Vol. 12, Issue 10 (2023)

Author(s):
B Sowmya, Dr. A Girwani, CNR Santhoshini, Dr. V Murali and B Chandra Sheker

Abstract:
The experiment entitled Improving the growth and flower yield of pot marigold (Calendula officinalis L.) under stress conditions varied water using bio inoculants was conducted during 2020-2021 with the objectives, to evaluate the effect of bio-inoculants on growth, water relations, plant pigments, flower yield of Calendula officinalis grown under different water stress regimes. The experiment was conducted in a split plot design with 4 main plot and 3 subplots with 12 treatments replicated thrice. The different water stress treatments used are WS₁ (Field capacity), WS₂ (75% Field capacity), WS₃ (50%Field capacity), WS₄ (25% Field capacity) and usage of different bio inoculants viz., AMF (Arbuscular mycorrhiza fungi), AMC (Arka microbial consortium) and control (no treatment). The treatments were imposed on the calendula crop variety “Bon Bon Orange”. The observations were recorded at an interval of 15, 30, 45, 60 DAP (days after planting). maximum plant height (15.56 cm) was recorded at 60 DAP in the treatments WS₂, maximum number of branches (6.32, 7.94 and 9.62) were noticed in all intervals under WS₁ stress regime and maximum branches (9.28) under AMF application, The interaction effects of water stress (WS₂) and bio inoculants have shown that the maximum number of leaves 119.8,137.67,143.27 with the treatment WS₂ x AMF at all intervals. maximum Leaf dry mass (2.98) under AMF application at 30 days interval. Maximum leaf area index was observed at 30 and 45DAP of14.95cm²/g, 17.41 cm²/g compared to AMC and control. maximum RWC (64.9) was recorded at 45 DAP and at 60 DAP (6.3) during AMF application in comparison with control and AMC. maximum leaf electrolyte leakage observed 60 DAP (300 dSm) under WS₄ regime. maximum Chl a recorded at AMF treatment (1.504 mg) at 30 DAP. Chl a content under interaction of WS₂ X AMF showed best results (1.589mg). Maximum SPAD values (183.76,193.13,225.33,300.17s) noticed under 15,30,45,60 DAP under no waters stress condition. maximum flower production WS₂ water stress regimes at all harvest intervals (39.33, 48.67 and 56.67) were recorded. Among bio inoculants application maximum is observed with AMF inoculation observed (38.25, 47.25, and 57). Maximum flower fresh bio mass recorded at 3^rd harvest and 19.62 g/plant at 4^th harvest. Maximum flower dry mass observed at WS₁ stress regimes (1.61 g/plant) following WS₂ (1.91 g/plant), WS₃ (1.13), WS₄ (1.07 g/plant). The results suggest that, main plot Treatment (WS₂) and in some cases WS₁ stress regimes and Bio inoculant AMF (20 g/plant) proved to be best treatment.