THE FIELD TESTING OF COPPER-SPRAY COATINGS. 



had received a first application of the mixture about the middle of 

 June. The readings indicate the milligrams of copper per 100 grams 

 fresh weight of leaves. Two other orchards, C and D, in the same 

 locality, bore light crops of fruit and for this reason were given rather 

 light spraying of 3-4-50 Bordeaux mixture by their owners. 



Tests before and after the second and third spray applications in 

 these orchards gave the results shown in Table I. 



Table I.- 



-Field tests in spraying apple orchards A, B, C, and D vrith 3-4-50 Bordeaux 

 mixture, at Crozet, Va., in July and August, 1917. 





Orchard A. 



Orchard B. 



Orchard C. 



Orchard D. 



Spray application. 



Date 

 sampled. 



Reading. 



Date 

 sampled. 



Reading. 



Date 

 sampled. 



Reading. 



Date 

 sampled. 



Reading. 



First 



; July 9 

 \ July 12 



1 July 17 

 j July 19 

 1 July 23 

 I July 26 



August 2 



Milli- 

 grams. 

 41.6 

 29.4 



125 

 125 

 111.1 

 76.9 



100 



July 9 

 July 12 



Milli- 

 grams. 

 35.7 

 21.7 



July 19 



Milli- 

 grams. 

 41.6 



July 20 



Milli- 

 grams. 

 29.4 





July 23 

 July 26 



62.5 

 20 



July 24 

 July 26 



47.6 



Second 



July 20 

 July 24 

 July 26 



Aug. 2 



166.6 



125 



100 



125 



31 















Third 



Aug. 3 



55.5 



Aug. 2 



71.4 







BEARING GRAPEFRUIT TREES AT WINTER PARK, FLA. 



Two spray applications on a commercial basis were made on plats 

 of bearing grapefruit trees at Winter Park, Fla., the first on March 9 and 

 the second on April 16, 1918, using a power sprayer developing approxi- 

 mately 225 pounds pressure. The plats contained 30 trees each. 



•9 /& *?,P <5' /& ^'& S" /<P *?<S» 





Sl 



< 







1 



;: 



\^ 











n 











v-~~ 



/,X1 \ 











Vb- ■<>• 









V 



\ 



\ ''^-- 











Vv 

 \ 















^-^ 









b— 0..4 













p 



!FiG. 2. — Field tests for copper on grapefruit leaves sprayed with 3^-50 Bordeaux mixture {A), 3-4-50 

 Bordeaux mixture with the addition of a certain oil emulsion (B), 3-3^50 Burgundy mixture ( C). 

 Each apphcation was renewed on April 17. 



Single samples of 200 grams fresh weight were taken from each plat 

 at intervals of about four days luitil June 1 (fig. 2). In this test 

 3-4-50 Bordeaux mixture was used with and without a certain oil 



