A replicated field study was conducted from 1972 to 1980 involving soybeans grown in 2-, 3-, and 4-year rotations with maize in soil infested with Meloidogyne incognita. Monocultured soybeans were maintained as controls. Cropping regimes involved root-knot nematode susceptible and resistant soybean cultivars and soybeans treated and not treated with nematicides. Yields of susceptible cultivars ...

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...

Several abiotic and biotic stresses can affect soybean in a growing season. Heterodera glycines, soybean cyst nematode, reduces yield of soybean more than any other pathogen in the United States. Field and greenhouse studies were conducted to determine whether preemergence and postemergence herbicides modified the reproduction of H. glycines, and to determine the effects of possible interactive...

The following stress factors were tested for their effect on the susceptibility of Plutella xylostella (L.) to Bacillus thuringiensis Berliner: (a) exposure to low doses of the synthetic pyrethroid cypermethrin, (b) treatment with low doses of the secondary plant compound, azadirachtin and (c) development on partially resistant cabbage cultivars. B. thuringiensis-related mortality of cypermethr...

Root-infecting nematodes are a major cause of white clover, Trifolium repens, not reaching its potential in New Zealand pastures. Resistance and/or tolerance are the preferred control options. Greenhouse-based, recurrent selection programs have developed resistance to Meloidogyne trifoliophila and Heterodera trifolii, and a field-based program has developed tolerance. Lines from these programs ...

Selected cotton cultivars were evaluated for resistance to the southern root-knot nematode, Meloidogyne incognita, in greenhouse and field experiments. Cotton cultivars LA 887, Auburn 634, and NemX cotton were highly resistant to three North Carolina populations of root-knot nematode in greenhouse experiments compared to susceptible cultivars. The relative susceptibility of cultivars tested in ...

Nematode management decisions should be based, in part, on knowledge of the damage threshold population density, and this value is likely to vary based on the level of resistance of the cotton cultivar. The damage functions of two cotton cultivars resistant to the root-knot nematode (Meloidogyne incognita) were compared with that of a susceptible cultivar in field microplots using a 3 x 7 facto...

Feeding activities of the tea green leafhopper, Empoasca vitis (Gothe) (Homoptera: Cicadellidae), on resistant and susceptible cultivars of tea plants (Camellia sinensis L.) were recorded and analyzed using the direct current electrical penetration graph (EPG) system. Six distinct EPG waveforms characterizing the feeding behavior of the tea green leafhopper, categorized as waveforms A, C, E, S,...

Soybean cultivars from maturity groups III-V were grown in Heterodera glycines-infested locations in northeastern and southeastern Kansas from 1991 through 1994. Yield performance and nematode reproduction were significantly (P <0.01) affected by host response to H. glycines and year, whereas effects of cultivars within host response categories and cultivar x year interactions were generally ne...