Effect Of Different Water And Fertilizer Treatments On Biological Characteristics Of Yellow Dwarf Coconut At The Seedling Stage

This article took the Hainan yellow dwarf coconut seedlings as experimental material, using potted form, mainly studied the different water and fertilizer treatment on Hainan yellow dwarf coconut seedling; seedling physiological index in the change and analysised of plant nutrient content change. The experiment used3factors (water (W), N, P)3levels orthogonal design, a total9treatments. The main results are shown as follows:1. Effect of the appearance index of yellow dwarf coconut at the seedling stageWater significantly promoted the coconut height and stem diameter increase, reached significant level. Excess fertilization (N3P3) can inhibit the coconut growing under water stress condition (W1) and fertilization (N2P2) can alleviate the inhibition of coconut seedlings under W1condition. Plant height and stem diameter growth were positively related with nitrogen fertilizer application amount, when water treatment was W3. Effect of nitrogen fertilizer was more than phosphate fertilizer. Nitrogen fertilizer applying was beneficial to coconut growth. W3N3P2treatment was the highest increment in all treatments,3.3cm. Therefore, W3N3P2was the most beneficial to the yellow dwarf coconut growth.2. Effect of the physiological index of yellow dwarf coconut at the seedling stageWater was the biggest factor to affect the physiological index in leaves, followed by nitrogen. When water treatment was W1, chlorophyll content, relative water content reduced, MDA, relative electrical conductivity, proline and soluble sugar content rose; effect of nitrogen fertilizer to proline content was obviously(F=30.150, Pr> F<0.0001), reached extremely significant level. It was good to the accumulation of proline; when water treatment was W2or W3, chlorophyll content, relative water content increased, and nitrogen fertilizer applying was beneficial to the content increasing. Effect of phosphorus was not obvious. W3N3P2was the most beneficial to the yellow dwarf coconut growth.3. Effect of the Enzyme activity of yellow dwarf coconut at the seedling stageWi treatment influenced POD and SOD activity greatly, and in this level, effect of nitrogen and phosphorus were not obvious; when water level was W2or W3, nitrogen and phosphorus fertilizer promoted POD and SOD activity, phosphate fertilizer effect slightly higher than nitrogen. With high nitrogen and phosphorus treatment(N3P3), CAT activity was significantly lower than that in N2P2and N1P1 treatments under water stress condition(W1). On W3level, CAT activity was the lowest. W3N3P2was the best treatment.4. Effect of the N,P content of yellow dwarf coconut at the seedling stageNitrogen absorption and water level had a very close relationship. When applied the same quality of nitrogen fertilizer, W1treatment total nitrogen content in leaves was significantly lower than W3treatment; on W3level, W3N3P2treatment total nitrogen content was the highest,1.440mg/g, the most favorable for yellow dwarf coconut leaves total nitrogen accumulation. Effect of phosphorus for total nitrogen content was not significant. Phosphorus absorption quantity and water level were closely linked too, and had relationship with phosphorus fertilization amount. On W3level, nitrogen fertilizer promoted the leaves total phosphorus content increase. W3N3P2treatment was the most advantageous for yellow dwarf coconut leaves total phosphorus accumulation.