Manipulating seed potato physiology, root dynamics, and productivity through organic and P nutrition application under semiarid conditions

Abstract

Improving seed‐size tuber productivity is vital for Punjab's seed potato ( Solanum Tuberosum L.) industry, which contributes nearly 60% of India's seed potato requirement. Field experiments were conducted during 2019–2020 and 2020–2021 at Ludhiana and Jalandhar to evaluate the effects of organic nutrient sources and phosphorus fertilization on seed potato physiology, root dynamics, yield, and quality. The experiment was laid out in a split‐plot design with organic nutrient sources (control, farmyard manure [FYM] @ 50 t ha ^{− 1} and biofertilizer @ 10 kg ha ^{− 1} ) in main plots and five phosphorus levels (0, 46.9, 62.5, 93.8 and 125 kg ha ^{− 1} P ₂ O ₅ ) in subplots. Application of FYM significantly enhanced tuber biochemical attributes, including ascorbic acid, protein, total sugars, starch, phenols, and chlorophyll content. FYM produced the highest tuber yield, recording increases of 28.2% and 29.9% at Ludhiana and 30.9% and 28.2% at Jalandhar over the control during 2019–2020 and 2020–2021, respectively. Similarly, the highest phosphorus level (125 kg ha ^{− 1} P ₂ O ₅ ) increased tuber yield by 21.9% and 24.4% at Ludhiana and 24.6% and 21.2% at Jalandhar compared with the unfertilized control. Enhanced root growth, haulm yield, and tuber quality attributes were also observed under FYM and higher phosphorus application. Principal component analysis revealed a strong positive association of tuber yield and quality traits with FYM and 125 kg ha ^{− 1} P ₂ O ₅ treatments. The results demonstrate that integrated use of FYM and adequate phosphorus fertilization substantially improves seed potato productivity and quality under semiarid conditions. Therefore, application of FYM @ 50 t ha ^{− 1} along with 125 kg ha ^{− 1} P ₂ O ₅ is recommended for seed potato growers to achieve higher yield and superior tuber quality in subtropical semiarid regions.