Unravelling the biochemical and phytochemical responses of sapota (Manilkara zapota L.) P. Royen cv. DHS-1 on foliar feeding of plant growth regulators

Foliar application of plant growth regulators (PGRs) is one of tactic for plant nourishment which directly enhances nutrient uptake, leading to a more balanced nutrient supply and improved accumulation in plant ultimately improving quality and yield. The current research covers to see the response of biochemical and phytochemical parameters of sapota cv. DHS-1; to the pre-harvest spray of the PGR i.e. naphthalene acetic acid (NAA) (50 and 100 ppm), 2-chloro-4-pyridyl) N'-phenyl urea (5 and 7.5 ppm), salicylic acid (SA) (150 and 300 ppm) and homo brassinolide (10 and 15 ppm); sprayed at flowering, pea stage and marble stage of plant growth. Treatments were imposed on 24-years-old, uniformly grown, sapota trees, planted at 10m x 10m spacing, at Central Horticultural Experiment Station, (ICAR-IIHR), Bhubaneswar during 2022 and 2023. In general, application of PGRs were foundaffecting the fruit quality significantly over control. However, application of NAA and CPPU performed better at higher dose. The treatment NAA at 100 ppm resulted in highest total soluble solids (°Brix), TSS: acid, ascorbic acid content, sugar content and minimum titratable acidity (%). Further, application of NAA at 100 ppm found to be most effective in boosting total flavonoids content, total phenol content and antioxidant activity. The possible correlations among these parameters were discussed which showed that the bio-active compounds such as vitamin C, phenol and flavonoid contributed towards the anti-oxidant capacity of fruit. Therefore, application of PGRs showed to effectively augment fruit quality by improving both biochemical and phytochemical properties when compared to control.