Water-displacement and WinRHIZO root-scanning methods were compared for efficacy of root damage assessment. Results from both methods were similar and a highly significant relationship was found between the two methods in trial one (r2 = 0.9968, P < 0.0001) and trial two (r2 = 0.9988, P < 0.0001). Both protocols provide consistent root volume measurements; however, water displacement is preferred as an economical method if a quick evaluation of a large amount of roots is essential. For a more detailed root morphological and architectural analysis, WinRHIZO root scanning provides additional information about several root parameters that cannot be measured by simple water displacement.

In turfgrass systems, nematicides are a valuable tool for managing plant-parasitic nematode populations, but few studies have examined nematicide effects on non-target nematodes. The study evaluated effects of turfgrass nematicide formulations of abamectin (Divanem SC), fluopyram (Indemnify), furfural (MultiGuard Protect EC), and fluensulfone (Nimitz Pro G) on non-target nematode populations in bermudagrass (Cynodon spp.). Nematicides were applied at labeled rates every four weeks as a summer treatment program from Samples were collected before the initial treatment and 2 d, 14 d, 56 d, and 238 d after the final treatment in both years for nematode community analysis. Data from each nematicide treatment were compared to the untreated at each sample date using analysis of covariance with initial population counts serving as the covariate. Abamectin had moderate impact and fluopyram had substantial impact on the nontarget nematodes. Furfural and fluensulfone had minimal impact on non-target nematodes. The results of this study suggest nematicides can impact non-target nematode densities in bermudagrass.

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Summary Populations reviously identified as Aphelenchoides besseyi were studied. Using an integrated approach, the A. besseyi species complex contains several cryptic species: A. besseyi sensu stricto, A. oryzae, A. pseudobesseyi sp. n. and other putative undescribed species. A population from Florida strawberry morphologically fits the A. besseyi of both Christie and Allen and is considered the only representative of this species. A Louisiana rice population fitted the descriptions of A. oryzae of both Yokoo and Fortuner; PUS length was consistently less than one-third of VA. Aphelenchoides oryzae, parasitising rice and other monocots, was re-established based on morphological and molecular datasets. Three populations from Florida ornamental plants (Dryopteris erythrosora, Echinacea sp. and Farfugium japonicum) differed from those of the two above-mentioned species and are described as A. pseudobesseyi sp. n. Populations previously identified as ‘A. besseyi’ from several countries were considered representatives of this new species, which usually had a large and conspicuous PUS, 8-14 μm wide and with a length greater than one-third of VA in 40-70% of studied specimens. Morphological variability made separation of A. pseudobesseyi sp. n. from A. oryzae and A. besseyi unreliable without the examination of numerous specimens and molecular analysis.

Root-knot nematodes are important pests of cut foliage crops in Florida. Currently, effective nematicides for control of these nematodes on cut foliage crops are lacking. Hence, research was conducted at the University of Florida to identify pesticides or biopesticides that could be used to manage these nematodes. The research comprised on-farm, field, and greenhouse trials. Nematicide treatments evaluated include commercial formulations of spirotetramat, furfural, and Purpureocillium lilacinum (=Paecilomyces lilacinus) strain 251. Treatment applications were made during the spring and fall seasons according to manufacturer's specifications. Efficacy was evaluated based on J2/100 cm 3 of soil, J2/g of root, and crop yield (kg/plot). Unlike spirotetramat, which did not demonstrate any measurable effects on Meloidogyne incognita J2 in the soil, furfural and P. lilacinum were marginally effective in reducing the population density of M. incognita on Pittosporum tobira. However, nematode reduction did not affect yield significantly. Although furfural and P. lilacinum have some potential for management of M. incognita on cut foliage crops, their use as a lone management option would likely not provide the needed level of control. Early treatment application following infestation provided greater J2 suppression compared to late application, suggesting the need for growers to avoid infested fields.

Caribbean fruit fly, also known as Caribfly or Anastrepha suspensa, is a major tephritid pest of guavas. A virulent entomopathogenic nematode (EPN) species was investigated to suppress the fruit-to-soil stages of Caribflies, which are also attacked by the koinobiont parasitoid Diachasmimorpha longicaudata in south Florida. The main objective was to develop a feasible and cost-effective EPN-application method for integrated pest management (IPM) of Caribfly to improve guava production. Naturally infested guavas were treated with increasing Heterorhabditis bacteriophora infective juvenile (IJ) concentration or rate (0, 25, 50, …, 1,600 IJs cm −2) in field trials to measure the optimum IJ rate and then examine sensitivity of producing guavas to inclusion of Heterorhabditis bacteriophora in Caribfly IPM plans. Relative survival of Caribfly in treatments significantly decreased with increasing IJ rate from 0 to 100 IJs cm −2. Similarly, probability of observing large numbers of parasitoid wasps (Diachasmimorpha longicaudata) in EPN treatments significantly declined with increasing IJ rate (0-100 IJs cm −2), even though the non-target effects of Heterorhabditis bacteriophora on relative survival of Diachasmimorpha longicaudata could not be determined because of few emerging parasitoid wasps. Optimum suppression (≥ 60%) of Caribfly was consistently achieved at 100 IJs cm −2 or 17,500 IJs fruit −1. Profitability analysis showed that Heterorhabditis bacteriophora can be included in Caribfly IPM tactics to produce guavas. Costs of EPNs in Caribfly IPM are minimized if Heterorhabditis bacteriophora is strategically applied by spot treatment of fruit. Repayment of costs of EPN-augmentation by spot treatments appears achievable by recovering 5.71% of the annual yield losses (≥1,963 kg ha −1 ≈ US$ 8,650 ha −1), which are largely due to Caribfly infestation. Hectare-wide EPN-augmentation (or broadcasting) method requires more fruit recovery than the total annual yield losses to repay its high costs. Profitability of guava production in south Florida will not be very sensitive to marginal costs of the spot treatment method, when compared to the field-wide broadcasting of Heterorhabditis bacteriophora.

Florida accounts for more than 75% of the national cut foliage production. Unfortunately, root-knot nematodes (RKN) (Meloidogyne spp.) are a serious problem on these crops, rendering many farms unproductive. Currently, information on the Meloidogyne spp. occurring on most commonly cultivated cut foliage crops in Florida, and tools for their rapid identification are lacking. The objectives of this study were to (i) identify specific RKN infecting common ornamental cut foliage crops in Florida and (ii) evaluate the feasibility of using the mtDNA haplotype as a molecular diagnostic tool for rapid identification of large samples of RKN. A total of 200 Meloidogyne females were collected from cut foliage plant roots. Meloidogyne spp. were identified by PCR and RFLP of mitochondrial DNA. PCR and RFLP of mitochondrial DNA were effective in discriminating the Meloidogyne spp. present. Meloidogyne incognita is the most dominant RKN on cut foliage crops in Florida and must be a high target for making management decisions. Other Meloidogyne spp. identified include M. javanica, M. hapla, Meloidogyne sp. 1, and Meloidogyne sp. 2. The results for this study demonstrate the usefulness of the mtDNA haplotype-based designation as a valuable molecular tool for identification of Meloidogyne spp.

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