Geospatial Assessment of Chilling Requirements for Temperate Fruit Cultivation in Meghalaya, India

Abstract— Chilling hour (CH) accumulation is a critical climatic factor influencing dormancy release and flowering synchronization in temperate fruit crops. In this study, the spatial variability of chilling hours across Meghalaya, a northeastern hill state of India, has been assessed to evaluate the agro-climatic suitability for seven temperate fruit crops: apple, apricot, kiwi, persimmon, blueberry, peach, and walnut. Using ERA5-Land hourly gridded temperature data (9 km resolution), average annual CH accumulation was calculated over a 20-year period (2003–2023). The state was stratified into seven chilling hour zones based on cumulative CH thresholds relevant to crop-specific chilling requirements, determined in consultation with the Department of Horticulture, Government of Meghalaya. Results revealed that 55.33% of the state receives <100 CH annually, rendering these areas unsuitable for most temperate crops. However, higher-elevation districts such as West Khasi Hills and East Khasi Hills exhibit favorable chilling regimes, supporting the potential cultivation of low- and moderate-chill crops. Suitability analysis indicates that peach (CH >100) has the highest spatial suitability (45.25%), followed by blueberry (150–600 CH; 33.04%), kiwi and persimmon (CH >200; 28.98% each), apple and apricot (CH >300; 21.52% each), and walnut (CH >600; 4.00%). The study provides the first comprehensive chilling hour-based agro-climatic zoning for Meghalaya and presents a scalable framework for site-specific temperate horticultural planning in subtropical highland regions. The findings support the horticulture department of the state in decision-making for varietal selection, land-use allocation, and horticultural diversification under changing climate scenarios.