Pathogenicity of the root‐knot nematode Meloidogyne javanica on potato

Abstract

Host-parasite relationships and pathogenicity of Meloidogyne javanica on potatoes (newly recorded from Malta) were studied under glasshouse and natural conditions. Potato cvs Cara and Spunta showed a typical susceptible reaction to M. javanica under natural and artificial infections, respectively. In potato tubers, M. javanica induced feeding sites that consisted of three to four hypertrophied giant cells per adult female. Infection of feeder roots by the nematode resulted in mature large galls which usually contained at least one mature female and egg mass. In both tubers and roots, feeding sites were characterized by giant cells containing granular cytoplasm and many hypertrophied nuclei. Cytoplasm in giant cells was aggregated alongside the thickened cell walls. Stelar tissues within galls appeared disorganized. The relationship between initial nematode population density ( ] was fitted to fresh shoot weight and shoot height data of nematode-inoculated and control plants. Tolerance limits ( T ) for fresh shoot weight and shoot height of cv. Spunta plants infected with M. javanica were 0·50 and 0·64 eggs + J2s per cm 3 soil, respectively. The m parameter in that model (i.e. the minimum possible y -values) for fresh shoot weight and shoot height were 0·60 and 0·20, respectively, at P = 64 eggs + J2s per cm 3 soil. Root galling was proportional to the initial nematode population density. Maximum nematode reproduction rate was 51·2 at a moderate initial population density ( P = 4 eggs + J2s per cm 3 soil).

Effect of chemical treatment on physiological quality of seed and control of Meloidogyne javanica in watermelon plants

“…This can be attributed to both management of treatment techniques as well as an inherent low aggressiveness of M. javanica towards untreated watermelon plants. As per results published by Vovlas et al (2005), the RKN of specie M. javanica is less aggressive towards potato as compared to M. chitwoodi and M. hapla. Regardless, an infestation is still capable of severely impairing potato growth.…”

Development of a direct quantitative detection method for Meloidogyne incognita and M. hapla in andosol and analysis of relationship between the initial population of Meloidogyne spp. and yield of eggplant in an andosol

“…Also, the economic threshold level in burdock, cucumber and tomato was 1.6 J2/20 g soil (Plant protection station, 2011;Yamada, 1992). Vovlas et al (2005 and estimated the tolerance limits to M. javanica and M. incognita in potato and celery as 10 to 13 and 3 for eggs and J2s/20 ml soil, respectively. Collectively, the yield loss level of this study in eggplant was comparable to that in burdock, celery, cucumber and tomato, and markedly lower than that in carrot and spinach.…”

“…Economic threshold levels have been developed using the Baermann method for Meloidogyne spp. in carrot (Sano, 1988), burdock (Yamada, 1992), spinach (Di Vito et al, 2004), potato (Vovlas et al, 2005), carrot (Gugino et al, 2006), eggplant (Schomaker and Been, 2006), celery (Vovlas et al, 2008), and cucumber and tomato (Plant protection station, 2011). However, these economic threshold levels may be underestimated and variable.…”

Identificación morfológica, morfométrica y molecular de Meloidogyne incognita en higuera (Ficus carica L.) en Costa Rica.

“…De acuerdo con Vovlas et al (2005), la identificación correcta de este nematodo facilita la implementación de medidas de combate, como el uso de cultivares resistentes y de medidas cuarentenarias. Comúnmente, la identificación a nivel de especie se realiza mediante la observación de caracteres morfológicos y morfométricos (Taylor y netscher 1974, esser et al 1976, Taylor y sasser 1978; sin embargo, estos procedimientos requieren mucho tiempo y un amplio conocimiento sobre taxonomía de nematodos.…”