SEEDLING BLIGHT AND STACK-BURN OF RICE. - 7 
the hot-water treatments, tests were made to determine the per- 
centages of rice carrying these fungi internally. The kernels were 
carefully dehulled, treated 3 to 5 minutes in 50 to 70 per cent alcohol, 
then soaked for 10 minutes in a 1 to 1,000 solution of mercuric chlorid, 
and placed in tubes of sterile agar (Pl. IV) or on sterile agar or 
blotter paper in Petri dishes (Pl. VI) after washing thoroughly in 
sterile water. The results of these tests are given in Table 1. 
_ TaBLEe 1.—Jnternal infection of rice seeds after surface sterilization in crop varieties grown 
at Crowley, La., in 1919. 

Seeds infected. Seeds infected. 


eae Seeds ate a rat ge Seeds 
Variety. treated. Variety. treated. 
| Number.| Per cent. Number. | Per cent. 
Honduras.......... 261 | 197 75.48 || Carolina White..... 48 46 95. 84 
Wiatariboness=) 2. : 60 42 | 70:00) i Shinrika®: 222-2 Le 48 32 66. 66 

The rice for the tests referred to in Table 1 was taken from the 
stock seed supply at the Rice Experiment Station, Crowley, La., in 
the fall of 1919, and the tests were made during the following winter. 
During the spring of 1920 seeds from a larger number of the best 
varieties of rice were tested to determine their relative susceptibility 
to internal seed infection. Of each variety obtained from the seed 
lots at the Crowley rice station 100 seeds were dehulled and their 
surfaces sterilized; then they were washed thoroughly in sterile water 
and placed in sterile moist chambers on damp filter paper. They 
were allowed to incubate at room temperature for seven days, and 
the percentages of germination and infection were then taken. No 
attempts were made to identify the fungi from each kernel. The 
results of these tests are given in Table 2. 
TABLE 2.—Germination and internal infection of rice seeds grown at Crowley, La., in 1919, 



Germi- Germi- 



ese Infection. aatioil Infection. 
Variety. Variety. ; 
Per Per Per Per 
cent. | cent. | Pestee cent. | cent. | Pegtee. 
Delitus (large shocks). ... 86 50 | Slight. IRGKA ONE Se satie ee oe a 84 38 | Slight. 
Delitus (small shocks).... 64 79 | Heavy. || Evangeline..............- 50 95 | Heavy. 
ee eee 92 41 | Slight. INCROIR ST pee te oes 81 65 | Slight. 
Shri oa ee 2 eT 99 35 Do. Barly rowne ss 6S. 05. 66 49 
EIGIGIEAS © yf Le: 53 83 | Heavy. || Honduras (California)... . 99 9 Do. 
Wiataribune: - 22. .-... -< 92 25 | Slight. Wataribune (California). . 98 | ff Do. 
Carolina Gold............ 83 91 | Heavy. || Early Prolific (Louisiana) 69 | 70 | Heavy. 
perTIN MG SS sae. 2... 63 92 Do. Honduras (California). -.. 99 | 25 | Slight. 
SS a aes pai 95 38 | Slight. Wataribune (California)... 98 8 Do. 



In Table 2 the Delitus variety was obtained from both large and 
small shocks. The harvest season was a very wet one, so the grain 
in the small shock was injured much more than that in the large or 
normal shock. The terms ‘“‘slight”’ and “heavy,” referring to the 
