M. MITRA 229 
the amount of moisture in the air and may take place after 5 or 6 days of 
infection. 
When the fungus attacks a spikelet, the glumes, palezw and anthers are all 
infected. It forms asuperficial mycelium onthe surface of the glumes on which 
a good deal of spore formation takes place. 
CROSS-INOCULATION EXPERIMENTS. 
Maize Helminthosporium was cross-inoculated on Sorghum, rice, wheat, 
oats, barley, bajra and sugarcane. The inoculation was done on leaves, and 
plants were either covered with bell-jars or placed in big glass cages where 
there was sufficient moisture. After infection took place the bell-jars or glass 
cages were removed. In every case a control was kept. The following table 
shows the result of experiments :— 
pip Ad. 
Cross-inoculations on Sorghum. 
ie No. Control 
No. Date ee, ui footed Control Tre cpa REMARKS 
1 30-7-18 8 4 1 
2 5-8-18 8 4 1 
3 5-8-18 2 2 1 Bi The leaves were wounded 
4 11-8-18 8 3 1 
5) 18-8-18 10 6 1 
6 13-8-12 3 2 ] 
7 10-6-20 11 8 | Ae ais | 
8 7-8-20 11 6 
9 11-12-20 18 14 ewe 5 | The plants were kept in 
| awarm and moist room. 
Toran Ti |) toe oe | 62%, 
Out of 79 inoculations made, 49 were successful. Controls kept showed 
no sign of disease. The spots formed were like those ot jowar Helminthos- 
porium on jowar. There was always a good deal of spore formation on both 
sides of leaves. Maize Helminthosporium however spreads less rapidly on 
jowar than jowar Helminthosporium on jowar. 
