5T8 XEW JERSEY AGRICULTURAL COLLEGE 



into cfmsideratidii, nnd in tlio casp of the oils tlie actual amount of 

 raw material \isecl, i. c, the oil, should be the basis of comparison. 

 Por example, one man may spray with a mixture containing 20 

 per cent, of oil and another may use one containing 15 per cent, 

 only, and yet the man who uses the weaker mixture may get moro 

 iictual oil on his trees in a drench than the other may get with a 

 more sparing use, each giving a complete covering to the tree. 



Conolasions and Reoonvmendations. 



It is a fair conclusion, from what has been said above and from 

 the observations rccordc<l under the insecticide headings, that any 

 well-made lime and sulphur combination, with or without salt, and 

 any of the well-tested soluble petroleums, will kill all the scales 

 that are actually reaclu^d (U* covered by them. It is further ap- 

 parent that no one applicatit)u can be relied upon to do entirely 

 satisfactory work, ajid that the reason for that is mechanical rather 

 than lack of efficiency in llu^ insecticide. Xone of the materials or 

 jnixtures, undiluted crude oil excepted, will j^enetrate through a 

 dense mass of scales or into all crevices so as to reach all the insectxS 

 on a badly-infested tree, and none of them kill unless they come 

 into actual contact with the insects. The soluble oils, at 1 to 20, 

 contain so small a percentage of actual oil that a very thorough 

 ti})plication is necessary to reach all the insects with enough to be 

 entirely effective. 



The insecticides at our command are sufficient to control the 

 scale, and the remaining part of the problem is the mechanical one 

 of placing them where they can get a chance to act. 



Based upon all the observations and upon these conclusions, 

 peach growers arc^ a<lvised to use the lime and sulphur combina- 

 tions, because they \\a\c a fungicidal effect as well, and because 

 they seem to act as a general tonic to such trees. Where the trees 

 are only a little infested, either a fall or a spring application may 

 be made. A fall aitplicatimi will b(> sduiewhat more reliable to 

 obtain the greatest insecticide effect ; the spring apidication seems 

 to give better results againsr troubles due to parasitic plant dis- 

 eases. P)adly-infested trees should be s]u-ayed twice. 



Apples and pciirs are better s})rayed both fall and spring, what- 

 ever the mixture used, and on a])i)les 1 would reconunend the solu- 



