CLUB ROOT.

Dominion, Volume 6, Issue 1642, 8 January 1913, Page 10

CLUB ROOT.

A-CABBAGE-PATCH TROUBLE. \ i Most-gardoners have had some experience of club-root in their cabbages, and havo -found that plants which arc affected by. the disease seldom grow to maturity,'. .It is au' easy' matter to 1 detect ■plants which - havo, the. disease,* as they liavo a wilted appearance during the dnj', although they; recover at niglit. . The disease is found to ,bo. worst.-on clay soils .that are deficient in lime. In a soil in which : sorrel flourishes the grower Should bo oil the' alert for _ the disease, as it is likely to develop rapidly. When a section of an .infected root is examined undor the -microscope, it will be found that the larger cells are filled with a •slimy.- substance. ' These are infested with the. slime mould, and on account of the presence of this parasite, the cells undergo reniavknble enlargement, and an influenco- .is / cpmmunicated -to the outer 'iieiglibqiiring'. cells,. so that the roots becbino' much swollen and distorted. Ihis fungus obtains entrance ;Vto the cells of the growing root,. and there robs the infested.tissue of its vital. fluids, and, gathering .hew forces in itself, fills .'tho cells with'its own substance. This seini-iluid material then begins, the'process of snore formation, which results iri the produc--lion of . millions of .minute'-bodies,' each' of which is - capable of a new growth, ..when conditions ftro favourable... By the ;decay'of the roots, ' which takes place rapidly, and with much'offensive odour, -'the spores are set free in the soil.' These spores there germinate by producing movinj; .bodies capable, of -penetrating, or. 'being absorbed by the thin walls of tho hair and other superficial: cells of tho root. The soil becomes, diseased in the. 'sense that tho gems formed in-the swelling:;, and -other distortions of. the roots, - are' set free, and tho earth_ holds th enl for .an indefinite length of time. From a consideration, of the, nature of the dubroot fungus,' and a knowledgo of the different'kinds of plants infested- by it, thero may bo .some suggestions gatherwl. .'as -to preventive measures,,-: WTien.it is understood' that the-,"club-root, ...and all the injury -to tho crop accompanying: it. are due to on internal subterranean para.'site, it becomes 5 evident - that -no- treats ment to which .the: infested' plant may ;be subjected can give promise of a cure. -Preventive measures ' must,. be _ relied, upon,' aiyl, : in the first place, all tha re:fu'se":of ,'a. cabbage, , turnip,;-or other infected' crop should be removed .from the soil and burned. '' In view of-the fact that-the soil may become Jess impregnated with the germs during the growth of a crop susceptible to the-(lis-case, it is evident that a wise precaution consists-in a jmliciousrotatiori'of orops,. .Tust what that rotatipn, should' be is. a question; for.' each grower -to decide for ■himself,' Jiut. for 'thfe best results, cab-, bages or any allied: crop should, not lie upon the soil ofte'ner-than once in three years. Cabbage, kale, rape, tiirnips, or radishes' should, not follow each other it "club-root" is prevalent. It' is possible to, gehrelief- by the use-, of lime, and, by its constant use, at the rate-of 75' bushels (2 'tons)-: or so per aero .each year, cabbages have been grown at frequent-intervals—almost yearly, upon - the same soil. .-It-is likely :, that a soil' naturally - abounding : in lime! niay. be the. best suited for.cruciferous crops ro;f« .as. -club-root" is , concerned: -.: Seedlings should Iw examined carefully, and. if .they show signsof consigned to tho fire. .-;. .. .- ' • "V