Influence of Heterodera glycines on Interspecific and Intraspecific Competition Associated with Glycine max and Chenopodium album.
The influence of Heterodera glycines (soybean cyst nematode) on the interspecific and intraspecific competition associated with Glycine max (soybean) and Chenopodium album (common lambsquarters) was studied in 1988 and 1989 in three de Wit replacement series experiments in growth chambers and microplots. Glycine max was grown alone (1 plant/experimental unit), in intraspecific competition (2 plants/experimental unit), in interspecific competition with C. album, and in presence or absence of H. glycines. No significant effects of H. glycines and C. album on G. max growth were observed 14 days after planting. By 42 days after planting, both H. glycines and C. album had a negative (P = 0.05) influence on the growth of G. max. Relative crowding coefficients for G. max were lower and deviated (P = 0.05 and P = 0.001) from 1.0 in the presence of H. glycines, compared to that of C. album and early emerged C. album in the absence of the nematode, respectively. Glycine max, therefore, became less competitive than C. album. There was a trend that the presence of H. glycines decreased the competitiveness of G. max on measures of the aggressivity and relative mixture response. Heterodera glycines decreased the aggressivity of G. max (ca. 150-350%) and increased the relative effects of intraspecific interference on G. max (ca. 10-50%) and interspecific interference (ca. 60-350%) after 42 days of plant growth, compared with plants grown in the absence of H. glycines. No H. glycines x C. album interactions were detected. Observations showed that H. glycines and early emerged C. album inhibited the growth of G. max 5-13%, as measured by plant dry weight.
-T~~ intensity of intraspecific competition under different levels of light and nitrogen supply was assessed for the temperate zone herb, Chenopodium album. Plants were grown at two densities (one or six plants/pot) in a modified factorial design with three levels each of light and nitrogen availability. This yielded five light/nitrogen treatments which comprised two gradients, one extending fr...متن کامل
Multivariate Analysis of Selected Edaphic Factors and Their Relationship to Heterodera glycines Population Density.
The influence of selected soil physical and chemical factors on population density of Heterodera glycines was investigated in 1988 and 1989 in two different locations of a soybean (Glycine max) field. Soil variables of a Norfolk loamy sand were measured after planting soybeans susceptible to H. glycines. Cyst and egg populations were determined after harvest. Nematode population density was fou...متن کامل
A commercial seed treatment containing Pseudomonas cepacia was applied to Glycine max cv. Williams 82 (susceptible to Heterodera glycines) and was compared to Fayette soybean (resistant to H. glycines) for control of H. glycines at two locations in Illinois. The soil at the first location was sandy in texture and the field was irrigated, whereas the soil at the second location was a silty clay ...متن کامل
Soybean cyst nematode, Heterodera glycines, is found throughout soybean production areas of the United States, but the nematode's distribution is not uniform within states, counties, and individual fields. The goal of this research was to determine the spatial pattern of H. glycines population density in a field in southeastern Missouri and whether it changed over time in the absence of managem...متن کامل
Stability of Heterodera glycines (Tylenchida: Heteroderidae) juvenile hatching from eggs obtained from different sources of soybean, Glycine max
Stability of Heterodera glycines (Tylenchida: Heteroderidae) juvenile hatching from eggs obtained from different sources of soybean, Glycine max Edward P. MASLER 1,∗, Patricia A. DONALD 2 and Sandra SARDANELLI 3 1 Nematology Laboratory, Agricultural Research Service, Beltsville, MD 20705, USA 2 Crop Genetics and Production Research Unit, Agricultural Research Service, Jackson, TN 38301, USA 3 P...متن کامل