NOTES ON THE SEASONAL FLUCTUATION OF THE NEMATODE- TRAPPING FUNGI POPULATION IN ORCHARDS AT THE VICINITY OF BEIJING
捕食线虫真菌在北京地区果园中的季节性分布

Seasonal distribution of nematode-trapping fungi in 2 apple and 2 grape orchards in the vicinity of Beijing was investigated from April 1990 to April 1992. 199 fungal strain, belonging to 3 genera and 16 species, were isolated. Arthrobotrys dactyloides was the predominant species in all four orchards, and A. oligospora, A. conoides and Stylopage sp. were frequently encountered. The fungi were abundant in late spring and early summer and slightly so in the autumn. A SAS stepwise regression between the seasonal fluctuation of nematode-trapping fungi and soil moisture, soil temperature and the density of total nematodes as well as styled nematodes indicated that soil temperature was positively correlated with the number of nematode-trapping fungi in a linear tendency while the density of total nematodes was correlated with nematode-trapping fungi in a sigmoid state