EFFECT OF VARIOUS TYPES OF GROWING MEDIA AND APPLICATION OF LIQUID ORGANIC FERTILIZER ON THE GROWTH OF DENDROBIUM ORCHIDS

This research was a potted experiment carried out in a special orchid house (arnet) at the Padang Galleria Padangsambian Kelod from September to November 2019, the aim was to determine the effect of plant media and the provision of liquid organic fertilizers on the growth of dendrobium orchids. The factorial CRD pattern was the design used in this study, which consists of two factors, first, the use of growing media of wood charcoal (K), fern stems (P), and a mixture of fern stems with wood charcoal (M) and, second, the provision of liquid organic fertilizer, namely, Dewa (D), DI Grow (I), and GDM (G). The results showed that the interaction between the use of planting media and the application of liquid organic fertilizer had no significant effect on all plant growth parameters such as plant height, number of leaves, and number of tillers. However, the plant medium as a single treatment had a significant effect on the number of orchid tillers, fern stems (P) as the plant medium gave the highest number of tillers, namely: 2.22 stems or 32.93% more than the growing media for wood charcoal (K) and a mixture of charcoal, wood and fern stems (M) with 1.67 tillers each


INTRODUCTION
Cultivating orchids is quite easy, as long as they are properly cared for, they can grow in various climates. Orchids can grow from the lowlands to the highlands, because of variety of orchid species (Zhang et al., 2015). There are quite a lot of orchid plants that have been developed in Bali in particular and in Indonesia in general. Indonesia has about 3500 species of orchids resulting from interbreeding (Yulia et al., 2011). The most common type is Dendrobium, because this type has many colors and is relatively easy to maintain (Biswas et al., 2019, Naik et al., 2014 The orchid plant is an epiphyte plant, which lives by only taking parts of other plants that have decayed (Mondragon et al., 2015, Yong et al., 2014. Only a small proportion of orchids grow on the ground and are in dire need of high humus. Seeing this characteristic, it does not require a large area to work on it, so it is possible to cultivate it in the yard in urban areas which is often referred to as urban farming (Guitart et al., 2012, Malhotra, 2013 Silva et al., 2017, Trimanto & Rahadiantoro, 2017, Hariyanto et al., 2019.
Adequacy of nutrients accelerates the growth of orchids and the continuity of flowering (Naik et al., 2017, Herastuti & Hardiastuti, 2020.
Fertilization of orchids can be done by giving planting medium or spraying all over the plant (Samseemoung et al., 2017). Fertilizer given to the planting medium is usually in the form of liquid spray so that the nutrient supply is filled slowly. Orchids need to be fertilized once a month with fertilizers which contains N, P, K, Ca nutrients and other micro elements (Trepanier et al., 2008, Hapsoro et al., 2018, Zulfita et al., 2019. Fertilizers that are completed with micro nutrients, both artificial and organic fertilizers are quite widely available in the market. Liquid organic fertilizer can be applied by spray or sprinkled on the planting medium (Madusari, 2019, Fahrurrozi et al., 2019. The growth of Dendrobium orchids is largely determined by the appropriate planting medium and condition (Naik et al., 2014).
Criteria of good planting media are not easy to rot, plant roots are easy to stick, had enough cavity for air circulation, can store nutrients, and not easily become a source of disease.
Planting media can be in form of wood charcoal, fern roots, broken tile or brick.
The development of orchids has a lot of benefits. It can be used as a commodity for ecotourism, urban tourism and to increasing the income of farmers and communities.      However, in Table 2, it can be visually explained that the KI combination treatment shows the highest number of leaves, namely 8.33 strands, followed by PI with 7.67 strands, PG with 7.00 strands, PD is the same as MG with 6.67 strands, MD with 6.33 strands, MI was the same as KD with 6.00 each and the lowest was in KG as many as 5 strands.

Results
In combination, as shown in Table 3 The ability of ferns to bind and store water makes it easy for ferns to absorb fertilizer liquid that is sprayed so that it adds to the nutrient content planting medium so as to spur growth and emergence of tillers. Ferns contain sugar, amino acids, aliphatic acid and ester constituents needed by orchids. Fern growing media also has the advantage of not being easy weathered so that the plants can absorb the nutrients contained in a longer period of time.
The number of orchid tillers as a growth response to the growing media for wood charcoal (K) and mixed media (M) was lower than that of fern growing media (P) presumably because the wood charcoal is less porous so that the aeration and media drainage is not good, also the water holding capacity and the nutrient content are lower.