Abstract:
Experiment on media suitable for culture of Dendrobium orchid seedlings were made by using banana homogenate, potato homogenate, and fish emulsion as basic organic components. A modified Schenk and Hildebrandt medium was used as control. It was found that mixing of banana or potato homogenate at a rate of 150 gram per liter or 4 milliliter per liter of fish emulsion with the modified Schenk and Hildebrandt basic components made the seedling grew approximately three times better than the ones in the control in four months. From aforementioned experiments, subtraction of each compound from the four compounds containing macroelements (magnesium sulphate, calcium chloride, ammonium phosphate and potassium nitrate) from the media was made. Serious deficiency symptoms developed only when potassium nitrate was omitted. Further investigations indicated that only nitrate not potassium was required for normal growth. Other three compounds could be omitted without any noticeable symptom. Therefore, the organic compounds used in the experiments did not contain enough nitrate nitrogen to support normal growth of seedlings. It was found that adding potassium nitrate or sodium nitrate at concentrations of 24.75 and 12.38 millimolar to the potato or fish emulsion basic media gave equally good results as adding all four compounds containing all macroelements, which the fresh weight of the seedlings were
Abstract:
approximately three times as the ones in control in four months. Similar treatments were made with banana medium yielded 2.2 times of the control. When omitting all microelements (including iron) in the potato or fish emulsion media, no sigh of deficiency were observed. Two new media, CU1 and CU 2, resulting from these experiments are proposed for culture of seedling and seed germination of Dendrobium and Cattleya orchids. CU 1 : 150 gram of potato homogenate, 12.30 millimolar of potassium nitrate or sodium nitrate, 40 gram of sucrose, 4 gram of agar and water to make 1 liter. This medium works best for both seedlings and seed germination of Dendrobium. CU 2 : the potato homogenate is replaced by 4 milliliter of Atlas Fish Emulsion Fertilizer and increases the amount of agar to 8 gram, all other components as CU 1. This medium is suitable for seed germination of Cattleya and also works well for both seedlings and seed germination of Dendrobium. Preparation of these media does not require analytical balance and PH meter which helps reduce cost and save time.