Alleviating the salinity stress on strawberry using plant growth promoting micro-organisms

Strawberry is a surface feeder, herbaceous plant and considered as nutrient responsive, salt sensitive crop which requires judicious amount of nutrients, moisture for quality fruit production. Strawberry is traditionally grown in north eastern and western India including Gangetic plains. However, salt affected areas in southern and western India limits the further commercial area expansion under this crop. It has been reported that under salt stress the beneficial micro-organisms lead to alter the growth and development of strawberry plants by adjusting hormonal balance, enhancing nutrient status, solubilization of mineral phosphates, and producing plant growth regulators. An experiment was conducted at the Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal, India during 2020-21. The microorganisms and their combinations such as untreated control (T ₁ ), Azotobacter (T ₂ ), Phosphorous solubilizing bacteria (T ₃ ), Trichoderma (T ₄ ), Azotobacter  + Phosphorous solubilizing bacteria (T ₅ ), Azotobacter + Trichoderma (T ₆ ), Phosphorous solubilizing bacteria  + Trichoderma (T ₇ ), Azotobacter  + Phosphorous solubilizing bacteria  + Trichoderma (T ₈ ) were applied as soil drenching. The maximum growth characteristics was recorded with T ₁ (control) due to no salt stress condition. The soil drenching of Azotobacter  + Phosphorous solubilizing bacteria  + Trichoderma (T ₈ ) were found to be significantly most effective in increasing the plant height (11.96 cm), number of leaves per plant (5.80), shoot length (10.85 cm), root length (13.24 cm), shoot fresh weight (24.07 g), root fresh weight (6.42 g), shoot dry weight (4.59 g), root dry weight (1.01 g), leaf chlorophyll content (44.96 SPAD unit), number of crowns plant ^-1 (7.13), salt tolerance ratio (0.95), leaf nitrogen (1.64%), phosphorous (0.62%), potassium content (1.59%) and lowest sodium content in leaves was recorded with T ₁ (0.90%) followed by T ₈ (1.01%). The combined application of Azotobacter  + Phosphorous solubilizing bacteria +  Trichoderma showed positive results on plant growth, salt tolerance, phosphate solubilization and atmospheric nitrogen fixation under salt stress condition.