| In this paper, spraying treatment with plant growth regulators, the water-control bag and new technology of drip irrigation were applied to plants by two aspects: on the one hand, effects of plant growth regulators"Shifengle"on the growth and physiology of the plants was studied to probe the influence of the plant growth regulators on the promotion of seedling growth and drought-resistant of seedlings. On the other hand, drought-resistant and water-saving technology of water-control bag and new drip irrigation, which make the plant long-term survival and growth with small amount of water were discussed. The quantity of water required in the growth of seedlings was ensured. The objective of this study was to provide theoretic basis for effectively delaying drought stress on the seedlings, improving the situation of the plant and improving the survival rate of seedlings under the drought condition.Growth, characteristic of water physiol-ecology and transpiring-water consumption of Quercus variabilwas's has greatly influenced by the treatment with plant growth regulator. It has great promotion to the growth of Quercus variabilwas compared to the plants under normal treatment, whether spraying leaves or soaking roots. The diameter, height, leaf areas, net photosynthetic rate, water use efficiency and content of chlorophyll a and b was separately 11.56% to 245.07%, 58.01% to 434.66%, 28.52% to 432.13%, 2.95 % to 38.01%, 4.20 % to 23.68% and 5.19 % to 23.1 %greater than the comparison. Besides, weight of dry matter on and under the ground was also separately 10.71% to 78.27% and 11.39% to 40.45% greater than the comparison. But the transpiration rate was significantly lower. Generally speaking, suitable treatment should be selected in different circumstances as follows: If soaking roots was convenient, to soak roots with 10 mg/LGGR-6 or 20 mg / L "Shifengle" should be selected to cultivate strong seedlings, to soak roots yet with 20 and 40 mg/LGGR-6 or 20 mg / L "Shifengle" to cultivate drought-resistant seedlings; If spraying was convenient, it's suggested to spray the 20 mg/L to seedlings in the initial growth period and fast-growing period.The technology of water-control bag was used to the principle of non-energy-consuming which can provide water persistently to plants by pump. The results showed that the water-releasing quantity of water-control bag was mainly decided by three factors: the contact areas between tap and soil, the water requirement of the seedlings and soil water content. After 50 days, total water-releasing quantity of the three seedlings were respectively about 3345g (Robinia pseudoacacia), 2849g(Platycladus orientalis) and 2122g(Sophora japonica), and they were only 28.3%, 23.3% and 17.5% of water-releasing quantity in normal water supply. Leaf water potential between drought and normal watering by use of water-control bag, the soil water content of Robinia pseudoacacia,Platycladus orientalis and Sophora japonica were respectively maintained to 7.2% to 10.7%, 7.4% to 12.9% and 8.3% to 13.2%, while the comparison seedlings without water had been dead with soil water content of 3.2% to 4.0%. In the medium-term of the experiment, net photosynthetic rate of the seedlings subjected to drought stress was almost zero. At the same time, net photosynthetic rate of the seedlings with treatment by water-control bag was also significantly reduced with low photosynthetic rate persist in longer period. In the last term, water could be hold in the seedlings treated with water-control bag for a long time. Smaller stomata aperture could be maintained to make seedlings have photosynthesis and transpiration at a certain extent. Overall, water-control bag can maintain the water balance, good water conditions and high water potential in seedlings, which can decrease the degree of water stress, and keep growth of seedlings.The new drip irrigation technology, which control release of water by adjusting different height of water level, provide necessary volume of water for the plants. Growth and physiological characteristics of Populus tomentosa clone (shanxi) was taken for example, the diameter, height and leaf areas of the seedlings treated with this technology were markedly improved than drought ones. Their soil moisture content and leaf water potential were between normal and drought stress condition. Less, middling and more water was separately provided for the seedlings by treatment A (small amount of release water) than B (middling amount of release water) and C (more amount of release water). In the end of the experiment, soil water content of seedlings under A, B and C treatment was separately 4.1%, 8.97% and 10.54%, their net photosynthetic rate were separately 32.24%, 51.7% and 66% of the seedlings under normal water supply, and their transpiration were separately 31.78%, 53.64% and 51.53% of the normal seedlings. Water use efficiency of seedlings under A, B and C treatment were separately only 70%, 88% and 90% of the seedlings under normal water supply. Water-releasing amount could maintain certain level by the means of using drip irrigation technology. 8592 g, 14712 g and 22842 g were separately released by A, B and C treatment, which were separately 28.64%, 49.04% and 76.14% of those with normal water supply. Three kinds of treatments could make more progress in growth and physiology of Populus tomentosa clone (shanxi). In the whole experiment, about half of the normal water supply (14712 g was 49.04% of 30000g of normal watering amount) used in treatment B was used for watering which make the soil moisture content maintain 45% of the normal watered for seedlings. Net photosynthetic rate, water use efficiency and biomass of seedlings were separately 51%, 88%and 61.43% of the normal watered. Application of the new drip irrigation technology can not only make the seedlings grow normally, but also achieve the purpose of water-saving and drought resistant.
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