S D Van Gundy

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Nematodes of three genera (Acrobeloides sp., Aphelenchus avenae, and Scutellonema brachyurum) were induced to coil and enter anhydrobiosis in drying soil of two types: sandy loam and loamy sand. Coiling was studied in relationship to soil moisture characteristics. Coiling and the physiological state of anhydrobiosis occurred before the water in sandy soils(More)
The effect of methyl bromide (MB) was tested on active and anhydrobiotic Aphelenchus avenae. A. avenae was induced into anhydrobiosis by three different techniques. Both active and anhydrobiotic nematodes were subjected to 3,000 mu1 MB/liter air for 14 periods from 0 to 82 h. Anhydrobiotic nematodes were more resistant to fumigation than active nematodes,(More)
The vertical migration of M. incognita juveniles introduced at 20 cm from the roots was studied in five natural soils, 100% silica sand, 95% silica sand with 5% clay, 90% silica sand with 10% clay, and 95% silica sand with 5% clay as a concentrated layer. In natural soils the percentage of juveniles capable of migrating 20 cm and penetrating the roots(More)
Wheat cultivars Anza and Produra grown in winter in California were planted in Meloidogyne incognita infested and noninfested sandy loam plots in October (soil temperature 21 C) and November (soil temperature 16 C) of 1979. Meloidogyne incognita penetrated roots of mid-October planted Ataza (427 juveniles/g root), developed into adult females by January,(More)
Starving Aphelenchus avenae survived 3-4 weeks in microaerobic and anaerobic environments, but Caenorhabditis sp. survived less than 80 hr. Aerobically, both nematodes metabolize neutral lipid reserves: there was no microaerobic ( <5% O) or anaerobic neutral lipid catabolism. Early in anaerobiosis both nematodes utilized endogenous glycogen. Caenorhabditis(More)
In microaerobic and anaerobic environments the principal glycolytic end-product of A. avenae and Caenorhabditis sp. was lactic acid during the first 12-16 hr, after which it was ethanol. Upon return to aerobiosis, (1)C-labeled ethanol in the medium was utilized by the nematodes; (1)CO and some (1)C-labeled glycogen was detected. Total dry weight loss of(More)
The efficacy of avermectins B and B for control of Meloidogyne incognita on tomato was studied in pots and field plots for two seasons. Avermectins were applied as granules and liquid in furrows or by low pressure drip irrigation systems, at rates ranging from 0.093 to 0.34 kg a.i./ha, as single or multiple applications. Levels of control comparable to(More)
Variability in the reproduction of the four races ofMeloidogyne incognita on the soybean cuhivars Pickett 71 and Centennial was studied in growth chamber experiments. Analysis of variance in the number of eggs produced by the races 6 weeks after the plants had been inoculated with 5,000 eggs of each race revealed that the nematode race by soybean cultivar(More)
In laboratory testing, egg hatch of Tylenchulus semipenetrans was stimulated at concentrations of 1 and 10 microg/ml aldicarb solution and inhibited at 50 and 100 microg/ml. Aldicarb was more inhibitory to egg hatch than the aldicarb sulfoxide and the aldicarb sulfone. Inhibition of hatch at the high concentration was associated with delays in the molting(More)