ABSTRACT
The cultivated sunflower belongs to the Compositae family. The flowering behavior facilitates cross-pollination, and insects, particularly the bees, represent the essential vector of sunflower pollen. The degree of cross-pollination may be to the extent of 100%. The center of origin of the sunflower is believed to be North America from where it has spread to Europe and Asia. Sunflower cultivation in Asian countries is comparatively recent. Asia accounts for nearly 20%–22% of the global sunflower and contributes to about 18% of the production. The productivity of sunflower in Asia is about 1.0 ton/ha, which is lower than the world average. The emergence of new diseases and large climatic variations, particularly recurrence of drought stress during critical growth stages, has affected stability and yield on a regular basis. With continuous cropping in the same field area, the crops suffer from diseases resulting in large losses in yield.
