Effect of different growing media on morpho-physiological, biochemical and nutrient uptake characteristics of Amaryllis (Hippeastrum spp.) under vegetative growth period

Ideal plant cultivation substrates have become the first and most important prerequisite for the successful cultivation of any plant. One of the appropriate methods to achieve optimal performance and produce flowers with marketable quantity and quality is to use mineral and organic substrates as a substrate for growing ornamental plants. Today, in soilless cultivation systems, various inorganic and organic cultivation substrates are used worldwide. Not only good physical, chemical, and biological properties are important for a substrate, but a suitable culture medium must be available, relatively cheap, stable, and economically viable. Ornamental plant production worldwide has changed dramatically in the last 20 years. There are various reasons, including cheap labor and other initial costs, production has moved to new countries in Africa, Asia, and South America. Ornamental bulbous plants are herbaceous species that are morphologically characterized by regeneration structures located in underground storage organs, such as rhizomes, tubers, and bulbs. Amaryllis has a terminal inflorescence. The flowers are large and the colors vary with species, hybrids and varieties, but it varies from dark red to white, green and orange to mixtures. Amaryllis is produced commercially as cut flowers, pot plants, or propagation material (bulb), as well as gardening and landscaping. It produced as pot plant in Iran. Quality and quantity yield improvement of ornamental plants such as amaryllis is affected by genetic and environmental factors. Growing media is an agronomic factor. One of the important requirements in the production of horticultural products to achieve high yield and good quality, especially in the case of ornamental plants, is the plant cultivation media.

The growth of amaryllis (Hippeastrum spp.) was evaluated using different pot mixtures (v: v). This study was conducted as a completely randomized design with three replications in the Ornamental Plants Research Center (OPRC) in 2019-2020 on amaryllis. In this experiment, the applied treatments were included the type of substrate at 13 different levels,1) 80% perlite + 20% coco-peat,2) 60% perlite + 40% coco peat,3) 40% perlite + 60% coco peat,4) 20% perlite + 80% coco peat,5) 80% perlite + 20% peat moss,6) 60% perlite + 40% peat moss,7) 40% perlite + 60% peat moss,8) 20% perlite + 80% peat moss,9) 25% fine-grained perlite + 75% mixed perlite,10) 50% fine-grained perlite + 50% mixed perlite,11) 75% fine-grained perlite + 25% mixed perlite,12) 100% fine-grained perlite and 13) 100% mixed perlite. At the end of the experiment, Plant growth was measured by different parameters such as fresh and dry weight of shoots and root, leaf length and width, number of leaves, bulbs diameter, number of bulbs as well as nutrients uptake in the plant shoot were measured.

The results of variance analysis showed that there is a significant difference among substrates. It seems that the medium of 80% perlite with 20% cocopeat or 20% peat improves plant growth by absorbing more nitrogen, phosphorus and potassium nutrients. Therefore, the morphological characteristics of Amaryllis (Hippeastrum spp.) were also improved. 

Our findings indicate the relationship among media and improving the quantitative and qualitative characteristics of amaryllis (Hippeastrum spp.), which has been reported in other studies as well.