Organic Waste-Based Plant Sunscreen Spray for Mitigating Heat Stress and Sunburn in Crop Plants

Rising temperatures and prolonged solar radiation pose serious threats to agricultural productivity, causing leaf scorching, reduced photosynthesis, and significant yield losses. This study presents the development and field evaluation of a bio-waste-derived plant sunscreen spray formulated from banana stem powder, fruit peel powder, used tea waste, and aloe vera gel. The bio-waste ingredients were sun-dried, ground into fine powders, and subjected to controlled hot-water extraction to release bioactive compounds including tannins, polyphenols, flavonoids, pectin, and antioxidants. Filtered extracts were concentrated and blended with freshly prepared aloe vera gel to produce a stable, film-forming foliar spray. The formulation was applied to potted tomato and chilli plants maintained under natural outdoor conditions over a sixty-day observation period, with untreated plants serving as controls. Treated plants consistently exhibited lower leaf surface temperatures, healthier foliage, reduced sun-scorch symptoms, and improved canopy development compared to untreated controls. Temperature measurements confirmed a progressive reduction in leaf surface temperature in the treated group, with differences widening as sunlight intensity increased across the observation period. The spray coating persisted for several days without causing phytotoxic effects or interfering with normal plant growth. The formulation is low-cost, biodegradable, and prepared from widely available agricultural residues, making it a viable and sustainable protective solution for smallholder farmers in tropical and subtropical regions.