19, 2 
Lee: Citrus-canker Control 
139 
It can be seen from this tabulation, that the amount of canker 
in this plat at the end of the experiment in August, 1918, was 
quite as great as it was in August, 1917, when the work was 
undertaken. The criticism may be raised that the estimation of 
the amounts of foliage cankered could not be accurate. This 
is, of course, a valid criticism, but no other method of measuring 
the amounts of canker was available in as much as few or no 
fruits were formed in the orchard during this season. The 
amounts of canker were determined only after long and careful 
examination and, in the case of the affected leaves expressed 
numerically, is from actual count. 
PLAT III, AT LOS BANOS 
The treatment of this plat was as follows : 
August 24, 1917. Cresol-kerosene emulsion, plus mercuric bichloride 
to make a 1 to 1,500 solution. 
September 14, 1917. Burgundy 3-31-50 mixture. 
October 11, 1917. Burgundy 3-31-50 mixture. 
November 12, 1917. Burgundy 3-31-50 mixture, plus powdered 
neutral lead arsenate to make a 1-50 mixture. 
December 20, 1917. Burgundy 3-3-50 mixture. 
January 5, 1918. Yothers’s oil emulsion. 
May 17, 1918. Neutral Burgundy mixture, plus formalin 1-100. 
June 14, 1918. Neutral Burgundy mixture, plus formalin 1-100 and 
cresol-kerosene emulsion. 
July 13, 1918. Neutral Burgundy mixture. 
Table 6. — Showing degree of canker affection of trees in Plat III of the 
College of Agriculture citrus planting at Los Banos. 
Species. 
Leaves affected. 
August, 1917. 
August, 1918. 
Per cent. 
Number. 
Per cent. 
Number. 
Citrus maxima 
3 
0 
0 
Do 
1 
1 
Do 
10 
1 
10 
2 
Do 
8 
0 
0 
Do 
1 
0 
0 
Do.__ 
0 
0 
0 
0 
Do 
10 
12 
Do 
0 
0 
4 
Do 
20 
0 
0 
Do 
5 
0 
0 
Citrus mitis 
0 
0 
0 
0 
Do 
0 
0 
0 
0 
Do-~ 
2 
0 
0 
Do 
5 
0 
0 
Citrus limonia 
5 
2 
Do__ 
1 
10 
