CLUB ROOT DISEASE.

Stratford Evening Post, Volume XXV, Issue 11, 14 January 1915, Page 8

CLUB ROOT DISEASE.

CWEDE TURNIPS AFF.EOTED. An esteemed correspondent writes as follows with reference to the Club Root Disease, otherwise Finger and toe, anbury or canker disease: It attacks many species of cruciferous plants and is especially destructive to the species of Brassica such as turnips, swedes and cabbages, but it is worthy of note that certain of the races of these plants are more subject to the disease than others. Cauliflowers and Brussel's sprouts, for example, are very liable to it, whilst the kales are more capable of resisting it to a certain extent. The disease appears to make most progress in the summer, the earlier spring vegetables in gardens often escape altogether or suffer very little from it. Infected young plants show a regular thickening and knob-like swellings on their roofs. The diseased parts when cut across are solid and'of greyish color, mottled with small white opaque patches. As the plants increase in age, the swellings become larger, often reaching the size of a man's fist. The other parts, of the plants develop very slowly, as practically all the nutriment is expended in the growth of the swollen diseased roots. The club parts alter a time turn brown and decay. 1„ dry soils the rotten portions hecome 'brittle and fall into powder or small fragment.-,, while in damp, stdf soils the decayed mass is semi-liquid, and throws off an offensive odour. Although the plants produce fresh fruits when the natural roots are attached, these soon become affected by the disease, and on pulling up a diseased plant a mere blunt woody stump is often found to be all that remains in the ground.

The cause: Club root is caused by an organism named Plasmodiophora Brassicoe, which is generally classed with species of slime fungi. This feeds on the food produced by the plant until the decay of the diseased part takes place and sets the minute organisms free by millions in the soil. How long they are known to live in the soil is somewhat unsettled, but it has been proved to attack a crop even after two or three years. ' Prevention: All plants which are found to be affected with this blight should be pulled up previous to their becoming decayed, and burnt. It is a great mistake to allow stock of any description to feed on any diseased crop, as they would only carry the disease and spread it through their droppings. Avoid cropping with swedes or turnips for at least three 'years. Crops such as grain, mangolds, potatoes, etc. : Apply a fairly heavy dressing of either basic slag or lime.