Integrated pest management of plant-parasitic sting nematode (belonolaimus longicaudatus) on bermudagrass.

摘要

Use of bermudagrass (Cynodon dactylon) cultivars resistant or tolerant to sting nematode (Belonolaimus longicaudatus) is essential for sustainable turf management in sandy coastal soils of the Southeastern United States. Identification and development of tolerant bermudagrass cultivars and development of new integrated pest management (IPM) programs for plant-parasitic nematodes on golf courses in Florida are possible.;A multi-year field experiment evaluated five bermudagrass genotypes and four different nematicide regimes in a split-plot design with five replications in order to develop components for integrated pest management programs. Nematode samples were collected at three-month intervals to monitor the population density of B. longicaudatus and other plant-parasitic nematodes. Mixed models analysis and comparison of least squares means indicated no significant differences among the genotypes with regard to population density of B. longicaudatus, but there were differences among genotypes with regard to some of the other plant-parasitic nematodes, particularly spiral (Helicotylenchus paxilli) and ring (Mesocriconema ornatum) nematodes. There were significant nematicide regime responses on nematode population level after August, 2013 (P ≤ 0.05). A calendar-based IPM program rotating Bacillus firmus strain I-1582, furfural, Brassica juncea, and abamectin significantly reduced the nematode population density compared to a monitoring-based IPM program and the standard nematicide 1, 3-dichloropropene. In the untreated control, nematode population densities were significantly higher than the other treatments.;Another experiment compared rooting dynamics among turfgrass genotypes infected or non-infected by B. longicaudatus through in situ observation using minirhizotron method. 'Celebration', 'TifSport', and 'PI 291590' (bermudagrasses) and 'Floratam' St. Augustinegrass had significantly greater root parameters compared to the corresponding standard susceptible genotypes (P ≤ 0.05). Only TifSport had no significant root loss when infested with B. longicaudatus compared to the non-infested. Celebration and PI 291590 had significant root loss but retained significantly greater root densities than 'Tifway' in B. longicaudatus infested conditions (P ≤ 0.05). For all genotypes, root lengths were significantly greater at 0-5 cm, followed by 5-10 cm and 10-15 cm of vertical soil depth.;In a lysimeter study of nitrate (NO3- -N) leaching, mixed models analysis and comparison of LS means indicated significant increases in NO3- -N leaching from turf infested by B. longicaudatus than non-infested across genotypes of bermudagrass and St. Augustinegrass (P ≤ 0.05). Cumulative NO 3- -N leached from B. longicaudatus infested turf was less from bermudagrass genotypes PI 291590 and TifSport than from the standard cultivar Tifway (P ≤ 0.05). There was difference in cumulative NO3- -N leached between B. longicaudatus infested St. Augustinegrass genotypes.