Effect of Rotylenchulus reniformis on Yield and Nitrogen, Potassium, Phosphorus and Amino Acid Content of Seed of Glycine max

R. V. Rebois, W. C. Johnson


Soybean cultivars varied in their response and tolerance to low initial Rotylenchulus reniforrnis populations of 10,000 nematodes/3.8 liters of soil, but a high initial population of 25,000 consistently reduced yields on resistant and susceptible cultivars by an average of 33.1%. At the 10,000 nematode inoculum level, dry seed yields of Hood decreased while those of Pickett increased significantly. Generally, total phosphorus decreased 11.1 and 11.5% and potassium increased 5.9 and 4.5% in seeds harvested from plants receiving initial inoculum levels of 5000 and 10,000 nematodes/pot, respectively. Little change in the total nitrogen content in seed was noted. Leucine content of seeds from infected plants was slightly less than from noninfected plants. Key Words: reniform nematode, soybean, inoculum levels, pathogenicity, resistance, susceptibility, population dynamics.

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