Coir, an Alternative to Peat—Effects on Plant Growth, Phytochemical Accumulation, and Antioxidant Power of Spinach

The effects of four commercial substrates, a peat-based substrate, and three coir types (coir pith, chips, pith + fibers) on yield, phytochemical accumulation, antioxidant activity were evaluated in Spinacia oleracea L. cv. ‘Manatee’. Soil-blocked spinach seedlings transplanted into Styrofoam planting boxes filled with the substrate. Each box was irrigated daily by drip complete nutrient solution, irrigation scheduling optimized to peat. Leaf area fresh yield fiber similar those obtained However, shoot dry weight accumulation leaf chlorophyll lower plants grown coir. Substrate type did not affect carotenoids. Total flavonoid content higher different phenols (DPPH) pith. This indicates that types, mainly may provide an alternative peat since they allowed high be reached total flavonoids increased. In contrast, levels other phytochemicals usual for spinach. further research is necessary analyze solution adjusted each growing medium accumulation.