Author : Taweesak Viyachai

Summary : The effects of three different substrate volumes (34,73, 140 cm3) and three different substrates (coconut peat 100%, burnt rice husk 100% and coconut peat + burnt rice husk 50:50) grown at 64 plant/m2 were investigated. Plant height and the total leaf area of chrysanthemums reduced significantly when substrate volume decreased regardless of substrate type but chrysanthemum grown in substrate volume of 140 cm3 being produced at the highest plant height. Chrysanthemums grown in a substrate volume of 140 cm3 had the largest root surface area. The relative water content and macro elements in leaves did not differ significantly between treatments. Chrysanthemum grown in restricted root volume had high proline levels throughout growth period. Root:shoot ratio did not differ between treatments. plants grown in substrate volume of 140 ml showed the highest number of flower of 17.79 and flower diameter of 20.82 cm. The effects of two substrate volumes ( 73 and 140 cm3) and three irrigation frequencies ( 4,6,8 times/day) were investigated to determine a suitable irrigation frequency for the growth and flowering of cut chrysanthemum grown under restricted root volume. There was interaction between irrigation frequency and substrate volume on plant height of chrysanthemum. The tallest plant of 109.25 cm was obtained from chrysanthemum, grown at 140 cm3 irrigated 6 times/ day. Chrysanthemum irrigated 6 and 8 times/day had significantly higher phosphorus content in leaf than being irrigated 4 times/day. The total dry weight of chrysanthemum irrigated 6 and 8 times/day was higher than 4 times/day 32% and 23% consequently. Chrysanthemum irrigated 8 times per day had the highest number of flower, indicated at 20.44. In conclusion, chrysanthemum grown in substrate volume of 140 cm3 had better growth and flower quality than in 73 cm3. The growth and flowering of chrysanthemums irrigated 6 and 8 times/day were better than 4 times a day. The effects of two chrysanthemum varieties..