Organic Nutrient Strategies for Improving Growth Dynamics and Flowering in Coriander (Coriandrum sativum L.)

Organic farming, which enhances soil health through organic inputs like vermicompost and bio-fertilizers, is gaining prominence due to its eco-friendly nature and ability to improve crop yield. This study aims to assess the effect of organic manures on coriander's growth and seed yield and identify the best manure combinations to optimize production. The study was conducted during 2021–2023 in Sendurai village, Tamil Nadu, using a Randomized Block Design with 13 treatments replicated thrice. It evaluated the effects of vermicompost, sheep manure, cattle manure, and bio-fertilizers (Azospirillum and Azotobacter) on coriander growth and yield. Bio-fertilizers Azospirillum and Azotobacter were applied as per the treatment schedule at the time of sowing. Growth and seed yield parameters were recorded to assess the effects of organic manure and bio-fertilizers on coriander performance. The mean of five plants was taken for analysis. Among treatments, T4 (vermicompost @ 4 t/ha with Azospirillum and Azotobacter as soil application) consistently outperformed others, recording the shortest germination period (5.61 days), maximum plant height (78.62 cm), highest number of branches, largest leaf area (66.43 cm²), and highest chlorophyll content (4.56 mg/100 g). T4 also enhanced flowering and 50% flowering. The enhanced performance of T4 is attributed to improved nutrient availability and microbial activity. Overall, T4 proved to be the most effective treatment, significantly boosting growth and seed yield in coriander under organic nutrient management practices. The enhanced soil environment supports robust root proliferation, facilitating better water and nutrient uptake over a larger area. This improved nutrient absorption and translocation to different plant parts contributed to increased vegetative growth. The synergistic effect of Azospirillum and phosphorus-solubilizing bacteria, when applied with vermicompost and the recommended dose of fertilizers, was shown to advance 50% flowering. Overall, vermicompost with bio-fertilizers proved to be the most effective, offering a sustainable path to enhancing coriander productivity.