1902.] DISEASES AND INSECTS, ETC. I4I 



In combating the scab, leaf blight, leaf spot, and canker 

 disease of the pear with the Bordeaux mixture an arsenical 

 poison may be used at the same time for the codling moth 

 and leaf-eating insects in general. In spraying the apple for 

 the codling moth, and also for the bud moth, case bearer, 

 canker worm, tent caterpillar, and various other leaf-eating in- 

 sects, the Bordeaux mixture may be used at the same time for 

 the scab, canker disease, and leaf spot. 



We have not yet spoken of the strength at which either the 

 fungicides or the insecticides are to be used. As might 

 naturally be expected, their strength, and also the number of 

 applications, may be varied to meet the necessities of the par- 

 ticular case in hand. Particular directions on these points 

 may be found in publications of experiment stations, and 

 of the United States Department of Agriculture. For most 

 orchard diseases which are amenable to treatment with the 

 Bordeaux mixture, this preparation, if properly applied, is 

 efficient, even when made as weak as one pound of copper sul- 

 phate to eleven gallons of the mixture. This is called the 

 one-to-eleven formula. It has been found that it is not best 

 to use it weaker than this for orchard diseases. Some prefer 

 a mixture as strong as one to eight. In treating the potato 

 blight the one-to-eight, or even the one-to-seven formula is 

 recommended. Paris green may generally be used success- 

 fully on foliage at the rate of one pound to one hundred and 

 fifty gallons of water, or of Bordeaux mixture. It is often 

 used stronger than this, but it is then more liable to injure 

 the foliage, and perhaps in this way do more harm than good. 

 Except when it is combined with the Bordeaux mixture it is 

 best to add lime to prevent injury to the foliage. The fact is, 

 though, that in cases of emergency it is often used as strong, 

 as, for example, where early treatment for the canker worm has 

 been neglected, orchardists have used it as strong as one pound 

 to one hundred gallons, and even stronger than that. There is 

 danger, however, in using it so strong of doing injury. And 

 it should be remembered in this connection that the foliage 

 of stone fruit trees is more susceptible to injury from arsenical 

 insectitudes than that of the apple, pear, or quince. Peach 

 foliage is especially liable to injury from spraying mixtures. 

 Even with Bordeaux mixture, which would do no injury on 

 apple trees, it will be very liable to injure the peach tree. I 



