BIOCONTROL OF A CHICKPEA ROOTROT DISEASE COMPLEX WITH PHOSPHATESOLUBILIZING MICROORGANISMS
Z.A. Siddiqui, M.S. Akhtar
The effects on chickpea (Cicer arietinum) of the phosphate- solubilizing microorganisms Aspergillus awamori, Pseudomonas aeruginosa (isolate Pa28) and Glomus intraradices in terms of growth, and content of chlorophyll, nitrogen, phosphorus and potassium and on the root-rot disease complex of chickpea caused by Meloidogyne incognita and Macrophomina phaseolina were evaluated. Application of these phosphate-solubilizing microorganisms alone and in combination increased plant growth, pod number, and chlorophyll, nitrogen, phosphorus and potassium contents, and reduced galling, nematode multiplication and root-rot index of chickpea. Pseudomonas aeruginosa reduced galling and nematode multiplication the most followed by A. awamori and G. intraradices. Combined inoculation of these microorganisms caused the greatest increase in plant growth and reduced the root-rot index more than individual inoculations. Pathogens adversely effected root colonization by G. intraradices. However, root colonization and root nodulation were increased when co-inoculated with P. aeruginosa and A. awamori whether in the presence or absence of pathogens.