Research Papers: Influence of Inoculum Level and Temperature on Pathogenicity and Population Development of Lesion Nematodes on Soybean


  • N. Acosta


Glycine Max, Soybean Production, Tolerance Limit, Site of Inoculation, Seed Yield, Thermophilic, Tolerance


Greenhouse studies were conducted on the host-parasite relationships and the effects of temperature on pathogenicity and population development of lesion nematodes on soybean. Clark 63 soybean was a highly favorable host for Pratylenchus allem and P. scribneri. The degree of damage was influenced by initial nematode density and temperature. At a mean temperature of 29C, an initial inoculum level of 20,000 nematodes per pot significantly reduced shoot and root weights. Reductions in shoot and root weights were 45 and 49%, respectively, for P. alleni and 23 and 47% for P. scribneri when compared with noninoculated controls. Neither species affected plant weight at inoculum levels of 1,000 and 10,000 nematodes per pot. Soil temperature played a significant role in expression of damage by P. scribneri alone and only at relatively high constant temperatures. Stress on plants at 34C, reduced tolerance to this thermophilic species resulting in considerable growth reduction. Pratylenchus all