A few days ago, the rose blossomed very well. Suddenly, the leaves began to turn yellow, and they fell one after another with a touch. What should I do? Should I take it out to see the sun, or is it because there is too much water? Maybe many people will encounter this situation. Now Xiaobian will analyze the cause of the yellow rose flowers and how to deal with it.
Rose leaves yellow
Let's first look at the growth habits of rose flowers:
Although rose has not strict requirements on climate and soil, loam with loose, fertile, rich in organic matter, slight acidity and good drainage is suitable. It likes warm, sunny and airy environment. The optimum temperature of most varieties was 15-26 ℃ in the daytime and 10-15 ℃ in the evening. In winter, when the temperature is lower than 5 ℃, it will enter into dormancy. Some varieties can endure - 15 ℃ low temperature and 35 ℃; when the temperature lasts over 30 ℃ in summer, they enter into semi dormancy, and the plants grow poorly. Although they can also conceive buds, they have few small petals, dim and lusterless colors, and lose their ornamental value. Cause analysis and treatment of yellow leaves of Chinese rose
Performance: its performance is yellowing and falling off of leaves, withering of branches, rot of some roots, and smell of distiller's grains.
Treatment method: for the seriously injured plants or waterlogging that are difficult to be eliminated, they should be cut again and dug up, and then planted after raising the terrain. For the lightly injured, the method of piling soil at the base of the plants can be used to stimulate the root neck to produce adventitious roots, so as to alleviate the problem.
Cause 2: diseases and insect pests
Performance: leaf spot diseases and powdery mildew caused by fungi cause a large number of leaves to fall off, which affects the formation of flower surface. In serious cases, the leaves can not carry out photosynthesis and die.
Treatment method: the bacteria began to be infected from the end of May to the beginning of June, and the high temperature and rainy season from July to August was the peak. From the end of May, spray Baume 0.3 to 0.5 degree sulfur mixture once a week for 2 to 3 times in a row. From July to August, if there is a serious outbreak sign, spraying 40% formis WP 500 times, once a week, three times in a row, can effectively prevent and control. If there is much rain, the spraying times shall be increased accordingly. Longicorn beetle is the most serious pest. It is one of the key measures to control longicorn by cutting off the branches damaged by longicorn larvae from the middle of June to July. If this link is not caught and the larvae get into a trunk, it will increase the difficulty of control. Check the tree body before and after autumn equinox and Qingming, inject 5 to 10 times of 80% dichlorvos emulsion into the wormhole, and then seal it with mud to kill the larva of longicorn. As soon as other leaf eating pests are found, they can spray 800 times of long-acting phosphorus agents, kill eggs and larvae, and effectively control leaf eating pests.
Reason 3: improper fertilization
Performance: few flowers, small flowers and thin branches are the performance of lack of fertilizer.
Treatment method: according to the lack of elements, supplement fertilizer, and apply other elements fertilizer to improve the utilization rate of the elements. For a serious lack of some elements, and root damage, or need to apply trace elements, foliar fertilization should be carried out, the concentration of which should be controlled at 0.3% - 0.5%. The fertilization time is in the evening, spraying from the back of the leaves. In order to improve the utilization rate of fertilizer, the plant vigor element can be added to make the plant return to normal as soon as possible. In order to prevent fertilizer damage, it is better to apply thin fertilizer frequently. Under normal circumstances, the rose has more flowers and needs more fertilizer. The base fertilizer should be applied after pruning in winter and before germination. Enough organic fertilizer should be applied, the fertilization range is around the crown diameter, and the depth is 20-30cm. In the growing season, it is necessary to apply fertilizer for many times, during the leaf spreading period, after full bloom and at the beginning of August. The best way to apply fertilizer is available nitrogen, phosphorus and potassium. During leaf spreading, new roots grow in a large amount, and a small amount of fertilizer should be applied instead of concentrated fertilizer, so as to prevent the growth of new roots from being affected. At the end of August, the nitrogen fertilizer should be less, but the phosphorus and potassium fertilizer should be more, so as to prevent the autumn shoots from excessive frost. Top dressing depends on the size and growth of the plant. Generally, it is suitable to use 100-150g per plant at a time.
Reason 4: improper trimming
Pruning is divided into growth season pruning and winter pruning. Pruning in the growth season is to cut off the pedicel and dead branches in time after flowering, and to cut off the rootstock tillers sprouting at the base of the grafted plant. The other is to leave 8 to 12 buds short cut on the current year's flowering branches 20 days after the previous flower withers, then high quality flower branches can be obtained. Pruning in winter is to promote the full return of nutrients in the branches and leaves, which is best carried out 3 to 4 weeks after frost. The general principle of pruning is to cut off the disease and insect branches, fine and weak branches, parallel school, over dense branches and inward branches, to keep straight and oblique branches, weak school and strong pruning, strong tree and strong branch and light pruning.
Rose Pictures
Through the analysis of the above reasons and mastering the above technical points, I believe that we can basically raise a plate of rose flowers with strong branches, leaves and flowers.