brit. 
TABLE 7.--Number of trees sold from one experimental plot during the two winters, 
1936-37 and 1937-38, (Plot IXS) 
Percentage 
of Trees 
Sold 
Number 
of Trees Trees Sold 
Originally 
Present 1936-37 1937-38 Total 
226: 10 14 24 
250 22 26 48 
217 3 30 33 
200 3 24 27 
* 
Sprayed for seven seasons; pruned only the last four seasons. 
Treatment 
Urmemeecod « « 6 « sm «| a8 
Pruning (four years). 
Koloforn. . e e e ° e e ° e 
Koloform and pruning” 
RESULTS 
A recapitulation of the data presented in preceding pages is given in table 8, 
for direct comparison of the results obtained with the various treatments and combina- 
tion of treatments. 
These data indicate, as have the data in previous reports, that more than half of 
the different treatments tested have some value. The effective treatments, indicated 
by "#" signs in the table, range from.g per cent to 92 per cent in their degree of 
effectiveness, and several~—those effective to 30 per cent or more--are of practical 
value. As has been pointed out in previous reports, both ineffective and effective 
treatments for wilt control leaf diseases and stimulate tree growth. 
The average percentages of control or lack of control shown in the last column of 
Table 8 are compared diagramatically in fig. 1. The bars reaching to the right of the 
vertical line represent effective treatments, those to the left represent ineffective 
treatments and the bar-lengths indicate degrees of effectiveness or ineffectiveness. 
From fig. 1 and from table 8, it may be seen that the treatments that have been 
effective in the control of disease are (1) pruning, (2) instant Bordeaux in combina- 
tion with prming, (3) Koloform, (4) Koloform in combination with pruning, (5) "Mike" 
sulfur spray, (6) "Mike" sulfur spray in combination with pruning, (7) Kolodust, (8) 
Kolodust in combination with pruning, (9) flotation sulfur dust and "Mike" sulfur and 
(10) flotation sulfur dust and "Mike" sulfur in combination with pruning. The ineffec— 
tive treatments are (1) commercial Bordeaux, (2) instant Bordeaux, (3) Z-0, (4) Z-0 
in combination with pruning, (5) dry wettable flotation sulfur, (6) dormant and summer 
sulfur sprays and (7) dormant and sumrer sulfur sprays in combination with pruning. 
It is shown in this report, as in previous reports, that most of the effective 
treatments involve either pruning or sulfur dusting. In addition, this report shows 
that two other treatments are effective, namely, spraying with Koloform and spraying 
with "Mike" sulfur. 
Pruning, in most experiments, has shown a beneficial effect. But our experimental 
work has demonstrated that pruning does not always prevent the further development of 
disease. When, however, all diseased and discolored wood was removed, further progress 
of disease did not become evident for two or more years. In the trees in which disease 
recurred, it appeared that reinfection had taken place and that the disease was not a 
continuation of the original infection. In most of the pruned trees from which all of 
the discolored wood was not removed, disease continued to develop year after year. 
Pruning, when used in combination with instant Bordeaux, Koloform and the sulfur dusts, 
consistently increased the effectiveness of these treatments. 
15 
