676 Journal of Agriculture, Yicti>ria. [10 Oct., 191 i. 



h, unfortunately, in certain (juarters, a readiness to employ the word 

 Bacteriosis as an easy explanation of any obscure plant disease, and tor 

 this reason one hesitates before using it. The best French authorities,, 

 however, now very generally attribute the diseases under review to the 

 presence of bacteria in the \essels and tissues of the vine. They con- 

 sider that the infection may be conveyed from diseased tO' healthy vines 

 by the secateurs u.sed when pruning. They recommend that cuts be 

 disinfected with a 3 per cent, copper sulphate solution, if the disease be 

 at all prevalent. It would appear logical, in such a case, for the pruners 

 to carry a small pot of liquid disinfectant into which their secateurs 

 could be dipped. 



Chlorosis. — This disease, which manifests itsi-lt by the leave.-; of 

 the vine being yellow instead of green, especiallv in spring, and inter- 

 ference with healthy growth generally, is in almost every case due to the 

 action of excess of lime in the soil, on vines grafted on resi.stant American, 

 stocks unsuited for limey .soils. Though of little importance in the majority 

 of Australian soils, owing to their low lime contents, the question has been 

 one of vast importance in Southern Europe, and it must l)e briefly men- 

 tioi:ied here. It cannot be gone into in detail, nor is it necessary to do 

 so. In cases where the growth of the vine is \-ery considerably interfered 

 with the di-sease is often termed Coftis. 



Brunissure. — This, curious disease, which manifests it.self by the ap- 

 pearance of dark Ijrown spots or blotches on the leaves after midsummer, 

 has given ri.se to much discussion. Messrs. Viala and Sauvageau attributed 

 it to the development of a Myxomycetous (slime-forming) fungus which 

 they named Plasmodiopliora viUs* in the interior of the leaf cells. 

 Other authorities consider that this discolouration of the foliage 

 is simply due to unfavourable weather conditions, whilst, according 

 to Profes.sor Rayaz. it would be the result of over-production of fruit or, 

 in other words, of overwork by the vine, brought about by excessively long 

 pruning or other cau.ses, such as climatic conditions very favourable to 

 heavy crops. He considers that more than one obscure di.sea.se of the vine 

 is due to this cause, and that over-production may in certain cases even lead 

 to the death of the plant. The point is worthy of attention and should 

 serve as a warning against the unduly long pruning of our newly re- 

 constituted vineyards. Overloading of such vines in their youth would 

 certainly be most injudicious, and it would be only rea.sonable to expect 

 that such would militate against a continuance of heavy yields. 



Though in some years Brunissure has been sufficiently prevalent to 

 cause alarm and to result in damage to the fruit, through interference with 

 normal development of the foliage, such se\ere visitations are unusual in 

 France, where the disease is only an exceptional occurrence. So far, \^o 

 treatment has been found capable of satisfactorily dealing with it. 



Ercissement. — This is rather a climatic affection than a di.sea.se, and 

 is the term given to the influence of drought and insufficient summer 

 cultivation. The berries remain small and ac(]uire a characteristic blue 

 tint after mid.summer or just about the -time when they ought normally 

 to be changing colour. The fruit, when ripe, is small, contains little 

 juice or sugar and yields a wine of poor cjuality. This would appear to- 

 be a les.s aggravated form of what has been termed " grape shrivel " in 

 California. 



* Professor Vial.a also attrilmtes the obscure Anaheim disp.ase of California to ,an allied fudfrns, which 

 he has named Phis mod iophora C'aHfornica. This view, howe\ er, is not shared by Califoriiian authorities. 

 Microscopic observations of these slime fuiigri are ditficnlt and delicate. 



