This study was conducted to investigate the effect of tilapia effluents on infectivity, development and reproduction of M. incognita and R. reniformis on five strains of cowpea and its impact on plant growth under greenhouse conditions. Unfertilized tilapia pond with complete diet (T4) was the best treatment which significantly reduced all M. incognita criteria (no. of galls, embedded stages, egg masses, build up and eggs/eggmass) on cowpea strains 1, 2 & 4. Biofloc tanks (T5) was significantly efficient on cowpea strain 3. Low organic fertilized tilapia pond (T2) reduced nematode criteria on strain 5 without significant differences in build up when compared with high inorganic fertilized tilapia pond (T1) & high organic fertilized tilapia pond (T3). On the other hand, T4 significantly reduced build up of R. reniformis on cowpea strains 1 & 4. T5 significantly decreased reniform nematode reproduction on strains 2 & 3. However, all treatments failed to reduce nematode criteria on strain 5. In general, all treatments ameliorated cowpea growth parameters and improved plant content of NPK except on strains 1 and 5. Integrating aquaculture-agriculture system(IAA) has an additional benefit which makes the fish waste and algae productions have the potential to decrease the nematode populations and improve plant growth.