Effect of weight-based fertigation on physiology, gas exchange and yield of soilless cucumber and capsicum

Effective fertigation management through automation is crucial for enhancing yield and irrigation water use efficiency (IWUE) under soilless cultivation. This study evaluated weight-based fertigation strategies for automated fertigation control in cucumber and capsicum crops grown in coco-peat grow bags under semi-controlled greenhouse conditions. Four fertigation strategies were investigated based on weight change criteria: T1- 100% nutrient solution (NS) replenished to compensate for 200 g weight loss due to crop evapotranspiration; T2, T3, and T4 received 10%, 20%, and 30% less NS than T1, respectively. Growth parameters (plant height, leaf area, specific leaf area, leaf weight ratio, relative and absolute growth rates), and gas exchange parameters (photosynthetic rate, transpiration rate, and water use efficiency) were analysed. Results showed that T1 fertigation strategy significantly enhanced crop growth, photosynthetic activity, and yield. The highest yields were recorded for cucumber (101.20 t ha⁻¹) and for colored capsicum (61.13 t ha⁻¹) in T1 treatment. Reduced nutrient solutions treatments led to decreased yields but increased IWUE. Thus, the findings suggested that applying a higher level of the nutrient solution against weight loss offers the most effective approach. This weight-based fertigation approach may be prioritised for automated fertigation application and controls in coco-peat grow bag cultivation.