EXPERIMENT STATION REPORT. 647 



from the trees up until blossoming time in the spring. If used 

 in hot weather it will defoliate the trees, and we do not recom- 

 mend it for summer work.'' 



After a preliminary test I ordered 10 gallons of the material 

 sent to the Marsh orchard, retaining the sample for use in the 

 Experiment Orchard. The price of the material is $1.25 per 

 gallon, which when diluted by 20 parts of water, will bring the 

 cost of I gallon of diluted mixtures to 6^4 cents per gallon, 

 exclusive of the cost of transportation and application. 



The percentage of actual oil in the material when diluted was 

 so low that I decided to make use of it at the rate of i to 20 of 

 water, in an attempt to control the late fall developm.ent of the 

 scale. 



Applications were made under my direct supervision in the 

 Experiment Orchard, and at my direction in the Marsh orchards, 

 by Harold O. Marsh. In each case the applications were made 

 in October, and on trees that had been ineffectively treated with 

 other miaterials during the summer. In the Marsh orchard 

 peach trees only were treated ; in the Experiment Orchard, 

 plum, apple, pear and peach, 14 trees. In all cases ihere was a 

 more or less obvious mottling, discoloring or scalding of the 

 foliage ; but that did not, in any instance, amount to a 'material 

 injury to the tree. In every case the effect upon the scale was 

 marked. Larv?e and recent sets were wiped out of existence at 

 once, wherever the material reached them. Breeding adults 

 were killed in most cases ; but apparently adults that were ready 

 to reproduce but had not yet begun, escaped in many cases. So, 

 it is probable that some of the half grown black scales were suf- 

 ficiently resistant to protect the insects beneath them. Unlike 

 the other materials used, this exerts a continuous action for some 

 time, the resin perhaps holding it in contact with the insects 

 and giving opportunity to penetrate. 



The time during which the material has been kept under ob- 

 servation is not sufficiently long to authorize a final determina- 

 tion ; but certainly we have come nearer to a preparation of 

 petroleum which may be diluted with water, and it offers the 

 best chance of a satisfactory effect of any of the preparations 

 now on the market — though at a somewhat unreasonably high 

 cost. 



PYROL TREE AND PLANT SPRAY. 



This is in the nature of a pine tar preparation, mrnuifactured 



