TIMING OF NEMATICIDE APPLICATIONS FOR CONTROL OF Belenolaimus longicaudatus ON GOLF COURSE FAIRWAYS By PAURIC C. MC GROARY A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2007 1 © 2007 Pauric C. Mc Groary 2 ACKNOWLEDGMENTS I would like to thank Dr. William Crow for his scientific expertise, persistence, and support. I am also indebted to my other committee supervisors members, Dr. Robert McSorley and Dr. Robin Giblin-Davis, who were always available to answer questions and to provide guidance throughout. 3 TABLE OF CONTENTS page ACKNOWLEDGMENTS ...............................................................................................................3 LIST OF TABLES...........................................................................................................................6 LIST OF FIGURES .........................................................................................................................7 ABSTRACT.....................................................................................................................................8 CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW ..............................................................10 Introduction.............................................................................................................................10 Belonolaimus longicaudatus...................................................................................................11 Taxonomy........................................................................................................................11 Biology ............................................................................................................................11 Geographic Distribution ..................................................................................................14 Disease Symptoms and Pathogenicity on Warm-Season Turfgrasses ............................14 Bermudagrass ..................................................................................................................15 Cultural Practices.............................................................................................................16 Objectives ...............................................................................................................................17 2 SEASONAL FLUCTUATIONS OF Belonolaimus longicadatus IN BERMUDAGRASS ...............................................................................................................18 Introduction.............................................................................................................................18 Materials and Methods ...........................................................................................................19 Experimental Sites...........................................................................................................19 Experimental Design .......................................................................................................20 Sampling and Evaluation.................................................................................................21 Data Analysis...................................................................................................................21 Results.....................................................................................................................................22 Discussion...............................................................................................................................24 3 TIMING OF NEMATICIDE APPLICATIONS ON TURF TO REDUCE DAMAGE CAUSED BY Belonolaimus longicaudatus ...........................................................................32 Introduction.............................................................................................................................32 Materials and Methods ...........................................................................................................33 Sampling and Evaluation........................................................................................................34 Nematodes .......................................................................................................................34 Roots................................................................................................................................35 Data Analysis...................................................................................................................35 Results.....................................................................................................................................35 4 Discussion...............................................................................................................................36 4 SUMMARY............................................................................................................................42 LIST OF REFERENCES...............................................................................................................45 BIOGRAPHICAL SKETCH .........................................................................................................50 5 LIST OF TABLES Table page 2-1. Linear regression number of Belonolaimus longicaudatus/300 cm3 of soil (Y) on root length 300 cm3 of soil (x) from four golf course fairways in Florida sampled monthly. .............................................................................................................................31 6 LIST OF FIGURES Figure page 2-1 Population densities of Belonolaimus longicaudatus and root lengths from 300 cm3 of soil from bermudagrass and soil temperatures at the Ft. Lauderdale Research and Education Center, Ft. Lauderdale, FL (January 2005 – December 2005). Data are means ± standard error.......................................................................................................27 2-2 Population densities of Belonolaimus longicaudatus and root lengths from 300 cm3 of soil from bermudagrass and soil temperatures at Ironwood Golf Course, Gainesville, FL (February 2005 - January 2005). Data are means ± standard error.........28 2-3 Population densities of Belonolaimus longicaudatus and root lengths from 300 cm3 of soil from bermudagrass and soil temperatures at Sandpiper Golf Course, Sun City, FL (March 2006 - November 2006). Data are means ± standard errors...........................29 2-4 Population densities of Belonolaimus longicaudatus and root lengths from 300 cm3 of soil from bermudagrass and soil temperatures at Club Renaissance Golf Course, Sun City, FL (March 2006 - November 2006). Data are means ± standard errors...........30 3-1 Effects of application time of 1,3-dichloropropene on Belonolaimus longicaudatus population densities at Sandpiper Golf Course, Sun City, FL (March 2006 - November 2006). ...............................................................................................................38 3-2 Effects of application time of 1,3-dichloropropene on root length at Sandpiper Golf Course, Sun City, FL (March 2006 - November 2006). Asterisk indicates treatment is different from untreated (P < 0.1). .................................................................................39 3-3 Effects of application time of 1,3-dichloropropene on Belonolaimus longicaudatus population densities at Club Renaissance Golf Course, Sun City, FL (March 2006 - November 2006). ...............................................................................................................40 3-4 Effects of application time of 1,3-dichloropropene on root length at Club Renaissance Golf Course, Sun City, FL (March 2006 - November 2006)........................41 7 Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science TIMING OF NEMATICIDE APPLICATION FOR CONTROL OF Belonolaimus longicaudatus ON GOLF COURSE FAIRWAYS By Pauric C. Mc Groary May 2007 Chair: William T. Crow Major: Entomology and Nematology Sting nematode (Belonolaimus longicaudatus) is an important pest of bermudagrass (Cynodon dactylon), and other turfgrasses grown in the southeastern United States. On bermudagrass, B. longicaudatus causes severe damage to lateral roots, decreased water and nutrient uptake, and decreased rates of evapotranspiration leading to reduced turf quality, color, and density. Field experiments from January 2005 to March 2007 were conducted to monitor the seasonal dynamics of B. longicaudatus populations, bermudagrass root growth, and soil temperatures on four bermudagrass fairways in Florida in order to develop an empirical optimum time for nematicide application. Seasonal fluctuations in B. longicaudatus and root growth varied among locations and years, but similar trends were observed in all four trials for nematodes and root growth. Linear regression models relating root length to nematode population densities (0 - 15 cm depth) were significant (P ≤ 0.10) at three of four sites. At the FLREC site, root length and nematode population were correlated (P ≤ 0.10) in April and May. At the IW site root length was related to nematode population (P ≤ 0.10) in June, September, and October. At the SP site, root length and B. longicaudatus population densities were significantly related (P ≥ 0.10) only in July. However, regression