Heteroderafengi n. sp. is described and illustrated from bamboo (Phyllostachys pubescens Mazel) based on morphology and molecular analyses of rRNA LSU D2D3 region and ITS. This new species belongs to the Cyperi group. Cysts are characterized by prominent vulval cone with ambifenestrate, bifurcate underbridge that is thicker in middle and a 47.0 (40.0-60.0) µm long vulval slit, but without bulla...

Sugarbeet yields were contpared with field populations of Heterodera schachtii Schmidt. The correlation between sugarbeet yields and viable larvae/g of soil was negative and high, but that between sugarbeet yields and viable cysts/g of soil was lower. Sugarbeet yields were also compared with H. schachtii populations by years of rotation with a nonhost crop. The coefficients of correlation (r) b...

During 1986 and 1988, selected farms in all of the major carrot-growing counties of Michigan were surveyed to determine the extent of infestation by Heterodera carotae and Meloidogyne hapla. Both species were found in all eight counties surveyed, but not on all farms. Heterodera carotae was recovered from 67.4% of the fields surveyed. Meloidogyne hapla was detected in 24.8% of the samples and f...

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...

Penetration of cabbage roots by Heterodera schachtii was suppressed 50-77% in loamy sand naturally infested with the nematophagous fungus Hirsutella rhossiliensis. When Heterodera schachtii was incubated in the suppressive soil without plants for 2 days, 40-63% of the juveniles had Hirsutella rhossiliensis spores adhering to their cuticles. Of those with spores, 82-92% were infected. Infected n...

1. The second-stage larva of the plant parasitic nematode Heterodera rostocfaensis shows very little movement while confined to the egg; on the other hand, the larva of the closely related Meloidogyne incognita is very active 2. Using interference microscopy, it is shown that the water content of the Heterodera larva increases immediately it is liberated from the egg while that of the Meloidogy...

Aldicarb, carbofuran, fensulfothion, and phenamiphos were tested in concentrations of 1-100 mug/ml for their effects on hatching of Heterodera schachtii. Exposure of cysts to 1 mug aldicarb or carbofuran/ml stimulated hatch whereas phenamiphos and, to a lesser degree, fensulfothion inhibited hatch. Addition of aldicarb to sugarbeet root diffusate or 4 mM zinc chloride suppressed activities of t...

The effects of Dactylella oviparasitica strain 50 applications on sugarbeet cyst nematode (Heterodera schachtii) population densities and plant weights were assessed in four agricultural soils. The fungus was added to methyl iodide-fumigated and nonfumigated portions of each soil. The soils were seeded with Swiss chard. Four weeks later, soils were infested with H. schachtii second-stage juveni...

Effects of constant and fluctuating temperature on development and reproduction of Heterodera cajani were studied on pigeonpea cv. ICPL 87 in growth chambers at 10, 15, 20, 25, and 30 C and in a greenhouse fluctuating between 22.2 and 37.8 C. Nematode penetration was greatest (P = 0.001) in roots at 25 C; there was no penetration at 10 C. The basal threshold temperature for development was calc...

Similar host ranges were found for Heterodera schachtii and a race of H. trifolii parasitic on sugarbeet in The Netherlands. Twenty-nine of 41 plant accessions evaluated were susceptible to H. trifolii. Five breeding lines of the interspecific hybrid Beta vulgaris-B. procumbens which are resistant to H. schachtii were highly susceptible to H. trifolii. An accession of B. maritima with partial r...