Judul: Phalaenopsis sp. Growth Improvement through Nutrient Optimation.
Abstrak: Standard Operating Procedure (SOP) of Phalaenopsis sp. fertilization based on plant tissue analysis has not been developed in Indonesia. The basis development of SOP was executed on the two following research. The main research was conducted in the green house of Agropromo, Baranang Siang, Bogor and the supporting research was conducted in the green house in Gunung Batu, Bogor. The objectives of this study were (1) to establish the class of nutrient status of Phalaenopsis sp. (2) to study the optimation of nutrient concentrations (nitrogen, phosphorus, and potassium) applied through the leaves of Phalaenopsis sp., and (3) to study the Phalaenopsis sp. growth in the treatment of high concentrations of nitrogen, phosphorus, and potassium fertilizer with initial low pH conditions. The main research was aimed to find the class of nutrient status and optimize the nutrient of Phalaenopsis hybrid (Casablanca JDX x Diamond) # 1 x (Casablanca dream x self) #1. Plants were fertilized with N, P, and K in three separated experiments. The treatment were (1) 0, 65, 105, 157, 210 ppm nitrogen, (2) 0, 20, 40, 60, 80 ppm phosphorus, and (3) 0, 115, 230, 345, 390 ppm potassium. The results showed no effect of treatments on leaf water content, plant length, leaf area, stomatal density, leaf thickness, total chlorophyll content, anthocyanin content, and glucose content in all experiment. Nitrogen treatment produced significant effect on the increase in the number of leaves on 12 and 16 WAT (Weeks After Treatment), leaf greenness on 8 WAT, and leaf weight on 16 WAT. Phosphorus treatment produced significant effect on leaf greenness on 8 and 16 WAT, nutrient uptake on 16 WAT, and nutrient content in leaf tissue on 8 and 16 WAT. Potassium treatment produced significant effect on leaf dry weight on 8 WAT, nutrient content in leaf tissue on 8 WAT, and nutrient uptake on 16 WAT. Significant plant response was analyzed by polynomial contrast test. The class of nutrient status that could be set for nitrogen, phosphorus, and potassium treatment were very low, low, adequate, and high with the limit of nutrient content in the leaf tissue and leaf greenness in certain value. Nutrient optimation in nitrogen treatment was 89.33 ppm for leaf greenness on 8 WAT. Nutrient optimation in phosphorus treatment was 50.41 ppm for leaf greenness on 8 WAT. Nutrient optimation in potassium treatment could not be done because the variable of vegetative production (leaf greenness) was not significant in quadratic response. These results would be used as fertilizer recommendation. Before the main research, supporting research conducted to determine the limits of concentration and pH of the foliar fertilizer will be given. In the supporting research, we examined Phalenopsis amabilis accession “Trenggalek” responses at different pH of high concentration N (nitrogen), P (phosphorus), and K (potassium) fertilizer, in three separated experiments. Fertilizer was given at low pH (pH=2.5-4) and continued with neutral pH (pH=6.6), in high concentration which were (1) 431.417 ppm N (0-4 WAT); (2) 398 ppm P (0-2 WAT), 199 ppm P (2-4 WAT); and (3) 506 ppm K (0-4 WAT). No effect of treatments on
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