Root-knot nematodes (Meloidogynespp.) are the most important pests of vegetables, field crops, and ornamental plants. During our previous study, twenty eight okra cultivars were examined against resistance and Pusa Swami was ranked the most susceptible. The purpose of this study was to investigate the effects of increasing initial population density (Pi) of M. incognita on nematode reproduction...

The bacterium Xenorhabdus nematophila is a mutualist of the entomopathogenic nematode Steinernema carpocapsae. During its life cycle, the bacterium exists both separately from the nematode and as an intestinal resident of a nonfeeding nematode form, the infective juvenile (IJ). The progression of X. nematophila from an ex vivo existence to a specific and persistent colonization of IJs is a mode...

Harmony grape rootstock displays resistance to several Meloidogyne spp. but that resistance is not durable in commercial vineyard settings. A 2-year experiment in a microplot setting revealed host specificities of two virulent populations of Meloidogyne arenaria and an avirulent population of Meloidogyne incognita. In a subsequent split-root experiment, the avirulent nematode population was dem...

TWO POT EXPERIMENTS, IN CONSECUTIVE YEARS, WERE CONDUCTED UNDER OUTDOOR CONDITIONS DURING THE WHEAT GROWING SEASON TO EXAMINE THE RELATIONSHIP BETWEEN INCREASING INITIAL POPULATION DENSITIES (PI: 0-3,000 cysts/pot) of Heterodera avenae and corresponding responses of wheat cv. Yecora Rojo. Results of both experiments were very similar. The nematode suppressed plant height, root and biomass dry w...

Soil moisture and the nematode population density in aldicarb-treated soil influenced control of the sugarbeet nematode, Heterodera schachtii. Greater numbers of nematode larvae infected 14-day-old sugarbeet seedlings growing in aldicarb-treated soil at 20-30% than at 80-100% field capacity (F. C.), and plant growth was inversely related to nematode infection and the nematode population density...

the present study is based on the investigation of a soil hyphomyces, paecilomyces lilacinus, an opportunistic bio-control agent, in controlling root-knot nematode meloidogyne javanica on tomato in greenhouse conditions. p. lilacinus, effectively promoted the growth of plants inoculated with m. javanica by suppressing its pathogenesis as root galling by the nematode and egg mass production was ...

A degree-day model was derived to predict egg hatch for Criconemella xenoplax. Eggs collected from gravid females were incubated in distilled water at constant temperatures of 10-35 C. Sixty-six percent of all eggs hatched between 13 and 32 C, and 42% hatched at 10 C. All eggs aborted above 32.5 C. Between 25 and 32 C, 8.5 +/- 0.5 days were required for egg hatch. Degree-day requirement for egg...

American boxwood, Buxus sempervirens var. globosum, was tolerant of Helicotylenchus dihystera [in field microplots] as measures of plant growth were similar to the control and nematode densities were maintained at high levels (1,705-1,810/500 cm(3) soil after 29 months). Boxwood was intolerant of Pratylenchus vulnus at initial densities of 163, 281, or 475 nematodes per 500 cm(3) soil. In compa...

Combinations of winter and fall cover crops were evalu­ ated for the management of plant-parasitic nematodes. The winter cover crops examined were rye (Secale cereale) and narrow-leafed lupin (Lupinus angustifolius) and the fall cover crops were soybean (Glycine max), cowpea (Vigna unguiculata), sorghum-sudangrass (Sor­ ghum bicolor x S. sudanense), sun hemp (Crotalaria juncea), and corn (Zea m...