Evaluating the role of endophytic cyanobacterial isolates on growth promotion and N/P status of rice crop

Cyanobacteria have shown potential in promoting the health and growth of rice plants. A study was undertaken during kharif, 2018 to analyze the effect of two endophytic cyanobacterial strains isolated from the selected rice varieties on growth and yield of basmati (PB 1509) vis a vis non- basmati (Pusa 44) rice cultivars. The cyanobacterial strains namely C1 (a potential nitrogen fixer from rice variety IR 64) and C2 (an effective P solubilizer from rice variety Pusa 1612) belonging to Anabaena sp. were used. The field experiment consisted of control (T1) with recommended dose of fertilizer (RDF) along with four different combinations of fertilizer dose and cyanobacterial strains as T2 (RDF + C1); T3 (75% N in RDF + C1); T4 (RDF + C2) and T5 (RDF with 25% P as MRP and 75% P as SSP + C2), was conducted using split plot design with three replications. Treatments consisted of RDF alone (T1) without inoculum and inoculation with strain C1 with RDF (T2) and with 75% of nitrogen in RDF (T3). Strain C2 was used with RDF (T4) and with 25% P as MRP in RDF (T5). At 90 Days after Transplantation (DAT), the treatments T2 and T3 exhibited better response on per plant basis in terms of plant height (83.3 cm; 85.7 cm), dry weight of leaves (4.24 g; 4.79 g) and stem (13.2 g; 10.0 g) in basmati variety, while, treatment T4 showed better effect (75.3 cm) on plant height in non-basmati variety, which showed maximum dry weight of leaves (5.33 g) and stem (10.8 g) under treatment T5. However, number of tillers, panicle and grain weight per plant depicted variable results. Use of the cyanobacterial strains slightly enhanced N (0.5–1.8%) and P (1.3–2.3%) concentrations in plants at different stages of crop growth as well as at harvest stage.