Evaluating Fertilization Strategies in Potato Crop for Improved Productivity Under Agro‐Ecological Conditions of Pakistan

Potato is the main source of income for the growers of middle Punjab, Pakistan. Despite being a key cash crop, potato yields remain below potential, mainly due to inefficient fertilizer management in alkaline sandy loam soils, necessitating strategies that can enhance tuber yields. This 2‐year study aimed to enhance potato yield by optimizing fertilizer application strategies, comparing conventional synthetic phosphorus (P) and nitrogen (N) applications with plant growth–promoting bacteria (PGPB)–coated biofertilizers. Potato cv. Sante was evaluated under three treatments: four split applications of synthetic P:N (185:250 kg ha −1 , control) fertilizer, six split applications of synthetic P:N (185:250 kg ha −1 ) fertilizer, and six split applications of PGPB‐coated P:N (185:250 kg ha −1 ) biofertilizer. Results showed that increasing the number of split applications improved all growth attributes. The highest performance was recorded with PGPB‐coated biofertilizers, which enhanced intercellular CO 2 concentration by 91.6%, photosynthetic rate by 8.9%, and water use efficiency by 37.4% to the control, while reducing stomatal conductance and transpiration rate by 15.5% and 20.6%, respectively. Although photosynthetic rate correlated weakly with total yield, it showed a moderate relationship with rashan‐grade yield. Overall, PGPB‐coated P:N (185:250 kg ha −1 ) biofertilizers applied in six splits significantly improved total and rashan‐grade yields while minimizing downgrade yield. These findings support the use of PGPB‐coated biofertilizers as an eco‐friendly and efficient strategy for boosting potato productivity.