Response of saffron to some bacteria and mycorrhiza

This study examines the impact of various bacterial types and mycorrhizal fungi on the growth and chemical composition of saffron (Crocus sativus L.) cultivated in calcareous soils of Iraq. Inoculation with Azospirillum brasilense increased daughter corm weight by 58 % compared with the control, followed by Pseudomonas aeruginosa (29 %). At the same time, Bacillus megaterium and Azotobacter chroococcum reduced growth. Combined bacterial inoculation resulted in a modest 12 % increase, while Glomus mosseae alone slightly decreased daughter corm weight (6 %). The interaction of G. mosseae with A. brasilense produced the highest improvement (65 %). The number of new corms doubled with P. aeruginosa but declined under mixed bacterial treatments due to competition. Parent corm dry weight rose with A. brasilense (9 %) and A. chroococcum (8 %), while B. megaterium reduced it by 38 %. Mycorrhizal inoculation enhanced parent corm dry weight by 40 %, with an additional 21 % increase when combined with bacteria. Leaf biochemical analysis showed higher nitrogen, phosphorus, and iron levels under microbial treatments, with G. mosseae notably enhancing phosphorus (5.39 mg/g). Potassium content was unaffected by microbial interactions. These results demonstrate that biofertilizers improve saffron growth, nutrient uptake, and metabolite accumulation, supporting its successful and economically viable cultivation in calcareous soils.