Synergistic effects of optimized foliar calcium silicate spray and NPK fertilization on growth, flowering, stem mechanical strength and vase life in herbaceous peony.

In field-grown herbaceous peony (Paeonia lactiflora), 0.5 g L−1 NPK (19:19:19) combined with 0.5 g L−1 calcium silicate foliar spray produced the best growth and flowering quality.

• Why it matters: Inadequate agronomic practices in the Western Himalayan region of India limit cut flower spike quality and marketability, motivating optimized nutrient and foliar calcium strategies.
• What they did: Plants received soil-drenched NPK (19:19:19) at 0.5 or 1.0 g L−1 and foliar calcium chloride, calcium nitrate, or calcium silicate at 0.5 or 1.0 g L−1, then growth, nutrient uptake, stem strength, and vase life were assessed.
• The result: The optimized treatment improved photosynthesis, pigments, phenolics/flavonoids, N/P/K/Ca uptake, reduced stem bending via SEM-linked xylem secondary wall thickening, increased lignin deposition and expression of PAL, CAD, COMT, CCR, and POD, and prolonged vase life.