[Vor. 3 
60 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
previous year was repeated, the relation between temperature 
and the attack was not as marked as it had been ір 1912. The 
higher temperatures were sustained for a longer time, and, 
therefore, the percentage of disease continued to rise through- 
out the summer. "The plants were set June 24, and no disease 
was found on July 4. Nevertheless, the main attack occurred 
in practically the same relation to the hottest weather as it 
had the previous year. 
In 1914 the plants were grown on two experimental plots, 
and in addition to the strains mentioned above, a resistant 
strain from the Maryland Agrieultural Experiment Station 
XXIV) was added. The plants were set on June 26, and 
the disease was first observed on July 16, when 1.5 per cent 
of the plants showed the typical yellowing. Tables rx and x 
summarize the observations that were made during this sum- 
mer. 
TABLE VIII 
SUMMARY OF FIELD OBSERVATIONS ON EXPERIMENTAL PLOT AT 
RACINE, WISCONSIN, 1913 
July 19 July 28 September 6 
Total 
Strain no. o 
plants | Number | Per cent | Number | Per cent | Number | Per cent 
yellow | yellow | yellow | yellow | yellow | yellow 
|) METER EUN 50 28 56.0 42 84.0 47 94.0 
ІШ АЖЕК ЛИР 46 28 60.8 34 73.9 34 73.¢ 
EEN 25 54.3 29 63.0 45 97.8 
VII (а-у)......| 1243 639 51.4 874 70.3 795 63.€ 
VIII (a & b)... 96 3 3.1 8 8.3 9 ).4 
IX (8-116). .... 248 77 31.0 120 48.4 98 39.5 
EE 19 40.4 21 44.7 33 70.2 
Eis 17 45.9 24 64.8 24 64. 
XIII (1-19). 820 301 36.7 489 59.6 748 91.0 
XIV (1-11)..... 565 140 24.7 256 45.3 504 ) 
Muysis 985 556 56.4 707 71.7 827 ) 
9,4, 4 Pas 1 25.6 25 58.1 42 m. 
зад MR 40 17 42.5 26 65.0 32 ( 
XM un w 28 19 67.8 20 71.4 26 ; 
P qi EE 42 5 35.7 17 40.5 12 у. 
ЖОҚ; UP 38 5 39.4 17 44.7 28 ).6 
ари 39 20 51.3 23 58.9 37 4.8 
EH toss 39 4 35.9 11 28.2 16 41.0 
XXIII 33 7 51.5 17 51.5 23 69.7 
Total,..... 4485 1961 44.3 2760 51.9 3380 63.5 
