POPULATION FLUCTUATIONS OF 3 NEMATODE GENERA IN PUTTING GREENS IN NORTHERN ILLINOIS

Field experiments were conducted in 1989 and 1990 to examine the popul ation fluctuation patterns of Tylenchorhynchus nudus, Criconemella cur vata, and Helicotylenchus cornurus in mixed bentgrass and annual blueg rass putting greens on two golf courses near Chicago, Illinois, to det ermine if fluctuation patterns could be extrapolated to unsampled gree ns. Fenamiphos-treated and untreated plots were established on seven p utting greens on two golf courses. Greens were sampled intensively fiv e times during the growing season, and statistical comparisons of popu lation levels per gram of root were made among dates for each green. P opulation levels per gram of root changed significantly on all greens in both years for each of the three nematode populations. Within a put ting green in either year, population fluctuation patterns in fenamiph os-treated and untreated plots were similar. Population fluctuation pa tterns were different between years, however. Within a year, populatio n fluctuation patterns among greens showed similarities indicating tha t carefully monitoring a few locations may allow extrapolation of popu lation fluctuation data to other locations within that year.