Journal of Nematology (2005) 37, p. 386 (Noling et al.)

J.W. Noling, L.W. Duncan and J.P. Gilreath (2005)
Grower conducted root-gall surveys for field diagnosis and sampling for root-knot nematode
Journal of Nematology 37 (3), 386-386
44th Annual Meeting, Society of Nematologists, Fort Lauderdale, Florida, 9-13 July, 2005
Abstract: With methyl bromide soil fumigation, grower decisions regarding nematode monitoring or management were unnecessary because of the broad spectrum efficacy of the fumigant. With less effective pest management alternatives, new monitoring systems are needed , particularly in multiple cropping systems where crops are grown sequentially. Eight commercial vegetable fields were comprehensively surveyed using root gall assessments, rather than soil sampling, to characterize root-knot nematode (Meloidogyne spp.) spatial patterns and mean gall severity. Plants were systematically removed at increments of 15 m within rows sequentially across the field after final crop harvest. Basic sampling units consisted of six-row (198 m long) blocks. Mean galling was estimated for a range of sample sizes and targeted field locations for each of 96 blocks. An aggregated distribution was observed in most blocks. Random sampling from the data set revealed that sampling precision increased significantly when overall root gall severity was greater than 5 (scale 0 to 10) in a field block. At this level of root galling, a minimum of 4 to 6 plants/six-row block must be inspected to achieve acceptable precision. When the nematode problem is less severe and overall root gall severity less than 5, as many as 2 to 10 more plants must be inspected per block to assess nematode problems with the same sampling precision. These studies demonstrate that use of crop plants as bioindicators of nematode problems can be used to accurately characterize root-knot nematode infestation level and spatial pattern. The new sampling procedure is user friendly and will enhance nematode scouting and problem diagnosis capabilities of growers.
Database assignments for author(s): Larry W. Duncan

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Meloidogyne (genus)