SAVING OF FOLIAGE. 



81 



Tablk <i. — Comparative percentage of <llseuse(l foliage ou s/jraijed and unsprai/til Irees 



April 22 and 23 and May 9, 1895. 



Trees examined. 



Mnv 9, 



1.S95. 



Avcrnpp per cent of disenso on tlic trees of nil control rows 



AvcniKc i>cr cent of disease on the trees of all sprayed rows 



Average i)er cent of disease on the trees of the three rows sprayed in ISiM. but 

 left unsprayed in 1895 ! 



86.9 

 21.2 



87.0 



Those compaiMson.s show 3,8 per cent more di.seased foliage on the 

 control trees May '.♦ than April ±2. The percentag^e of foliage of the 

 sprayed trees showino- disease had decreased, however, 5 per cent. Of 

 the total foliage of the trees sprayed in ISiH. ])ut left unsprayed in 

 1805, 5 per cent more was di.seascd at the second date than at the first. 

 Thesr figures indicate that the divergence in the percentage of di.sease 

 on spra3^ed and unsprayed trees was still iiurt^asing just prior to the 

 second estimate. The second estimate may thus be considered as taken 

 before any of the trees had b(>gun to recover from the effects of the 

 disease. The time of maximum contrast was the true time to make 

 the estimates, and it is believed tlu' date of this second estimate was 

 certainly not too late to fully comply witii this rec^uirement. This 

 belief was suhstantiated by a third ptirtial estimate made a week later, 

 which gave in general very simihir results to those obtained May 9. 

 It should also be said that the decrease in the percentage of disease on 

 the sprayed trees between the dates of the first and second estimates 

 did not indicate that the second estimate was made too late, or after 

 the trees had begun to recover, but merely that th(» leaf buds had not 

 fully pushed at the time of the first estimate. This is further shown 

 by the fact that the percentage of disease was still increasing on 

 unsprayed trees up to that time. 



Before considering the action of individual sprays in saving the 

 foliage from curl, the following comparisons are given of the action 

 of the classes of sprays used: 



Table 7. — Percentage of healihy foliage on trees differently sprayed. 



60^ i 



I'ercentagcs of healthy foliage shown by trees sprayed with 

 different classes of sprays. Estimated April 23 and May 

 9, 1895. 



Average of 30 trees sprayed with sulphur, lime, and .salt 



Average of 70 trees sprayed with sulphur and lime 



Average of 100 trees sprayed with the two preceding sulphur 

 sprays 



Average of 90 trees sprayed with Bordeaux mixture 



Average of 20 trees sprayed with eau celeste 



Average of 20 trees sprayed with modified eau celeste 



Average of 130 trees sprayed with the three preceding copper 

 sprays 



Average of 20 trees sprayed with ammonlacal copper car- 

 bonate 



19093— No. 20 6 



