Ecological Aspects of Four Turfgrass Nematode Genera on Putting Green Turf in Illinois

Studies were conducted to determine the following: (1) the effect of Tylenchorhynchus nudus on root growth of bentgrass and annual bluegrass; (2) the effect and interaction of T. nudus and Magnaporthe poae on bentgrass and annual bluegrass at 24C, 28C, and 30C; (3) the vertical distribution of T. nudus, Criconemella curvata, Helicotylenchus cornurus, and Hoplolaimus galeatus in the upper 5 cm of fenamiphos-treated and nontreated bentgrass putting green turf, and the effect of vertical distribution on the population dynamics of these genera; (4) the population dynamics of T. nudus, C. curvata, H. cornurus, and H. galeatus in the upper 5 cm of fenamiphos-treated and nontreated plots in mixed bentgrass and annual bluegrass putting greens. Root length and root weight of both bentgrass (Agrostis palustris) and annual bluegrass (Poa annua) were reduced significantly by T. nudus. Root length of bentgrass and annual bluegrass was reduced significantly by T. nudus at 24C, 28C, and 30C. A significant interaction between T. nudus and M. poae was indicated only on bentgrass at 28C and 30C: the effect of M. poae in the presence of T. nudus was not significant, but the effect of M. poae in the absence of T. nudus was significant. Dry root weight in putting greens was always greater from the 0-2.5 cm depth than from the 2.5-5 cm depth. The four species of nematodes were distributed nonuniformly in the soil profile on some sampling dates with nonuniform distribution most likely to occur from midsummer through the end of the growing season. When nonuniform vertical distribution was observed, T. nudus, C. curvata, and H. cornurus were more concentrated in the 0-2.5 cm depth, but H. galeatus was more concentrated in the 2.5-5 cm depth. Increasing depth in the soil and applying fenamiphos generally suppressed the population dynamics of T. nudus, C. curvata, and H. cornurus. The proportion of each species found 0-2.5 cm deep was stable during the growing season in both fenamiphos-treated and nontreated plots. Population dynamics in fenamiphos treated and nontreated plots appeared similar within a year but different between years. Damage threshold levels do not appear to have been reached during this study.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Plant Pathology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Davis, Richard Frederick

Contributors dc:contributor

• Wilkinson, Henry T.
• Noel, G.R.

• Agriculture, Plant Pathology

Identifier

(UMI)AAI9305503

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/72367