some other species of Ribes, R. aureum, the ornamental golden currant of the flower garden, answering well for the purpose. The giant gooseberries of the Lancashire “fanciers” are obtained by the careful culture of varieties specially raised with this object, the growth being encouraged by abundant manuring, and the removal of all but a very few berries from each plant. Single gooseberries of nearly 2 oz. in weight have been occasionally exhibited; but the produce of such fanciful horticulture is generally insipid. The bushes at times suffer much from the ravages of the caterpillars of the gooseberry or magpie moth, Abraxas grossulariata, which often strip the branches of leaves in the early summer, if not destroyed before the mischief is accomplished. The most effectual way of getting rid of this pretty but destructive insect is to look over each bush carefully, and pick off the larvae by hand; when larger they may be shaken off by striking the branches, but by that time the harm is generally done—the eggs are laid on the leaves of the previous season. Equally annoying in some years is the smaller larva of the V-moth, Halias vanaria, which often appears in great numbers, and is not so readily removed. The gooseberry is sometimes attacked by the grub of the gooseberry sawfly, Nematus ribesii, of which several broods appear in the course of the spring and summer, and are very destructive. The grubs bury themselves in the ground to pass into the pupal state; the first brood of flies, hatched just as the bushes are coming into leaf in the spring, lay their eggs on the lower side of the leaves, where the small greenish larvae soon after emerge. For the destruction of the first broods it has been recommended to syringe the bushes with tar-water; perhaps a very weak solution of carbolic acid might prove more effective. The powdered root of white hellebore is said to destroy both this grub and the caterpillars of the gooseberry moth and V-moth; infusion of foxglove, and tobacco-water, are likewise tried by some growers. If the fallen leaves are carefully removed from the ground in the autumn and burnt, and the surface of the soil turned over with the fork or spade, most eggs and chrysalids will be destroyed.


Fig. 1.—A Fungal Disease of the Gooseberry
(Aecidium Grossulariae)

1, Leaf showing patches of cluster-cups on surface; 2, Fruit showing same; 3, Cluster-cups, much enlarged.

The gooseberry was introduced into the United States by the early settlers, and in some parts of New England large quantities of the green fruit are produced and sold for culinary use in the towns; but the excessive heat of the American summer is not adapted for the healthy maturation of the berries, especially of the English varieties. Perhaps if some of these, or those raised in the country, could be crossed with one of the indigenous species, kinds might be obtained better fitted for American conditions of culture, although the gooseberry does not readily hybridize. The attacks of the American gooseberry mildew have largely contributed to the failure of the crop in America.

From George Massee's Text-Bank of Plant Diseases, by permission of Duckworth & Co.

Fig. 2.—Gooseberry Mildew (Microsphaeria Grossulariae)

1, Leaf attacked by the fungus; 2, Fructification or perithecium; the end of one of its numerous appendages is shown more highly magnified in 3, 4, 5, spore sacs (asci) from the perithecium, containing spores.

Occasionally the gooseberry is attacked by the fungus till recently called Aecidium Grossulariae, which forms little cups with white torn edges clustered together on reddish spots on the leaves or fruits (fig. 1). It has recently been discovered that the spores contained in these cups will not reproduce the disease on the gooseberry, but infect species of Carex (sedges) on which they produce a fungus of a totally different appearance. This stage in the life-history of the parasite gives its name to the whole fungus, so that it is now known as Puccinia Pringsheimiana. Both uredospores and teleutospores are formed on the sedge, and the latter live through the winter and produce the disease on the gooseberry in the succeeding year. In cases where the disease proves troublesome the sedges in the neighbourhood should be destroyed.

A much more prevalent disease is that caused by Microsphaeria Grossulariae. This is a mildew growing on the surface of the leaf and sending suckers into the epidermis. The white mycelium gives the leaves of the plant the appearance of having been whitewashed (fig. 2). Numerous white spores are produced in the summer which are able to germinate immediately, and later small blackish fruits (perithecia) are produced that pass uninjured through the winter liberating the spores they contain in the spring, which infect the young developing leaves of the bush. In bad cases the plants are greatly injured but frequently little harm is done. Attacked plants should be sprayed with potassium sulphide.

From the Journal of the Board of Agriculture (May 1907), by permission of the Dept. of Agriculture and Technical Instruction for Ireland.

Fig. 3a.—American Gooseberry Mildew (Sphaerotheca mors-uvae). Plant with leaves and fruit attacked by the fungus.

An allied fungus, Sphaerotheca mors-uvae, of much greater virulence, has recently appeared in England, causing the disease known as “American gooseberry mildew” (fig. 3a). In the main the mode of attack is similar to that of the last-mentioned, but not only are the leaves attacked, but the tips of the young shoots and the fruits become covered by the cobweb-like mycelium, the attack frequently resulting in the death of the shoots and the destruction of the fruits. After a