236 HELMINTHOSPORIUM SPP. ON CEREALS AND SUGARCANE IN INDIA 
maize Helminthosporium the colour is light greyish green but here it is dark greyish green and 
moreover aerial growth is absent. After some time little aerial growth appears but still the 
growth is darker than that of maize. -Spore and mycelium resemble somewhat maize 
Helminthosporium. About 50 per cent. of jowar spores resembles the maize fungus but the 
remaining spore percentage is somewhat broader.. The number of septa is the same in both. 
4. Jowar-meal agar. There is a creeping and submerged growth of light greenish colour 
at 30°C., and crowded and compact at 22°C. The colour of medium becomes similar to maize 
fungus but afterwards it becomes dark green. After 10 or 12 days little aerial growth of dark 
greyish green colour appears. Spore formation is good. 
5. Litmus lactose agar. The growth is poor and dark and greyish green, submerged and 
creeping in the beginning. The submerged portion becomes dark. Later on a little aerial 
growth appears. The growth on this medium is exactly like that of maize Helminthosporium 
onit. Spores are 45°6 to 95 by 15-2 to 22-8 in diameter. The spores and mycelium resemble 
maize Helminthosporium on this medium, the size, form and colour being alike. 
6. Coon’s synthetic agar. Fairly good at 30-32°C. of dark green colour. The growth 
resembles to some extent maize Helminthosporium on this medium. The fungus is more dark 
green at 22°C. Spore formation poor and the old mycelium becomes gemmate. The mycelium 
is darker than that of maize Helminthosporium. 
7. Corn-meal agar. Growth dark greyish green at 22°C., and light at 32°C. Submerged 
growth is greenish and there is no aerial growth Later on little aerial growth appears which 
is very much like that of maize and of greenish grey colour. The mycelium and spores resemble 
those of maize Helminthosporium. After 10 or 12 days maize and jowar cultures resemble very 
much on this medium. Spores and mycelium almost alike and spore formation more at a 
low temperature of 20 to 22°C. than at 30-382°C. Spores are 80°5 to 122°5 by 15°8 to 21 in 
diameter while those of maize Helminthosporium are 77 to 122 by 15:8 to 19y. 
8. Oat-meal agar. Dark creeping growth at both temperatures but little more at 32°C, 
After some days growth appears dark greyish green, creeping and submerged. Spore formation 
is good. The mycelium resembles that of maize Helminthosporium. On this medium the 
aerial growth is comparatively smaller. 
9. Nutrient saccharose agar. Creeping and submerged growth of dark grey colour with 
little aerial growth and poor spore formation. 
10. Thaxter’s hard potato agar. Dark green, submerged and creeping, resembling the 
growth of maize Helminthosporium but there is no aerial growth. After some time little aerial 
growth appears. Spore formation resembles that of Helminthosporium on maize. 
11. Wheat straw. Wheat straw was sterilized in ordinary tubes containing little water, 
The fungus was grown on it and the tubes were kept at 27-30°C., and some at 22°C. There 
was a good production of spores on it. The growth was like that of maize, but in the latter 
case more spores were formed. In these, there was no good aerial growth. Greyish green 
mycelium was formed at the bottom of the tube in water. 
From the results of inoculation experiments and from cultural characters 
this fungus appears to be very closely related to or identical with Helminthos- 
portum on maize, but the fact that in one place it occurs on one host and net 
on the other, makes one to consider them as two different varieties of H. turcicum 
Pass. 
CROSS-INOCULATION EXPERIMENTS. 
The following cross-inoculations were made with jowar Helminthosporium 
on the same hosts on which maize Helminthosporium was inoculated and in 
the same manner, 
