In north India and central India, the black rust inoculum cause from

Answer: Option A

In north India and central India, the black rust inoculum is caused from the South.
Stem rust, also known as cereal rust, black rust, red rust, or red dust, is caused by the fungus Puccinia graminis, which causes significant disease in cereal crops. Crop species that are affected by the disease include bread wheat, durum wheat, barley and triticale.
The annual recurrence of stem rust of wheat in North Indian plains was discovered by Prof. K. C. Mehta. The long-distance dissemination of stem rust from the southern foci to central India is reported to be associated with cyclonic rains.