Cyanobacteria-based nutrimental strategy to enhance yield and quality of spinach

The intricate interplay of plant-soil-microbial formulations was explored using cyanobacterium-based mixes (Anabaena laxa C11, Nostoc carneum BF2 and Anabaena laxa RPAN8) as seed coating, followed by soil drench at selected growth stages in spinach (variety Pusa All green). A field experiment under shade net conditions was conducted and data recorded 2, 3, 5 WAS (Weeks after sowing) and harvest stage. Cyanobacterial treatments led to significantly higher pigment content (0.58-1.29-fold), along with substantial enhancement in the enzyme activities of nitrate reductase (0.33 - 0.49-fold), glutamine synthetase (0.35 - 0.53-fold) and phosphoenol pyruvate carboxylase activity (0.17 -0.38-fold) in leaves. RPAN8 treatment led to a notable increase in spinach yield, while BF2 treatment stimulated ascorbic acid (0.37-fold), antioxidants (0.36-fold) and β-carotene (0.41-fold) in fruits, over control. Overall, C11 treatment consistently exhibited significantly superior results in terms of growth, soil microbiological, yield and quality attributes. Principal Component analyses illustrated a strong positive correlation of fruit ascorbic acid with soil chlorophyll and available iron. Path coefficient analysis revealed positive direct effects of available nitrogen with PEPCo, nitrate reductase, chlorophyll a, carotenoids, leaf area and antioxidants at different sampling intervals. Such organic formulations can be a valuable resource-efficient strategy for improving spinach yield and quality.