Interactions ofMeloidogyne incognita,Ascochyta rabiei,Xanthomonas campestrispv.cassiaeandRhizobiumsp. on the disease complex of chickpea

Abstract

Effects of Meloidogyne incognita, Ascochyta rabiei, Xanthomonas campestris pv. cassiae and Rhizobium sp. were examined alone and in combination on the disease complex on chickpea. Individual inoculation of M. incognita, A. rabiei and X. campestris pv. cassiae caused significant reduction in plant growth while inoculation of Rhizobium sp. resulted in a significant increase in plant growth over control. Inoculation of pathogens in combination caused a greater reduction in plant growth than the damage caused by each of them singly. Application of pathogens prior to Rhizobium sp. caused a greater reduction in plant growth compared to plants where Rhizobium sp. was inoculated prior to pathogens. Use of M. incognita/A. rabiei or X. campestris pv. cassiae with Rhizobium sp. reduced root-nodulation. Application of Rhizobium sp. prior to pathogens resulted in greater nodulation compared to plants where Rhizobium sp. was inoculated simultaneously with pathogens. Rhizobium sp., A. rabiei and X. campestris pv. cassiae had adverse effect on galling and nematode multiplication. Maximum reduction in galling and nematode multiplication was observed when Rhizobium sp. along with A. rabiei plus X. campestris pv. cassiae was inoculated prior to M. incognita. Fungal and bacterial blight indices were 4 where A. rabiei and X. campestris pv. cassiae were inoculated alone. In other treatments where these pathogens were used in combination disease indices were 5.