ANTHRACNOSE OF CUCURBITS. ees 
tiveness and safety was used. This consisted of immersion in mercuric 
chlorid, 1 to 1,000, for 5 minutes, followed by 15 minutes’ washing in 
running water. This bulk seed treatment, involving the handling of 
400 pounds of seed,. was done at Madison. By this cooperative 
method very large amounts of seed were tested in separate districts 
under a variety of conditions. As in the tests at Madison, these tests 
aimed not only at a proof of the theory of the seed carriage of disease 
but at the same time aimed at disease control, as will be noted later. 
In Michigan anthracnose occurred in neither the 34 fields planted 
with untreated seed nor the 42 planted with treated seed, so 1t is ob- 
vious that there was no anthracnose in the lowa seed. The results 
obtained in Indiana and Wisconsin are briefly summarized in Table 
VIII. It is to be noted that due allowance has been made for the 
complicating factor of possible overwintering in the soil. 
TasLe VIII.—Effect of seed treatment wpon the occurrence of cucumber anthracnose, as 
shown by cooperative field tesis in Indiana and Wisconsin, season of 1917. 
Effect of seed treatment. Overwintering. 
; | Anthracnose Anthracnose 
Diseased not due to 1916 | 1746 Crop, same | “ due to 1916 
peas: crop. a crop.? 
State. Nii: 
Seed. ber of Per- Per- 
fields. cent- cent- 
Num- aig Num- hs Num- | age of | Num-| age 
ber. Dies ber. ane ber. dis- ber. of dis- 
8e. ge. eased eased 
fields. fields. 
‘ Untreated.... 30 15 50 4 1S 3o3 9 60 11 13583 
Indiana.....- Treated ...... 42 A GES Oyen TA is al 71 100 
: ; Untreated.... 43 2 4.7 1 2.3 0 0 1 50 
Wisconsin..../\Treated...... 33 Tan peal 1|; 3.3 21 60 Salk mrs 
Total Untreated... . 73 ile 23.3 5 6.8 9 52.9 12 70.6 
y ws\\'Treated....:- Go iO 14.6 1 1.3 6 54.5 10 90.9 
(GES alain) fll enor Sone tibiae ie Meena ere te aa ee Siar eats eke ee 555 
due to 
treat- 
ment. 
1 1916 crop not on same or neighboring field. 2 1916 crop on same or neighboring field. 
The results show that there was apparently very little anthracnose 
in the Ohio seed, since most of the cases of anthracnose occurrence 
may be attributed to overwintering. Among the very few cases in 
which anthracnose could not be due to the previous crop, the Wisconsin. 
trials are inconclusive, while the Indiana tests indicate that anthrac- 
nose may have been introduced with the seed. 
From the standpoint of the introduction of the disease with the 
seed, all of these seed-disinfection, tests, while inconclusive, indicate 
that anthracnose may be carried with the seed, and they show the 
need of further tests of this nature. 
