Initial inoculum concentration of nematode Heterodera glycines affecting the development of common bean

Abstract

To determine the effect of inoculum concentration on the patogenicity of Heterodera glycines to the
commom bean plants (Phaseolus vulgaris L.) cultivar Ouro six concentrations (0, 1,200; 2,400; 4.800; 9,600 and 19,200 eggs/plant) were tested in comparison to soybean cultivar FT-Cristalina. On common beans the largest yield reduction was 14,9% when inoculated with 5,600 eggs/plant. There was a reduction of 40,8% in the root dry weight at the level of 12,600 eggs/plant. The chlorophyll content and the amount of phosphorous, potassium, iron, manganese, zinc and copper did not differ with inoculum concentration. On soybean the largest reduction in grain production was 84,1% when the concentration was 19,200 eggs/plant and the largest reduction in the root weight was 46,8%.