Improving growth and productivity of cherry radish (Raphanus sativus L.) under sustainable treatments in a hydroponic system
Recycling fruit-processing residues as foliar bio stimulants may improve resource efficiency in hydroponic vegetable production. This study tested whether aqueous apple- and pear-peel extracts enhance the growth and productivity of cherry radish. The experiment was conducted at Research Station B, College of Agricultural Engineering Sciences, University of Baghdad, during the 2025–2026 autumn season. Five foliar treatments apple or pear-peel extract at 2.5 or 5 g/L and a distilled-water control were arranged in a randomized complete block design with three replications and applied three times to plants grown in a modified nutrient film technique system. Pear-peel extract at 2.5 g/L produced the highest leaf chlorophyll content (58.91 SPAD), leaf area (2.97 dm²/plant), leaf dry weight (0.40 g/plant), root yield (16.93 g/plant), and total yield (8.46 t/ha). Apple-peel extract at 2.5 g/L produced the greatest plant height (15.20 cm) and root length (6.40 cm), while the distilled-water control recorded the lowest values for most traits. Foliar application of dried pear- or apple-peel extract at 2.5 g/L can therefore improve cherry-radish growth and root yield while supporting the recycling of fruit residues in hydroponic production.