Soybean (Glycine max) producers in Ohio rarely use soybean cyst nematode (Heterodera glycines, SCN)-resistant cultivars because of concerns over limited yield potential and lack of resistance to Phytophthora sojae. A two-year study was initiated to determine grain yield and nematode population increase on soybean cyst nematode-resistant cultivars in maturity groups II and III in production fiel...

The reniform nematode, Rotylenchulus reniformis, has become a serious threat to cotton and soybean production in Arkansas and the mid-South. Yield losses caused by this nematode in the field range as high as 50%. In the absence of resistant cultivars, nematicides, and crop rotation are the available methods for controlling this nematode (Robbins et al., 1994). Limited information is available o...

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...

The application of geostatistics to plant nematology was made by evaluating soil and nematode data acquired from 200 soil samples collected from the A(p) horizon of a reed canary-grass field in northern Minnesota. Geostatistical concepts relevant to nematology include semi-variogram modelling, kriging, and change of support calculations. Soil and nematode data generally followed a spherical sem...

Parasitic nematodes infect thousands of plant species, but some plants harbor specific resistance genes that defend against these pests. Several nematode resistance genes have been cloned in plants, and most resemble other plant resistance genes. Nematode resistance is generally characterized by host plant cell death near or at the feeding site of the endoparasitic worm. The timing and localiza...

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...

Two hundred soil samples from the A(p) horizon of a reed canarygrass field overlaying several different but related soils in northern Minnesota were analyzed for plant-parasitic nematodes and 22 edaphic factors. Pratylenchus penetrans was the predominant nematode taxon. Others were Aglenchus agricola, Tylenchorhynchus spp., Heterodera trifolii, Paratylenchus spp., Tylenchus maius, and Criconeme...

Mature trees of eastern white, jack, Scotch, and shortleaf pines were inoculated with 25,000-34,000 pinewood nematodes, Bursaphelenchus xylophilus, isolated from infected Scotch pines in Missouri. Equal numbers of trees of each species inoculated with distilled water served as controls. Nine of fifteen Scotch pines died within 4 months of nematode infection or during the winter and early spring...

an ability of the fluorescent pseudomonad bacteria is to secrete such secondary metabolites as hydrogen cyanide, protease, salicylic acid as well as siderophore which prevent the growth of soil-habitant pathogens. tests were done for evaluating the materials produced by the said bacteria. in the tests' cultures, p. aeruginosa strains 7nsk2, utpf92, and utpf86 produced the most hydrogen cya...

Reproduction ofPratylenchus tho,'nei on carrot disk cultures at different time periods after inoculation, temperature, and initial inoculum density was studied. At 25 C and with an initial inoculum of 25 females per disk, the final nematode population increased with increasing time after inoculation, although the populations after 25 and 50 days were not different. Nematode numbers increased by...