ABSTRACT
The host response of fifteen winter squash (Cucurbita maxima) and five pumpkin (Cucurbita moschata) dihaploid genotypes to Meloidogyne arenaria, M. incognita, M. javanica, and M. luci was screened in pot experiments. Root galling and nematode reproduction were detected in all combinations of plant genotype and nematode species. Ten genotypes of C. maxima and three genotypes of C. moschata were considered highly resistant (<10% of the susceptible genotype) or moderately resistant (<50% of the susceptible genotype) to one or more Meloidogyne species based on nematode reproduction as a percentage of the most susceptible genotype. Genotypes 55CA15-A3 and G14-IP1 of C. maxima were highly resistant to M. luci and M. arenaria, respectively. Both 14BO01-O2 and G9-A4 genotypes of C. moschata were considered highly resistant to M. arenaria. However, these genotypes still allowed significant nematode reproduction because egg number per plant was higher than initial number of eggs used as inoculum, indicating that all genotypes were hosts.
ABSTRACT
ABSTRACT An experiment was conducted to search the efficacy of radish (Raphanus sativus) and arugula (Eruca sativa) for the control of Meloidogyne arenaria in the commercial tomato growing greenhouse. R. sativus and E. sativa were used as winter cycle crops and lettuce as a susceptible crop and 4 months after sowing, host level of the treatment plants was evaluated. All parts of R. sativus and E. sativa were incorporated except lettuce was covered with transparent polyethylene film for 4 weeks. R. sativus and E. sativa had not any root galls, and these plants caused reducing number of juveniles in the soil, in contrast to control and lettuce plots before growing tomato. Gall index and egg masses were significantly decreased on tomatoes in plots of applied biofumigation with E. sativa and R. sativus. It was concluded that growing R. sativus and E. sativa as a winter cycle plants before susceptible plants would be helpful to reduce the damage of root-knot nematode M. arenaria and increased crop yields.
Subject(s)
Tylenchoidea , Brassicaceae , Raphanus , Fumigation , NematodaABSTRACT
Temperate vegetable and nursery industries face significant challenges in managing Meloidogyne hapla, a plant-parasite for which few resistant cultivars and/or viable alternatives to methyl bromide exist. N-Viro Soil(R) (NVS), an alkaline-stabilized biosolid product, has soil nutrition enrichment capacity and potential for plant-parasitic nematode suppression. In three sets of experiments, we investigated the effects of NVS on M. hapla populations from Rhode Island (RI), Connecticut (CT), New York, Geneva (NYG) and Lyndonville (NYL), and Michigan (MI), and growth of tomato cv 'Rutgers' in five soils commonly used for vegetable and nursery crop production in the Great Lakes Region of the USA. Either 0 (control) or 600 eggs/100 cm(3) of soil per M. hapla population were added in all experiments. In the first set, NVS was applied at rates of 0, 1, 2 and 4 g/100 cm(3) of sandy loam soil (pH 7) and resulted in variable responses on the numbers of nematodes recovered and plant growth at 30 and 90 days (25+/-2 degrees C); however, the 2g NVS treatment consistently increased plant growth. Either 0 or 2 NVS/100 cm(3) were applied to a coarse loamy (pH 4.5) and sandy loam (pH 8, second set of experiments), and muck (pH 5.5), loamy sand (pH 7.1) and sandy loam (pH 7.5, third set of experiments) soils and experiments terminated four weeks after nematode inoculation. Across experiments, the effect of NVS on the M. hapla populations varied. Generally nematode infection decreased plant growth. NVS increased soil pH the most in muck and the least in sandy loam soil. The most consistent interaction effects of NVS*soil, NVS*M. hapla, soil*M. hapla and/or NVS*soil*M. hapla across the experiments indicate that NVS affects M. hapla populations in different ways in different soil types, suggesting that NVS application is likely to be site-specific. These findings further provide basis that may potentially explain reports of variable effects of NVS on nematodes and how future studies may account in furthering our understanding of NVS activities for M. hapla management.
