Eggplant (Solanum melongena L.) Growth and Physicochemical Characteristics of Coir Substrates Used for Hydroponic Cultivation

The goal of this study is (1) to determine the physicochemical characteristics of substrates according to their mixing ratios by grinding coir substrate used once in tomato hydroponics and mixing this material with perlite, and (2) to use the resulting material a hydroponic cultivation substrate for eggplants.The mixing ratios of the used coir and perlite on a volume basis were 70:30 (UC7P3), 50:50 (UC5P5), 30:70 (UC3P7), and 10:90 (UC1P9), with commercially available coir slab [dust: chip = 50:50(v/v)] and perlite slab (100%) used as control substrates.The total porosity was in the proper range of 89.6-95.6% for all substrates.However, the container capacity was highest in UC7P3 at 52.1%, and the air porosity was the highest in perlite at 58.2%.The air porosity rates of all treatments were high, and the container capacity was in the low range.The pH was in the proper range of 5.6 -6.1 for on all substrates except for the perlite cases, and the EC contents increased as the perlite content was decreased.The NO 3 -N, NH 4 -N, P 2 O 5 , Ca and CEC levels increased as the ratio of used coir increased, and exchangeable cations (K, Na, Mg) levels also increased as the coir ratio was increased.An investigation of eggplant growth results showed no certain trends among the mixed substrates, but the coir cases had the lowest plant height, SPAD, stem fresh and dry weight values.The fruit yield was highest in the UC7P3 and UC5P5 cases at 10.6, and the weight per plant, fruit diameter, and marketable were the highest in UC5P5.Therefore, when using coir substrates as hydroponic substrates, it is expected that the yield and marketable value will be better when adding perlite at a ratio of 50:50 (v:v).