Based on the results of field survey, pathogenesity tests and electron microscope observations, the primary infection of wheat mycoplasma-like organism blue dwarf disease (WMBD) transmitted by vector leaf hopper Psammotettix striiatus occured mainly in autumn wheat seedling period and the diseased volunteer wheat seedlings were the main infection sources.

A new leaf disease of maize ,mainly caused by Curvularia lunata (Wakker) Boed is becoming prevalent in recent years in north China and the disease was found in Sichuan in 1999 firstly.

Studies on over-summering and primary infectious pathogen of strawberry powdery mildew in greenhouses in East Zhejiang;

The primary sources of infection of Curvlaria lunata were studied in several methods.