Transactions of RHASS Volume 1940 - Page 031
Image details
| Year | 1940 |
|---|---|
| Transcription |
|
| OCR Text |
50 THE CONTROL OF PESTS 0F FARM AND GARDEN CROPS. lead arsenate with a little water and add to the tank shortly before spraying. Paris Gracia—This has been found a very eifective poison in baits for slugs, but it is now being diSplaced by Metaldehyde. It is still used as a poison for ‘grub,’ the caterpillar stage of the Crane Fly or Daddy Longlegs. For this purpose it is miXed with moist bran and spread over the infested ground. M ctaldehyde.—Metaldehyde is an organic chemical compound which has been used for many years as a solid fuel in picnic outfits. It is sold by most druggists and dealers in picnic goods under the name of Meta Fuel, and is available as such in all parts of the country. This Substance has been found to be very poisonous to slugs, snails and surface caterpillars, and makes a very efficient slug bait when mixed with bran. For use one stick of the fuel (about l oz. in weight) is ground to a fine powder and mixed with 2 oz. (or % pint) of bran. rl‘he bran is better moistened before mixing with the Meta. The mixture is scattered around the plants or laid in small heaps about one yard apart. P1 ccmztions.—Mcta is poisonous to all animals, and where fowls or other domestic animals may gain access to the bait it should be covered with a tile or a stone. FUNGICIDEs. There are two important groups of fungicides—namely, the sulphur group and the copper group. The most important members of the sulphur group are lime sulphur, sodium polysulphide, and sulphur; while in the copper group we have Bordeaux mixture, Burgundy mixture, Cheshunt com- pound, and copper naphthenate. In addition to the sulphur and copper fungicides various other substances such as mercury compounds, formalin, and tar acid preparations are used as fungicides. Certain organic mercury compounds are used in the form of dusts. Lima Sulphur.——Lime sulphur is the most important of the Sulphur sprays uSed in this country. It is an efficient contact poison for certain scale insects as well as an important fungicide for several fungoid diseases. When sulphur is combined chemically with calcium under certain conditions it forms calcium polysulphide, the principal active ingredient in lime sulphur. Formerly lime sulphur was prepared at home, but now there are so many good commercial brands available at reasonable cost that, unless the operator has expert chemical knowledge, home preparation is not worth while. Lime sulphur solution should be clear and free from sludge and have a specific gravity of approximately 1'3. It should contain not less than 185 per cent in weight of poly— THE CONTROL OF PESTS OF FARM AND GARDEN CROPS. 51 sulphide Sulphur. For all practical purposes the operator should test the specific gravity by means of a hydrometer. The concentrated solution should be kept tightly sealed because when it is exposed to the air it combines with oxygen, and the polysulphide undergoes decomposition. b The concentration of the Spray used varies with the season at the year. The amount of lime sulphur solution required to makch gallons of spray by diluting with water at different seasons is as follows : dormant season, 1 gallon ; early Spring 2.} pints ; mid-spring, 2 pints ; and late spring, 1% pints. , Lime sulphur may be mixed with nicotine sulphate and leartl arsenate for a general spray for both fungoid and insect DOS vS. Sodium P0lysylphida—There has appeared upon the market recently a sodium polysulphide solution. This solution is similar in properties to lime sulphur, but the makers claim that varietles of plants which are liable to be injured by lime sulphur are more resistant to the action of sodium polysulphide. Sulphur.—Flowers of sulphur was one of the first fungicides to be used,.but fell into disuse because of the difficulty of nnxmg it With water and gettinjz‘ it. Spread over the foliage .slethods have now become available whereby Sulphur may be made _to mix with water easily, and this wettable sulphur displacipg limehsulllpliur as a summer spray. Many sulphur- siy varieues, w 10 are in'ured b li affected by wettable sulphug. y me sulphur, are 11013 ‘Sulphur for this purpose must be in a very fine state of tlivision—agood sample should pass through a BOO-mesh sieve ll the particles are coarser than this they sink too easily to Hug bloilaltom of the bath when mixed with 'water. ‘11 p 111‘ may be made wettable With water b Sim l ' ' (r the sulphur with a wetting agent. One of tlie begtyigel’lftiflg agents for this purpose is soya bean flour, which is much used in Anicrica and which acts as a sticker as well as a wetter A good mixture of this kind is made by mixng 95 parts of sulphur with 5 parts of soya bean flour. 7 Another good-mixture for plants which are very susceptible to sulphur burning is made up as follows : sulphur 16 parts by weight ; slaked lime, 8 parts ; calcium caseinate 1 part——’ the wholebeing well mixed together. The inclusion, of slaked lune ll] this mixture reduces the danger of sulphur burning ' A wettable sulphur spray should contain 6 lb. of sulphur 111.100 gallons of water. Wettable sulphur may be combined With lead arsenate, nicotine sulphate, derris powder and bordeaux mixture in making general purpose sprays. A good general purpose spray can be prepared by mixing one (S): Efigtagpve wettablet sulphuf mixtures with derris powder t esra con a1ns6 . ' 100 gallons Ofpwéyter' b sulphur and 2 lb. derris to |
| Title | Transactions of RHASS Volume 1940 - Page 031 |
