—Sulphur Spray.—

Otago Witness, Issue 2622, 15 June 1904, Page 10

— Sulphur Spray.—

This is a good fungicide for mildew and . damping-off fungi, also excellent for insecticidal purposes. Take i Flour of sulphur, 101b Caustio soda, pulverised 90 per cent., 201b. Or 70 per cent., 81b. "Water, lgal. Place the flour of sulphur in a wooden tub large enough to hold Bgal or lOgal of wat&r; pour in lgal of water and mix with th© sulphur until all the sxilphur is moistened. Add the caustic soda, and keep stirring until all the soda is dissolved; the mixture becomes very hot, turns brown and becomes liquid ; now add enough water to make 7gal, strain into jars or bottles with airI tight ftoppers, and mark "stock solution." For dampmg-off fungi applied to the soil I use one pint of the stock solution to 12gal • of water; for mildew of tke vine or other plants us© one quart stock solution, to 12gal of water. This solution, applied in proportions varying from ono pint to one and a-half pints to 12j>'al water, is most useful for controlling red spider and bryobda. — Ammoniacal Copper Carbonate Solution. — This is an excellent and efficient fungicid© that may be applied to the soil for destroying soil- inhabiting fungi. This has another advantage over Bordeaux mixture in that it discolours fruit and foliage only slightly, enabling on© to use it on greenhouse plants or on th© foliage of ornamental plants without rendering them unsightly, as would Bordeaux mixture*. It can ba purchased ready for uso or prepared, according to instructions in Leaflet No. 10. — Bordeaux Mixture. — For ordinary fungi, against such dis&ases as apple scab and other diseases of farm and garden crops, this is the best fungicide w© have at present, but it is of little value in treating fungi which live in the soil and attack plants in the rootg or below the surface. It would ba interesting and profitable to review tho history of events leading up to its discovery, and also leading to its perfection, but such review^ would occupy too much, space. Its essential ingredients fof making are: — Freshly-slaked lime of the best quality and copper eulphat© solution — the. fungicidal value lies in the copper. The quality of the lime and method of slaking it, mixing the two ingredients togethier, have, much influence on the mixture. There are many recipes for making Bordeaux mixture, the proportions of "Milestone, lime and water varying. A most satisfactory formula is what is known as the 4-5-50 formula. Many recommend stronger preparations-, such «is the 6-4-50, but beside being more expensive they are a wast© of material. Only the most minute quantity, of copper, possible- is necessary^ to produce the required effect as a fungicide, and this should b© applied in a wholly insoluble form, heno© Bordeaux mixture should be prepared in such a manner as to entirely -deoomposo the copper sulphate and neutralise th© sulphuric acid. Th© 4-5-50" formula is based on the fact that five parts of lime neutralise four parts of sulphate cf [ copper. The following are the ingredients: Sulphate of copper 41b Unslaked lime 51b Water 50gal The beet plan to prepare it is to make a stock solution of milk of lime and also of sulphate of copper solution. Th& sulphate of copper solution is made by dissolving ordinary bluestone in water. The eaeiest method is to dissolve 401b blueston© in a | 50gal cask, and then use 2igal to eaok i 50gal of wash. In cither case- the stock solution should be mad© up a day or two in advance, so as to void delay. It is only necessary to put the 401b into the 50gal cask, fill with water, and stir thoroughly | two or three times a day to bring into solution. Then slack carefully into a tubor wooden vessel 501b or lirno^; strain at once into a 50gal barrel, and fill with water, keeping th© barrels covered to prevent evaporation amd also to avoid trash getting into the solution, and they will hold good indefinitely. To prepare 50gal Bordeaux mixture, take sgal of the stock copper solution and dilute with 26gal water. In another vessel dilute sgal of tli9 lime pa^te with 20gal water. Then mix the two dilutions together, making 50gal. It is particularly important not to mix ih& lime and the copper solutions together until after diluting each of them separately in th© same : ; quantities of water; Do not pour tlie oop- ■ per solution into the lime or the lime into i the copjper, but pour the two together into | the 50gal cask, keeping the whole continuj ally stirred, so that -Ehe "irfgredients" shall ; blend in the most natural and equal way. The Bordeaux stays in suspension better ] when handled in this mannei than if mixed full strength and" the water added. Caution. — Iron vessels should not be used in preparing Bordeaux mixture. The uten- | sils best for the purpose, i* 1 addition to th© tw> 50gal barrels required for holding the ! two stock solutions, are a box for slaking the lime, Iwo half barrels of 25gal capacity for diluting the copper solution and the milk of lime separately, and a 50gal barrel for mixing together the two solutions. — Bordeaux Dust — may b© prepared by making a standard Bordeaux mixture, and allowing it to stand until the blue precipitate lias settled; th© clear wash ie then poured Gff, and the blue I precipitate thoroughly dried and ground between millstones to a fine powder. A similar article is offered in trade under various namesT Its use is still in th© experimental stage, and has not yet been definitely recommended. — Bordeaux Mixture and Arsenites — • may be combined, when it "is necessary to spray for combating codlin moths as well as for fungi. Paris Green or other ar=«r.ite may be added to ihis mixtui'e, as if it were water, and thus one fpraying will b© saved, but on no account add arsanites to ammoniacal carbonate of copj3'©r solution. — Formalin Sc-Htion. — Take formalin one pint. Take water 30gaI. This is a very useful remedy, used a? a preventive of potato scab. Before planting, soak t-Lie put.itces m Uio liqt f] for about three hours. At the rat© of commercial formalin, lib to 33gal water, or loz to l^gal or 2gal water, applied with sprinklw or drip attachment to drill upon 6cattered seeds, until moistened, then cover ing the seeds promptly ~>TJJh earth, is o-n-© of the best pr> ventives o{ 6K1&12-. & m u.t iv infected soils, l

— Sulphate of Iron and Sulphuric Acid Mixture. — Sulphate of iron, 2£lb. Sulphuric acid, ilb Boiling water, Jgal. Place the sulphate of iron in a wooden tub, and add the water; lastly, pour the acid carefully into the water, stir, and when the sulphate of iron is dissolved, it is ready for use. An excellent winter remedy for controlling black spot of the vine (anthraonose). Paint the vines aft&r pruning. (To be continued.)