The document discusses the spread of the wheat rust fungus Puccinia graminis in South Asia. Uredospores from infected wheat crops in central Nepal in October act as the inoculum for infections in the northern plains in February. The uredospores then travel south through the Terai region, infecting summer wheat crops in the Nilgiri and Puleny hills and early sown crops in Mysore and neighboring areas. The fungus multiplies on these southern crops and spreads northward, severely affecting the Gangetic plains from October to November as it completes its annual cycle.

1. PUCCINIA PATHWAY

2. QUEST FOR SURVIVAL OF
UREDOSPORES
• Dr.K.C.Mehta & his associates through
aeroscopic studies brought into light the
mystery behind the spread of uredospores in
the subcontinent.

3. EVENTS IN
NEPAL
In central Nepal wheat is
sown during August &
harvested in January
It gets infected by
P.graminis during
October

4. • The uredospores from central Nepal acts as
the INOCULUM for the infection of main crop
in the Northern plains.

5. Uredospores
travel to south
via TERAI
REGION

6. The wheat crops in northern plains
are infected during February each
year.

7. The uredospores travel to summer wheat crops
of Nilgri & Puleny hills & also spreads to early
sown crops of Mysore & other neiboughring
places.

8. • Fungi multiplies on summer hill crops &
spreads to early sown crops in southern
plains.
• The fungi multiplies & spreads Northward
during October- November. The Gangetic
plains are severely affected during
February – March.

9. NEPAL
October
NORTHERN
PLAINS
FEB
NILGRI HILLS
DURING
SUMMER
SOUTHERN
PLAINS
EARLY SOWN