Plant Disease (2016) 100, 592-600

Frank S. Hay, Kathy Ophel-Keller, Diana M. Hartley and Sarah J. Pethybridge (2016)
Prediction of potato tuber damage by root-knot nematodes using quantitative DNA assay of soil
Plant Disease 100 (3), 592-600
Abstract: Root-knot nematodes (Meloidogyne fallax and M. hapla) cause significant reductions in potato yield by reducing tuber quality. Concentrations of M. fallax and M. hapla DNA in soil were determined by quantitative polymerase chain reaction following sampling at planting and harvest within 78 fields across 3 years in Australia. Meloidogyne spp. were also detected using a tomato bioassay. M. fallax was more prevalent than M. hapla and DNA concentrations of M. fallax in soil were significantly higher in samples collected at harvest compared with those at planting. In contrast, M. hapla DNA in soil did not significantly change from planting to harvest. Using receiver operating characteristic curve analysis, M. fallax DNA in soil at planting and harvest was a highly accurate predictor of tuber damage at harvest and galling on tomato. Prediction accuracy for tuber damage was highest for M. fallax DNA compared with M. hapla or M. fallax + M. hapla. Both Meloidogyne spp. were detected in the peel of asymptomatic certified seed. For M. fallax, the addition of seedborne inoculum did not improve tuber damage predictions. This suggested that soilborne M. fallax populations contributed most substantially to tuber damage. These findings highlight the utility of this approach for predicting risk of crop damage from nematodes. The use of this technique as a practical management tool is discussed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Sarah J. Pethybridge

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
thresholds/decision-support systems

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Meloidogyne fallax	Potato (Solanum tuberosum)	Australia (South+SE)
	Meloidogyne hapla	Potato (Solanum tuberosum)	Australia (South+SE)