EXPERIMENT STATION WORK WITH INSECTICIDES. 247 



on untreated plum trees. Otherwise there was very litth' difference 

 between the two sets of trees. 



In another orchard which was infested with scale the plums lost 

 from 10 to 50 per cent of their flowers after treatment and showed 

 sli<j;ht injuries to the leaf buds, es}K'cially upon the lower branches. 

 Cherries suti'ere<l a loss of a per cent of the blossoms, apjjles and pears 

 beini^ similarly affected. In the third orchard, likewise infested with 

 the scale, no a])parent reduction in the numi)er of blossoms or leaves 

 was observed as a result of treatment with lime-sulphur sprays. The 

 California wash with or without salt and self-boiled or l)oiled with 

 heat was in all cases effective in destroying the scale. The addition of 

 salt did not increase the effectiveness of the wash. In recent experi- 

 ments by the New York State Station it appears that one applicatiori 

 of the sulj)hur wash was sufficient to reduce the amount of apple scab 

 22 per cent. A coml)ined treatment consisting of one application of a 

 sulphur wash before blossoming and two applications of the Bor- 

 deaux-arsenical mixture after blossoming reduces the injury from 

 apple scab and codling moth to the same extent as is observed after 

 the usual three applications of Bordeaux-arsenical mixture for these 

 pests. The j)ear-leaf blister-mite was eflfectively controlled by one 

 ajjplication of the sulphur wash before blossoming. These results, 

 combined with those obtained in New York and elsewhere, showing 

 considerable fungicidal value of the sulphur washes, indicate the 

 wide usefulness of this ])reparation. 



In Ohio" a test was nuide to determine the value of California and 

 Oregon washes when applied in the fall and also in the spring. The 

 California wash was completely effective in desti'oying the San Jose 

 scale when aj^plied in the fall, and was not injurious in any way to 

 peaches or ])lums. The wash appeared to prevent to a considerable 

 extent the development of leaf curl, but had little effect on brown rot 

 or shot-hole fungus. The formula used for the California wash in 

 these experiments was 15-15-1 o-oO, and the whole mixture was boiled 

 for one hour. The applications were made from November 2() to 

 December 15. The (Oregon wash, prepared according to the same 

 fonnula with the substitution of H pounds cop[)er sulphate for the 

 salt, was sprayed on i^each and })lum trees at the same time. This 

 te,st demonstrated that the Oregon wash is a perfectly safe and reli- 

 ai)le remedy for San Jose scale, but shows no pi-actical advantage 

 (»V( r the California wusli. A\'hen caustic soda was substituted for 

 part of the lime in making a self-boiled mixture the resulting insecti- 

 cide was niuch less effective. 



In Tennessee'' cherry, peach, plum, pear, and apple trees were 

 sprayed about the middle of March with California wash according 



"Ohio St:i. Rul. 144. 



6 Tennessee Sta. I'.nl.. Vol. XVI, No. 2. 



