Introduction of a Suitable Cultivation Substrate for the Optimal Growth of the Ornamental Plant Crassula capitella

The properties of different materials used as planting substrate exert direct and indirect effects on crop growth and production. Hence, the selection of a suitable substrate is one of the most important factors in the success of production in soilless cultivation. The present study aimed to investigate the effects of physical and chemical properties of different cultivation substrates on the growth and development of Crassula capitella. Thus, different organic and inorganic cultivation substrates such as sand, coco peat, charcoal, pumice, peat moss and zeolite were combined with each other in different ratios and tested. The measured traits were phytochemical compounds (chlorophyll a, b and total, carotenoid, supeoxide dismutase (SOD) activity level and malondialdehyde (MDA) content), fresh weight and dry weight of root and shoot, and element uptake (nitrogen, phosphorus and potassium). Based on the results of the present research, there was a significant difference in terms of plant height, wet and dry weight, nutrient uptake rate and enzyme activity between different cultivation substrates. The plants grown in substrate (35 cm^3 of fine pumice + 5 cm^3 of coco peat + 5 cm^3 of peat moss + 5 cm^3 of charcoal) and substrate (35 cm^3 of 3-5-mm fine sand + 5 cm^3 of coco peat + 5 cm^3 of charcoal) showed the highest and lowest numerical values of the evaluated traits, respectively. The use of combinations containing pumice, coco peat and zeolites seems to prevent the wastage of nutrients and preserves nutrient ions, and therefore results in increasing the fertilizer efficiency and improving the nutrient uptake and maintaining moisture, and ultimately improves the plant growth.