European Journal of Plant Pathology (2014) 140, 481-490

María Dolores Vela, Ariadna Giné, Manuel López-Gómez, Francisco Javier Sorribas, Cesar Ornat, Soledad Verdejo-Lucas and Miguel Talavera (2014)
Thermal time requirements of root-knot nematodes on zucchini-squash and population dynamics with associated yield losses on spring and autumn cropping cycles
European Journal of Plant Pathology 140 (3), 481-490
Abstract: The present research was undertaken to evaluate the effects of soil temperature on the life cycle of root-knot nematodes (RKN) on zucchini-squash in growth chambers and to assess the relationship between Meloidogyne incognita soil population densities at planting (Pi), its multiplication rate, and crop losses of zucchini in field conditions. Thermal requirements for M. incognita and M. javanica were determined by cultivating zucchini plants in pots inoculated with 200 second stage juveniles (J2) of each Meloidogyne species at constant temperatures of 17, 21, 25, and 28 °C. Number of days from nematode inoculation until appearance of egg laying females and until egg hatching were separately recorded. For life cycle completion, base temperatures (Tb) of 12 ºC and 10.8 ºC and accumulated degree-days above Tb (S) of 456 and 526, were estimated for M. incognita and M. javanica, respectively. The relationship between fruit weight and M. incognita Pi fits the Seinhorst damage function, but differed accordingly to the cropping season, spring or autumn. Tolerance limits for M. incognita on zucchini were 8.1 J2 per 250 cm3 of soil in spring and 1.5 in autumn cropping cycles, and the minimum relative yields were 0.61 in spring and 0.69 in autumn. Zucchini-squash was a poorer host for M. incognita in spring than in autumn, since maximum multiplication rates (a) and equilibrium densities (E) were lower in spring (a = 16–96; E = 274–484) than in autumn (a = 270–2307; E = 787–1227).
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Link to article at publishers website
Database assignments for author(s): Miguel Talavera, Francisco Javier Sorribas, Soledad Verdejo-Lucas

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Meloidogyne javanica	Squash/pumpkin (Cucurbita)	Spain (continental)
	Meloidogyne incognita	Squash/pumpkin (Cucurbita)	Spain (continental)