4 BULLETIN" 924, U. S. DEPARTMENT OE AGRICULTURE. 
associated with rust-mite control is strong evidence that rust mites 
might be largely concerned in the causation of the condition that is 
generally recognized as wither-tip tear-stain. 
Table I. — Effect of various sprays on the control of tear-stain on grapefruit. 
Plat designation and spray application. 
Date. 
No. 1, 
Bordeaux 
mixture. 
No. 2, 
Burgundy 
mixture. 
No. 3, 
Bordeaux 
mixture. 
No. 4, 
lime- 
sulphur. 
No. 5, 
lime- 
sulphur. 
No. 6. 
1917. 
Jan. 29 
3-4-50 
3-4-50 
3-4-50 
3-4-50 
Not 
sprayed. 
70.39« 
3-34-50.... 
3-34-50.... 
3-34-50.... 
3-34-50.... 
Not 
sprayed. 
38.2 
3^-50 
1-40 
1-40 
1^0 
Not 
sprayed. 
do 
7.5 
1-40.... 
1-40.... 
1-40.... 
1-40.... 
1-66.... 
1.25 
Not sprayed. 
Do. 
Mar. 23 
3-4-50 
3-4-50 
Do. 
May 2 and 22 
Lime-sulphur, 
1-40. 
Lime-sulphur, 
1-66. 
1.3 
Do. 
June 
Lime-sulphur, 
1918. 
February (final count of 
1,000 fruits), tear- 
stained, per cent. 
1-66. 
25.9. 
a The excessive number of tear-stained fruits on the plat sprayed with Bordeaux mixture may be 
explained by the fact, quite frequently noted, that rust mites become unusually abundant on trees sprayed 
with that material. The injury did not resemble Bordeaux russet, but was similar in every respect to the 
tear staining on plat 6. 
A part of a grove of grapefruit was sprayed experimentally in June, 
1919, using 3-4-50 Bordeaux mixture for plat 1 and 1-66 lime-sulphur 
solution for plat 2. Plat 3 was an unsprayed check. This grove had 
not been sprayed previously that season. At the end of July the 
fruit in plat 2 was free from tear staining, but numerous tear-stained 
specimens were observed in plats 1 and 3. The fiuit on these plats 
ripened and was harvested in February, 1920, with no increase of tear- 
stain over that observed in July, 1919. This indicates that one appli- 
cation of weak lime-sulphur solution applied at a time suitable for 
rust-mite control in that grove was equally effective for the control 
of tear-stain, while the standard strength of Bordeaux mixture applied 
at the same time did not reduce this blemish. (PI. II, ng. 2.) 
Other experimental data obtained during the past four years 
show without exception similar results. 
The conclusion of Yothers (11), based on numerous extensive 
experiments to control rust mites in various parts of Florida, is 
that bright fruit — i. e., fruit free from rust-mite injury — is invariably 
free from tear-stain as well. (PL II, fig. 1.) 
Growers generally throughout the Florida citrus belt have accom- 
plished commercial control of tear-stain whenever they have con- 
trolled rust mites by following the spraying schedules established 
for these pests. 
Definite observations in commercial groves show clearly the 
following facts: (1) Where rust mites are naturally absent tear- 
stain is not observed; (2) where rust mites occur and are successfully 
controlled tear-stain is also controlled; (3) where rust mites are 
