Host Efficiency of Potato to Meloidogyne incognita and Damage Threshold Densities on Potato

Abstract

Host efficiency of selected clones of Solanum tuberosum spp. andigena (TA) and of S. sparsipilum x (S. phureja x S. tuberosum) (SPT) for 3 geographically isolated populations of race 1 and one population of each of the other 3 races of Meloidogyne incognita was studied. All TA clones were efficient hosts for all populations, but efficiency of SPT clones varied. On efficient hosts of M. incognita, race 2 was more aggressive than the other races and reproduced under a wider range of temperatures. According to tuber weight at harvest and nematode reproduction 60 days after inoculation, one susceptible TA clone was tolerant to M. incognita. Under conditions of our experiment, the damage threshold density of M. incognita was 5 eggs/g of soil for a susceptible TA clone and 10 eggs/g of soil for a susceptible SPT clone.