The purpose of this study was to assess the effects of increasing initial population density (Pi) of Meloidogyne incognita on nematode reproduction and growth of susceptible tomato (Lycopersicom esculentum cv. Round-41) at 25°C± 2 in growth chamber. 21-days-old tomato seedlings transplanted in13-cm dia. earthen pot was inoculated with Pi including 250, 500, 1000, 1500 eggs of M. incognita. Nema...

This study compares nematode prevalence in upland rice fields, which differed in cropping intensity, in Ùlree agroecological zones of Ivory Coast. Eighty nematode species from 35 genera were found associated with rice. Population densities of Helicorylenchus spp. were significantly lower in long fallows in the forest zone, but the mean population densities of ail other nematode genera and speci...

ABSTRACT The population density of the reniform nematode, Rotylenchulus reniformis, was monitored at depths of 0 to 30, 30 to 60, 60 to 90, and 90 to 120 cm in a tillage and crop sequence trial in south Texas in 2000 and 2001. Main plots were subjected to three different tillage systems: conventional tillage (moldboard plowing and disking), ridge tillage, and no-tillage. Subplots were planted w...

Soybean breeding lines and reported sources of nematode resistance were evaluated in repeated greenhouse tests for resistance to North Carolina populations of the soybean cyst nematode Heterodera glycines, reniform nematode Rotylenchulus reniformis, and the root-knot nematode species Meloidogyne incognita, M. arenaria, and M. arenaria. Lines from the soybean breeding program in Missouri that ha...

The relationships between densities of all members of a plant-parasitic nematode community and yield of 'Davis' soybean and between final and preplant population levels were examined in small plots on sandy soils in north-central Florida. Plant-parasitic nematodes present in the community included Belonolaimus longicaudatus, Criconemella sphaerocephala, Meloidogyne incognita, Paratrichodorus mi...

The behavior of a California isolate of the predaceous nematode, Odontopharynx longicaudata de Man, was studied in water agar culture. When feeding on an Acrobeloides sp. the predator completed its life cycle in 13 to 14 days at 25 C. Optimum temperature for reproduction of the predator was 25 C, few individuals survived at 10 C, and 30 C was lethal. Males were necessary for reproduction, and a...

A simulation model of a single sugarbeet, Beta vulgaris L., plant infected by the sugarbeet cyst nematode, Heterodera schachtii Schmidt, was developed using published information. The model is an interactive computer simulation programmed in FORTRAN. Given initial population densities of the nematode at planting, the model simulates nematode population dynamics and the growth of plant tap and f...

Correspondence analyses were used to explore the relationships between yield and populations of Pratylenchus zeae in an upland rice field and in a greenhouse experiment. Initial soil (Pi) and final root (Pf) population densities of P. zeae, and yield (Y) of rice cv. UPL Ri5 were determined at 490 spots in the field. Very low Y was linked to very high Pf. Low Y was linked to medium or high Pi an...

The effects of Pratylenchus penetrans upon yields of 'Veebrite' tomato were studied at initial soil population densities (P(i)) of 360, 2,010, 4,580, and 14,360 nematodes/kg of soil in 20-cm (i.d.) clay-tile microplots. The lowest P(i) appeared to stimulate fruit production. Higher P(i)'s suppressed fruit production (total weight of marketable tomatoes and numbers of intermediate- and large-siz...