u 



leum emulsion. Similar photographs could be shown in the case of 25 

 per cent mechanical emulsions of both kerosene and crude petroleum. 

 But when we come to examine the results obtained with the undiluted 

 oils, even after making allowance for scale injury, one can not resist 

 the conclusion that both kerosene and crude petroleum may cause 

 serious harm. Pure kerosene was considered by the owner of the 

 orchard as dangerous material to use on a tree, and on that account 

 but three trees were sprayed with it and all of them were in very bad 

 condition from scale attack. The Howell pear tree No. 21 was sprayed 

 April 11, photographed May 14, and was quite badly infested with 

 the scale. At this latter date most of the tips of the limbs showed 

 few leaves, and there were very few blossoms. The tree had evi- 

 dently suffered considerably from the scale, and it is probable that the 

 kerosene also injured it. June 20 the foliage of this tree had devel- 

 oped considerably, and while there were a number of dead branches, 

 the suckers thrown out may eventually fill the vacant places. 



It is with the crude petroleum, however, that the most marked 

 results were obtained. The seckel pear, No. 101, was photographed 

 May 12 and shows well the very few undersized, pale leaves. June 20 

 there were onl}^ a few bunches of leaves on four limbs, and a number 

 of adventitious buds were developing. The foliage at this time was 

 light in color. This tree was badly infested with San Jose scale, but, 

 making due allowance for that, it is still far from what it should be. 

 The Lombard plum tree. No. 93, was photographed May 12 and shows 

 very well the effects of a spring application of crude petroleum. This 

 tree was but moderately infested with the scale, and consequently 

 most of the injury can be charged to the treatment. Only the stronger 

 buds near the tips of the branches stood the test well. Many of those 

 on the side branches were killed and others much weakened. The 

 28th of May I made the following note concerning this tree: " Leaves 

 out considerably, but the folliage is still much thinner than on other 

 trees of its kind." June 20 it was still seen that the foliage was thinner 

 than the normal. The next tree, a Botan plum, was apparently in the 

 same condition as No. 93 at the time of spraying, but on May 28 there 

 was just one weak leaf, and a few of the apparently dead twigs showed 

 a little green beneath the bark. Later the owner dug the tree out as 

 dead. 



Applications by horticulturists or farmers are worth}^ of close atten- 

 tion, because they are made more nearly under usual conditions. I was 

 therefore very glad to avail myself of the opportunity of watching 

 closely the results obtained b}" one. The extensive and abundant 

 infestation of his young orchard with the San Jose scale led Mr. L. L. 

 Morrell, of Kinderhook, N. Y., to try crude petroleum. Some young 

 tree tops worked with Sutton Beauty were sprayed April 1 with 25 per 

 cent mechanical mixture of crude petroleum, the trunks having been 



