Effects of Meloidogyne incognita, Fusarium oxysporum f.sp. pisi, Rhizobium sp., and different soil types on growth, chlorophyll, and carotenoid pigments of pea

摘要

The effects of M. incognita, F. o. f.sp. pisi, Rhizobium sp., and different soil types on growth and chlorophyll and carotenoid pigments of pea were examined in single, simultaneous, and sequential inoculations. Soil with a 3:1 (v:v) clay:sand ratioproduced the most plant growth and the largest concentrations of chlorophyll and carotenoid pigments when compared with the other soil types. M. incognita and F. oxysporum alone caused similar reductions in plant growth and concentrations of chlorophylland carotenoid pigments while inoculation of the latter pathogen induced wilt symptoms. M. incognita and F. oxysporum interacted to show severe wilt symptoms compared with F. oxysporum alone. In single inoculation, Rhizobium sp. increased plant growth and chlorophyll and carotenoid pigment concentrations while its inoculation with pathogens reduced damage caused by them. Inoculation of Rhizobium sp. prior to pathogens was more effective in reducing damage than simultaneous inoculation. Inoculation of the pathogens prior to Rhizobium sp. resulted in more damage than simultaneous inoculation. F. oxysporum and Rhizobium sp. decreased nematode multiplication. The severity of wilt disease was greatest in a 1:3 and 0:4 clay:sand ratio and least in a 3:1 cla