2?0 DOWNY MfLDEW OF BAJRI AND JoWAft. 



remains. The oospores are found even on the sheath of the leaf 

 encircling the stem. The plant never attains the usual height and 

 no head is produced. The disease is confined to the individual 

 plants which are affected from the beginning. 



2nd form : — The disease appears after the plant is about two 

 months old. The top leaves of the affected plants become white, 

 the whiteness extending to the base of the side leaves also. Irregular 

 streaks appear on these white leaves, oospores are formed and soon 

 shredding begins. On the lower leaves pale yellow patches appear 

 at the base, on which the conidial stage is found. In this form the 

 conidial stage follows the oogonial or, in some cases, they appear 

 simultaneously. The affected plants rarely produce heads, and 

 the heads, if formed, are much reduced in size and have a few small 

 grains but are not malformed. It is the most common and prom- 

 inent form in the fields and presumably causes considerable damage. 

 Here also the disease is confined to the attacked plants and does 

 not seem to spread from plant to plant. 



3rd form : — The affected plants have on their leaves long, 

 narrow streaks and patches. The streaks are first pale yellow in 

 colour, become orange and finally turn dark brown after the cells of 

 the attacked parts are dead. The conidial stage is found on both 

 the surfaces of the patches, but more on the lower side. The patches 

 appear to spread from the lower leaves to the upper leaves and from 

 the apex of the leaf towards the base. The upper leaves have the 

 patches only towards the tip, the middle ones have more than half 

 of their surface covered with them, while the lower ones have 

 their surface completely covered. The patches are bounded by 

 prominent veins and increase mostly longitudinally. When the 

 attack is severe and complete the whole leaf dries up after turning 

 dark brown. No oospores are formed and no shredding of the leaf 

 is observed. The plants produce normal heads. The disease seems 

 to spread from plant to plant and in the field big patches of affected 

 plants are visible. 



From these three different modes of attack it seems that, in 

 bajri and jowar, where the plants show disease from the beginning, 



