EFFECT OF MELOIDOGYNE INCOGNITA , PYTHIUM APHANIDERMATUM AND RALSTONIA SOLANACEARUM ALONE AND IN COMBINATIONS IN GINGER

Abstract

India is a major producer and exporter of ginger (Zingiber officinale Rosc.). The crop suffers serious losses due to several pests and diseases. Root-knot nematodes (Meloidogyne spp.) are important nematode pests of ginger. Rhizome rot/soft rot caused by pythium aphanidermatum and bacterial wilt caused by Ralstonia solanacearum (Pseudomonas solanacearum) are serious constrainsts in ginger production. Preliminary surveys indicated that the severity of these diseases was more in the presence of root-knot nematodes. A series of pot culture experiments were conducted to find out the individual and interactive effects of M.incognita in ginger. M.incognita caused 29.60 to 33.35% yield loss at Pi=0.2 to 2.0/100 cc. Soil though the nematode showed no role in the bacterial wilt, it had synergistic effect in rhizome rot/soft rot of ginger, particularly when nematodes were inoculated to the plants prior to fungi inoculation. The damage to the crop was more and the onset of the disease was early when M.incognita was inoculated 40 days prior to fungal inoculation.