Study On Irrigation Index Of Muskmelon Seedling Nursery In Medium

Using the basic theory and technical methodology of crops irrigation and water research, aiming at short of quantitative, precise research data of water management in seedling nursery in medium, the paper analyzed morphology and physiological index and discussed water requirement of muskmelon in seedling stage to give basic theoretical data in irrigation management of muskmelon seedling production. The main results were as followings:1. Stem diameter, leaf area, index of seedling growth tendency and dry matter accumulation reached the highest point in treatment in which irrigation upper limit is 80%. With this treatment, the dry matter distribution proportion of shoot and root were in good coordination.2. There were two peaks in the curve of diurnal variation of net photosynthetic rate of muskmelon leaves and there was apparent midday depression. There were difference in net photosynthetic rate among different water content treatments and the difference between treatment B and other treatments were in significance anytime in a day. Irrigation upper limit at 80% would be beneficial to synthesis of chlorophyll and photosynthesis.3. Diurnal variation of transpiration appeared conic relation, water use efficiency's sequent order were treatment B > treatment C > treatment D > treatment E > treatment A4. The roots vigor of muskmelon seedling and their differences rised as seedling growing. The content of proline presented different variation tendency: the content of proline of treatment D and treatment E increased as the seedling growing, an the content of treatment A.B and C decreased as the seedling growing.5. The water requirement sum maturated practically of muskmelon was in good relevance with evaporation sum of the evaporation dish. The water requirement coefficient of muskmelon in seedling stage divided three different stages. Water requirement coefficient was low which would keep in the range of 0.862-0.903 before first leaf appearing. Water requirement coefficient would increase greatly to 1.214 between first leaf stage to second leafstage; in the third leaf stage the coefficient increased to 1.325.6. The relative water content, water potential in medium and the weight of the plug were in good linearity relation, the correlation coefficient reached 0.998.In seedling nursery, weighing the plug could control the water content in medium.7. Irrigation upper limit 80% was recommended for the optimal irrigation scheduling in seedling nursery in medium of muskmelon.