| Cut rose (Rosa cvs) is one of the most important flowers in the world flower market. The production area and the value of cut roses have occupied the first position in China recently. In spite of this the research on cut roses cultivation in China lags behind results in lower yield and poor quality of flowers. Most greenhouse production fertilize experimentally with excess fertilizer. Nutritional characteristics, diagnosis and fertilization of cut roses in computer-controlled greenhouse in Beijing area were studied in this dissertation. The results were summarized as follows:1. Container-grown rose cv 'Black Beauty' and 'Frisco' plants were irrigated 100ml every three days with complete nutrient solutions containing nitrogen at 10, 40, 80, 140, 200 and 300 mg/liter. Highest flower and biomass yield and best quality were consistently observed when roses plants receiving 140 mg /liter nitrogen. For 'Black Beauty' the annual flower yield is 22.20 per plant with stem length longer than 41cm, for 'Frisco' the annual flower yield is 22.93 per plant with stem length longer than 42.5cm. 10 and 300 mg /liter nitrogen fertilizer rates have effective negative on cut roses production. With optimum nitrogen fertilizer rates, auxiliary buds sprouting rates and the flowering rates were improved significantly and the number of basal shoots were also increased significantly. Furthermore, Nitrogen improved leaf photosynthetic and nutrient absorption significantly. Leaf total nitrogen, total phosphorus, total potassium concentration increased asymptotically with nitrogen application rates, while leaf total calcium concentration decreased and leaf total magnesian concentration had no significant difference.Nitrogen nutritional diagnosis was also studied. Quadratic relationship between the annual flower yield and leaf total nitrogen concentration of 'Black Beauty', the relationship indicated that highest yield possible during leaf total nitrogen concentration was 2.70%. The establishment of critical tissue total nitrogen levels for cut roses production has been based on lower 10% than that of highest yields, so critical upper bound tissue total nitrogen was 3.25%, lower bound was 2.14% in 'Black Beauty'. Two quick test methods for testing nitrogen were also studied. Leaf total nitrogen concentration was linearly and significantly correlated with leaf chlorophyll value measured by SPAD, but leaf nitrate correlated with leaf total nitrogen concentration insignificantly. The results ofpour-through test of media showed that highest EC were observed when irrigated with 10 and 300 mg/liter nitrogen.2. Similar experiments were designed in 'Black Beauty' grown with different phosphorus fertilizer rates (5, 10, 20, 40, 60, 90 mg/liter phosphorus per plant monthly) and potassium fertilizer rates (10, 40, 80, 160, 220, 300mg/liter potassium per plant monthly) respectively. The results showed 40mg/liter phosphorus application rate and 160mg/liter potassium application rate per a month were suitable for 'Black Beauty' growth. Quadratic relationship between flower yield and leaf total phosphorus concentration was observed, so was between flower yield and leaf total potassium concentration, Critical upper bound of leaf total phosphorus was 0.32%; lower bound was 0.20%, tissue total potassium were 1.83% and 1.18% respectively.3. The response functions of nitrogen, phosphorus and potassium fertilizer rates were obtained firstly in this dissertation, and regression responses were significant, so these models were used to nutrient diagnosis and fertilization management. Also with these models the maximum and optimum rates of nitrogen, phosphorus and potassium fertilizer rates for cut roses were calculated, the results indicates nitrogen fertilizer was more important because of its high rates. The fuzzy complex analysis of response of fertilizer for quality of cut roses were discussed because these quality parameters response of fertilizer differently, the results were N4>N3>N5>N2>N6>N1, P4>P5>P3>P6>P2>P1, K4>K5>K3>K6>K2>K1.4. Considering... |
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