The Effect of Keratin Hydrolyzate Peptide Concentration and Harvest Maturity Level on the Physiological Response and Physicochemical Quality of Siam orangess (Citrus nobilis Lour.)

Putu Bujangga Wahyu Kharisma Putra; I Nyoman Rai; Ni Nyoman Ari Mayadewi

doi:10.55927/fjst.v5i9.160

Authors

Putu Bujangga Wahyu Kharisma Putra Master’s Student in Agrotechnology, Faculty of Agriculture, Udayana University, Jl. P.B. Sudirman, Denpasar, Bali
I Nyoman Rai Laboratory of Agronomy and Horticulture, Faculty of Agriculture, Udayana University, Jl. P.B. Sudirman, Denpasar, Bali
Ni Nyoman Ari Mayadewi Laboratory of Agronomy and Horticulture, Faculty of Agriculture, Udayana University, Jl. P.B. Sudirman, Denpasar, Bali

DOI:

https://doi.org/10.55927/fjst.v5i9.160

Keywords:

Siam Oranges, Keratin Hydrolyzate Peptide, Biostimulant, Harvest Maturity, Physicochemical Quality.

Abstract

This study evaluated the effects of Keratin Hydrolyzate Peptide (KHP) concentration, harvest maturity, and their interaction on physiological and physicochemical traits of Siam oranges. A 3 × 3 factorial randomized complete block design with four blocks (36 trees) was conducted in Kintamani from October 2025 to May 2026. KHP was foliar-applied at 0, 2, and 4 mL L⁻¹. The 2 mL L⁻¹ treatment increased relative leaf water content, chlorophyll, TSS, and fruit weight. Harvest maturity affected vitamin C, TSS, TA, TSS:TA ratio, and fruit weight. P₂M_p produced the highest total fruit moisture content (88.72%). Multi-season and multi-location validation is required before broader recommendation

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