Pigeonpea was inoculated with 250, 500, 1 000, 2 000 and 4 000 Heterodera cajani second-stage juveniles (J2) in a glasshouse test. Pigeonpea growth and rhizobia nodulation progressively decreased as the inoculum level increased. Significant reduction in plant growth occurred with an inoculum of 500 or more J2 of H. cajani in both Bradyrhizobium japonicum-inoculated and noninoculated plants. Peroxidase activity was higher in H. cajani-inoculated plants with the highest level at an inoculum density of 500 J2. Nitrate reductase, catalase and chlorophyll content were reduced as inoculum levels of H. cajani increased. Chlorophyll content and enzyme activities were higher in B. japonicum-inoculated plants than in plants without B. japonicum.
