Background: Coincidence of heat with terminal stages of wheat is chief constraint to accomplish yield potential.
Objectives: The present study was aimed at comparing thermo-sensitivity of terminal stages, optimizing foliar potassium to alleviate heat and exploring association of metabolites with agronomic attributes.
Methodology: The experiment was laid out in randomized complete block design under split arrangement and repeated over two years. Treatments were comprised of heat stress imposition in main plots viz. H0 = No heat stress; H1 = heat imposition from spike initiation to grain filling initiation and H2 = heat imposition from flowering initiation to grain filling initiation and foliar potassium (K) in sub plots viz. K0 = Water spray (control), K15 = 15 g L-1 K; K30 = 30 g L-1 K; K45 = 45 g L-1 K and K60 = 60 g L-1 K.
Results: Imposition of ‘H1’ proved more deleterious for metabolites, water relations and agronomic attributes compared to ‘H0’ and ‘H2’. Application of 45 g L-1 K proved beneficial for enhancing the synthesis of phenolics, proline, soluble proteins and for improving water potential under ‘H0’. While, 60 g L-1 K induced more promising responses in these attributes under ‘H1’ and ‘H2’. Application of 45 and 60 g L-1 K proved equally effective for improvement of agronomic traits compared to other doses over H0, ‘H1’ and ‘H2’.
Conclusion: Decisively, more promising responses were observed with 45 g L-1 potassium under ‘H0’ and 60 g L-1 potassium under ‘H1’ and ‘H2’. Agronomic attributes were strongly associated with biochemical parameters.