CONCLUSIONS, CORVALLIS, OREG.. 



29 



Observations Continued . 



TABLE V. PLUMS, WITHOUT LIME. 

 [1 ounce to 15.5 gallons.] 



PLUMS (WITH LIME). 



Only three trees were spra}^ed with the solutions made up with 9.5 

 gallons of water, Nos. 2, 3, a and 4 being used. No effects from the 

 sprays were to be observed on either July 23 or August 3. OD 

 December 1 the first two were entirely defoliated, while the tree 

 treated with No. 4 had only lost a few leaves. 



A number of varieties were sprayed with the solutions Nos. 1 to 6, 

 made up with 15.5 gallons of water to an ounce of the green. None 

 of the trees showed any injury on either July 23 or August 3, but on 

 December 1 all were either completely, or almost completely, defoli 

 ated. A Reine Claude plum tree sprayed with No. 1 and a Green 

 Gage sprayed with No. 3 were among this group, with results as stated. 



DISCUSSION. 



The observations made on December 1 were for the purpose of find- 

 ing out whether the sprayed trees dropped their leaves earlier in the 

 fall than those not sprayed, and whether this premature falling, if it 

 existed, had any relation to the amount of soluble arsenious oxid used 

 on the tree. The time at which the leaves fall ordinarily varies greatly 

 with the season and the variety of the tree. The college orchard con- 

 sists of two or three trees each of quite a number of varieties, and 

 when they were examined, on December 1, there was not only a sur- 

 prising degree of variaflon in the condition of the foliage of the differ 

 ent varieties but also a great difference between the several trees of 

 the same variety. Two apple trees (Waxen) standing side by side 

 were sprayed with No. 2 plus lime. On December 1 only a few leaves 



a A cherry tree sprayed with No. 3 without the addition of lime showed no injury 

 on July 23 and August 3, and on December 1 it was entirely defoliated. 



