Effects of Different Irrigation Amounts and Vermiculite Laying Modes on Poinsettia Water Consumption Characteristics and Water Use

摘要

Two irrigation treatments (W1, total irrigation amount was12L.W2, total irrigation amount was 6L) and three vermiculite laying methods (Z0, no vermiculite. Z2, vermiculite was laid on the surface of the pot.Z2, vermiculite was laid in the bottom of the pot) were designed in the trial. The results showed that, the number and percentage of red leaves significantly decreased by 27.03%,16.00% in Z2 treatment than Z0 when irrigation amount was W1, respectively. The number and percentage of red leaves respectively increased by 6.49%,0.60% in Z2 treatment as compared to Z1 when irrigation amount was W2. Diurnal variation of evapotranspiration and transpiration of poinsettia showed a single peak curve, and the maximum were all occurred at the period of 14:00-16:00. The mass of dry matter (roots, stems) and the number of red leaves had a slight fall (no obvious difference) on the premise of saving 50% irrigation amount in W2Z2 treatment than W1Z0, the total dry mass and evapotranspiration were all evidently decreased, while irrigation water use efficiency was significantly uplifted by 72.36%. Therefore, W2Z2 treatment was the optimal combination mode which was not affected appreciation of the plants and meanwhile conducive to uplift for irrigation water use efficiency of potted poinsettia under the condition of the trial.