EXPERIMENT STATION REPORTS. 105 



green if there are canker worms or other leaf-eating insects in the 

 orchard. 



Copper Sulphate vs. Iron Sulphate. — Owing to the fact that sulphate 

 of iron is produced as a by-product in many manufacturing establish- 

 ments, and hence can be obtained at a comparatively low price, while 

 on the other hand an increased demand for copper sulphate has caused 

 it to advance from 100 to 150 per cent over the price charged for it 

 fifteen years ago, many fruit growers are inquiring if sulphate of iron 

 cannot be substituted for sulphate of copper. To test this question a 

 number of trees of each of the different classes of fruit were sprayed 

 with sulphate of iron during the spring and, later on, with iron- 

 Bordeaux mixture formed by substituting iron sulphate, or green 

 vitriol, for copper sulphate, or blue vitriol, in Bordeaux mixture. It 

 formed an excellent spraying material and coated the trees very thor- 

 oughly, giving them a dirty, brown appearance but, as the season ad- 

 vanced, it was evident that its value as a fungicide was much less than 

 that of the ordinary Bordeaux mixture. Apple and pear trees were 

 considerably injured by the scab fungus, and cherries and plums suf- 

 fered very seriously from the attack of brown rot, the injury being 

 nearly as great as where trees were left unsprayed, while trees of the 

 same varieties sprayed with Bordeaux mixture escaped with but slight 

 loss from the attack of fungi. Small quantities of copperas were also 

 used as a fertilizer upon the different kinds of trees, but no effect could 

 be detected either upon the growth of the trees, the color of the foliage, 

 or the amount of injury from fungi. Judging from this year's experi- 

 ence with sulphate of iron, it is not thought advisable to recommend 

 it either as a fungicide or a fertilizer, although its germicidal qualities 

 when used as a solution at the rate of five pounds in fifty gallons of 

 water, during the dormant period, upon trees and vines where the 

 spores winter upon the branches, may make it valuable for that purpose. 



August Spraying for the Codling Moth. — The use of Paris green for 

 the control of the codling moth was at first confined to one or two appli- 

 cations made within two or three weeks after the petals had fallen and 

 before the basins were closed by the calyx. This proved quite effective 

 for the destruction of the first brood, but it was known that a second 

 brood developed in August and, although entomologists claimed that 

 sprayings made after the middle of June would not be effective, it has 

 been found in actual practice that if an arsenite can be used at about 

 the time the second brood of larvae appear it will have a very marked 

 effect in rendering the fruit free from worms. However thoroughly the 

 trees may be sprayed in ]May and June some of the worms will certainly 

 escape and, especially if there are unsprayed orchards in the vicinity, 

 there will be a sufficient number of moths in August to provide eggs 

 for a large proportion of the fruit. By that time the early applica- 

 tions will have been washed off and, unless something is done to de- 

 stroy the second brood, serious loss may result to winter varieties. 



Experience has shown that one or two applications of an arsenite 

 during the first half of August will aid materially in saving the fruit. 

 From the fact that Paris green or arsenite of lime are readily washed 

 off, it has been found desirable to use arsenate of lead at this time, 

 especially • if only one application is made. This has greater adhesive 

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