Cyanobacterium priming of tomato and spinach nursery stimulates seedling vigor and yields

Three cyanobacterial strains, Anabaena laxa C11, Nostoc carneum BF2, Anabaena doliolum BF4, producing plant growth promoting metabolites such as sugars, indole acetic acid and proteins were selected for priming seeds of three varieties of tomato and two of spinach, followed by nursery raising of seedlings in soil-less potting mixes. The performance of two tomato varieties NS2533 and NS4266, was superior, as compared to Jewel, with enhancement of 12% to 29% in terms of length and weight of root/shoots, as well as 76% more pigments. In tomato, Nostoc carneum BF2 was superior, closely followed by Anabaena laxa C11. Among the two Spinach varieties evaluated, Pusa All green responded with 15–20% significantly higher values of seedling traits, as compared to Mulayam. Vigor indices were significantly higher with the cyanobacterial priming treatments, with Anabaena laxa C11, showing 27% higher values, over control. Principal Component and Multivariate Analyses highlighted the significant correlation between chlorophyll and available N content of mix with biometrical and pigment-related attributes. Transplantation of best performing varieties of tomato -NS4266 and spinach -Pusa All green in climate-controlled polyhouse recorded significantly higher yields in the cyanobacterium-primed plants, over control. Such promising crop-cyanobacterium interactions can be explored for enhancing the productivity of nursery-raised vegetable crops.