IMPROVING WHEAT GROWTH AND PHYSIOLOGICAL EFFICIENCY WITH FOLIAR AUGMENTATION OF POTASH

Abstract

Potassium (K) is an indispensable macronutrient that regulates plant growth, improves stress tolerance and boosts crop yield. A pot culture research was conducted at the Agriculture Research Institute, Dera Ismail Khan, during the 2022–2023 growing season to estimate the special effects of foliar-applied potash (K₂O) on wheat growth and yield. Treatments comprised 0 (control), 1%, 2%, 3%, and 4% K₂O applied at the tillering and booting stages. Results showed that 3% K₂O significantly enhanced plant height (85.3 ± 2.1 cm), tiller count (4.5 ± 0.3 plant⁻¹), LAI (3.4 ± 0.2), chlorophyll content (46.7 ± 1.5 SPAD), photosynthetic rate (16.2 ± 0.5 μmol CO₂ m⁻² s⁻¹), transpiration rate (4.5 ± 0.2 mmol H₂O m⁻² s⁻¹), stomatal conductance (0.35 ± 0.02 mol H₂O m⁻² s⁻¹), biomass accumulation (36.5 ± 1.8 g plant⁻¹), and grain yield (14.8 ± 0.9 g plant⁻¹). However, at 4% K₂O, insignificant reductions were experiential in some parameters, signifying that excessive potassium application may have antagonistic effects. The results indicate that 3% K₂O is the optimal concentration for improving wheat productivity under controlled conditions.