THE FIELD TESTING OF COPPER-SPRAY COATINGS. 5 
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. 
TasLe |.—Field tests in spraying apple orchards A, B, C, and D with 3-4-50 Bordeaux 
mixture, at Crozet, Va., in July and August, 1917. 
Orchard A. Orchard B. Orchard C. Orchard D. 
Spray application. 
Date . Date : Date . Date : 
sampled. Reading. sampled. Reading. sampled. Reading. sampled. Reading. 
Milli- Milli- Milli- Milli- 
grams. grams, grams, grams 
First July 9 41.6| July 9 35.7 | July. 19 41.6 | July 20 29.4 
TS to SCS Oro ea July 12 29.4| July 12 PU (eh Weep, samp yetN Ka Mangus «AN Ag ge Nm As 
July 17 Se Ri Aye ene EL. ROR July 23 62.5 | July 24 47.6 
Second July 19 125 July 20 166.6 | July 26 20 July 26 31 
BOL oon Bede Saar July 23 111.1] July 24 at ees SO POPU Ane Pee reat FUNG a 8 
July 26 76.9 | July 26 MODS ie | eee taR etc ye OS AAR OIE A ear (Reena 
Thin sesenss asec ee August 2 100 Aug. 2 125 Aug, 3 DOs0) | AUIS. 22 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. 
SVIOCLS LVL LA 
Xs) 79 29 o SE 29 S SP oP 
TO 
fog 
Q 
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ZO Sy 
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df . \ 
GO ‘ 
re ea 
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LULL CYRWIS OF CORAL? YL /OO0 
CRVWES SALSA MMIC] OF LLAVES 
Fig. 2.—Field tests for copper on grapefruit leaves sprayed with 34-50 Bordeaux mixture (4), 3-4+-50 
Bordeaux mixture with the addition of a certain oil emulsion (B), 3-33-50 Burgundy mixture ((C). 
Each application was renewed on April 17. 
Single samples of 200 grams fresh weight were taken from each plat 
at intervals of about four days until June 1 (fig. 2). In this test 
3-4-50 Bordeaux mixture was used with and without a certain oil 
