PATHOGENICITY AND REPRODUCTIVE POTENTIAL OF <I>MELOIDOGYNE MAYAGUENSIS</I> AND <I>M. FLORIDENSIS</I> COMPARED WITH THREE COMMON <I>MELOIDOGYNE</I> SPP.

Abstract

Cetintas, R., R. Kaur, J. A. Brito, M. L. Mendes, A. P. Nyczepir, and D. W. Dickson. 2007. Pathogenicity and reproductive potential of Meloidogyne mayaguensis and M. floridensis compared with three common Meloidogyne spp. Nematropica 37:21-31. The pathogenicity and reproductive potential of Meloidogyne mayaguensis and M. floridensis, two new species recently reported in Florida agriculture, were compared to those of M. arenaria race 1, M. incognita race 4, and M. javanica race 1 on tomato (Lycopersicon esculentum) in field microplots. Three trials were conducted, one in fall and two in spring using tomato cvs. Solar Set and Florida 47, respectively. Two levels of each nematode (low = one egg or second-stage juvenile (J2)/100 cm3 of soil; high = three eggs or J2/100 cm3 of soil) were used with nine replicates each. Common vetch (Vicia sativa) was used in trial one as a winter cover crop. Nematode densities in the soil, root-galling, eggs per gram fresh root, shoot fresh weight and plant height were recorded. No significant interaction was observed between root-knot nematode species and inoculum levels in trials one or two except for eggs/g of fresh root and J2/100 cm3 of soil at harvest of cv. Solar Set in trial one, fall 2004. All five species of root-knot nematodes induced root-galling and reproduced well on both tomato cultivars, except M.floridensis, which produced less galling in all trials. Meloidogyne mayaguensis produced the highest percentage of root-galling on cv. Solar Set in the fall trial but not on cv. Florida 47 in spring trials. However, M. arenaria showed a higher reproductive potential on cv. Solar Set in the fall trial. Galling on vetch was similar among M. arenaria, M. incognita, M. javanica, and M. mayaguensis, but numbers of J2 in soil were lower for M. floridensis and M. javanica than for M. arenaria, M. incognita, and M. mayaguensis. Although M. mayaguensis was observed to induce large galls on tomato, yield reduction occurred in only one of two trials in spring of 2005.