The Effects of Seed Aging and Plant Growth Promoting Bacteria (Pgpbs) on Seedling Emergance, Establishment and Yield of two Red Kidney Bean Cultivars

Use of plant growth promoting bacteria (PGPB) and high quality of seed as agricultural inputs play important roles in sustainable crop production. To study the effects of different levels of seed aging and PGPB's application on field emergence, seedling establishment and yield of two red kidney bean cultivars in field conditions, an experiment was carried out as factorial based in a RCBD design with 4 replications. Treatments consisted of four levels of seed aging [0 (control), 2, 4 and 6 days at 41°C with 90-100% relative humidity], four levels of bacteria inoculations [Control (no bacteria), Azospirillum lipoferum (strain of), Azotobacter chroococcum (strain 5) and Pseudomonas putida (strain 41)] and two bean cultivars (Akhtar and Sayyad). Results showed that the interaction effects of cultivar×seed aging×bacteria inoculation on seedling emergence rate (SER), final emergence percentage (FEP), seedling vigour index (SVI), 100 grain weight and pod number per plant were significant. The effects of bacteria inoculation on grain yield and interaction effect of cultivar×seed aging on emergence index (EI), mean emergence time (MET), grain yield and biological yield were significant. In addition, the EI was affected significantly by interaction effect of seed aging×bacteria. Grain yield, SER and FEP values followed by a declining trend as seed aging duration increased. The adverse effects of seed aging on these traits in Akhtar cultivar was more sever compared to Sayyad cultivar. High EI and SVI value obtained by Pseudomonas putida application. Use of bacterial inoculants particularly Azotobacter chroococcum and Pseudomonas putida improved grain yield compared to non-inoculated plants. In general, our results showed that seed aging decreased seedling emergence and grain yield of red kidney bean, however, the application of PGPBs could invigorate seedling growth, improved seedling establishment and amplified bean grain yield.