30 
BULLETIN 1474, U. S. DEPARTMENT OE AGRICULTURE 
block of trees was pruned. Another block was pruned in February, 
and still another block in March, and so on throughout August of 
that year. 
The following year, 1922, pruning experiments were repeated. A 
part of each 1921 plot was repruned, and an additional plot was 
pruned for the first time in 1922. Pruning experiments were again 
repeated in 1923. That year the test was made in the same grove used 
in the two preceding years and on trees of a similar character but 
unpruned within the last six or eight years. They had possibly some- 
what less deadwood in them than had those used in previous years. 
At the end of each season 1,000 or more fruits from each pruned 
plot were graded for melanose infection, and for comparison many 
counts were made of fruit from unpruned trees. 
The results as shown in the fruit crops of the second (1922) and 
third (1923) year are given in Table 5. The first year's results were 
essentially the same as those of the second. 
Table 5. — Results of pruning experiments for citrus melanose control in a 
seedling orange grove at Orlando, Fla., in 1922 and 1923 
Date pruned 
Melanose infection 
Ab- 
sent 
Very- 
slight 
Slight 
Me- 
dium 
Severe 
Very 
COUNTED IN 1922 
Jan. 15 to 20, 1921; Apr. 6 to 8, 1922.... 
Feb. 15 to 20, 1921; May 8 to 9, 1922... 
Mar. 15 to 20, 1921; June 8 to 10, 1922.. 
Apr. 20 to 26, 1921; July 10 to 12, 1922. 
May 26 to 30, 1921; Aug. 10 to 12, 1922. 
June 20 to 26, 1921; Sept. 11 to 12, 1922 
July 18 to 22, 1921; Oct. 10 to 12, 1922.. 
Jan. 15 to 20, 1921 
Feb. 15 to 20, 1921 
Mar. 15 to 20, 1921 
Apr. 20 to 26, 1921 
May 26 to 30, 1921 
June 20 to 26, 1921 
July 18 to 22, 1921 
Aug. 23 to 24, 1921 
Apr. 6 to 8, 1922 
May 8 to 9, 1922 
June 8 to 10, 1922 
July 10 to 12, 1922 
Aug. 10 to 12, 1922 
Sept. 11 to 12, 1922 
Oct. 10 to 12, 1922 
Average of unpruned checks 
COUNTED IN 1923 
March, 1923 
April, 1923 
May, 1923 .' 
June, 1923 
Average of unpruned checks 
Per cent 























Per cent 
3 


1 
1 
3 
6 



7 
4 
9 
10 
14 
1 

1 
1 
2 
2 

Per cent 
9 
1 
1 
1 
19 
33 
31 
5 
6 
12 
26 
38 
31 
29 
18 
7 
3 
5 
4 
25 
15 
12 
16 
Per cent 
32 
26 
17 
25 
29 
42 
38 
38 
35 
22 
23 
34 
31 
35 
30 
15 
17 
35 
18 
40 
42 
38 
22 
Per cent 
26 
37 
45 
46 
34 
21 
. 22 
31 
39 
25 
32 
23 
24 
21 
28 
45 
52 
33 
53 
30 
39 
42 
37 
Per cent 
30 
36 
37 
27 
17 
1 
3 
26 
20 
41 
12 
1 
5 
5 
10 
32 
28 
20 
24 
3 
2 
8 
17 
For three consecutive years priming failed to have any appreciable 
effect upon melanose outbreaks on seedling oranges in these experi- 
mental plots. The slight differences in results obtained are due per- 
haps more to the general condition of the trees than to the efficacy 
of pruning as a means of controlling melanose. From these tests it 
is evident that the removal with reasonable care of dead and weak- 
ened parts can not be regarded as a dependable method for melanose 
