There are many who love flowers, and many love roses alone. Xiaobian is also half a flower lover and loves roses. If one morning we find that the leaves of our own rose suddenly turn yellow, we will feel very sad. Today, I'll explain the yellowing of rose leaves. Let's have a look.
Rose rose leaves yellow reason 1, water yellow. The root rot caused by excessive watering is characterized by no obvious change of old leaves and yellowing of young leaves;
Solution: if the lower leaves of the rose have turned yellow, it is necessary to stop watering immediately. Potted roses will loosen the soil or medium around the plant and let the water evaporate as soon as possible. Then cut off the rotten root system and spray low concentration disinfectant. Remember to keep ventilation. Remember to do "see dry see wet", must not blindly water.
2. Dry yellow. Due to water shortage and drought, the old leaves from bottom to top turn yellow first. If the water shortage time is a little longer, the whole plant will be yellow and even die;
Solution: timely watering to meet the physiological growth needs of rose plants. When the temperature is high, it should be irrigated in the morning and in the evening. When the temperature is not high in cloudy days, it can be irrigated all day.
3. Fat yellow. Due to excessive fertilization or high concentration, the young leaves are thick, glossy and uneven;
Solution: fertilizer should pay attention to thin fertilizer, frequent application, avoid too thick. In order to promote dark green and glossy leaves, appropriate ferrous sulfate solution can be added into fertilizer. It can make the color of the leaves darker and the ornamental value higher. When applying topdressing, nitrogen and potassium are the main fertilizers, and the water of rotten cake fertilizer is the best.
4. Lack of fertilizer yellow. It is caused by insufficient fertilizer, low concentration of fertilizer and long interval of fertilization;
Solution: if you don't apply fertilizer in time after seeing this phenomenon, it will also cause the whole plant yellow leaves or even death. For flowers lacking fertilizer, it is forbidden to apply a large amount of concentrated fertilizer at a time, so as to avoid root burning; pay attention to applying more vanadium fertilizer water, or put some rust iron into the soil, or buy the iron tree special fertilizer in the flower market for use, which can make the iron tree leaves dark green and glossy, and improve the ornamental value.
5. Iron deficient yellow leaves. Due to the great changes of soil fertility conditions, the phenomenon of yellow leaves often appears in greenhouse, which is characterized by obvious young leaves, light old leaves, yellow mesophyll and green veins, forming a typical network;
Solution: ferrous sulfate solution can be applied to solve the problem, the method is: cake fertilizer 7 parts, ferrous sulfate 5 parts, water 200 parts with multiple liquid pouring.
6. Pest damage. In recent years, scarab, Scarab and ground tiger have a serious trend in recent years, causing great harm to the leaves and roots of roses. It is one of the main reasons for the yellow leaves of rose.
Solution: reasonable spraying of appropriate concentration of sterilization, insecticidal, foliar fertilizer. It can be sprayed with certain concentration of manganese zinc, polyantimycin, efungetor, chlorothalonil, deltamethrin, cyhalothrin, compound 92o, amino acid aqueous solution, etc. generally, it should be sprayed once every 10 days or so, and fungicide should be sprayed about 3 times. Insecticide and foliar fertilizer should be determined according to the growth of rose plants. Serious cases can be combined with root irrigation.
Soilless culture of rose and rose
The substrate of rose soilless culture is composed of perlite and granite millet in a certain proportion. The particle size of perlite is 1.5-6 mm, that of millet is 0.5-1.5 cm, and the thickness of substrate is 30 cm. When filling the substrate, first fill the bottom of the trough with 15cm of small stone rice, and the upper 15cm is filled with a layer of small stone rice and a layer of perlite. The pH should be controlled at 6-7.
2、 Cultivated varieties
The selected variety is samonsha, a bright red variety introduced from Holland. The characteristics of the original variety of samonsa cultivated in greenhouse without soil can be well preserved. Its branches are long and straight enough, the flowers are large, and the flowers are like cup-shaped, with high yield and good quality, which are very popular with consumers. The planting time is from April to May every year. If the greenhouse is used for soilless planting, flowers can be successively produced and put on the market from October of the current year to May of the following year, and the production will be stopped from June to September. The plant spacing × row spacing was 25 × 30cm, 4 rows per trough, and about 2500 plants could be planted per 0.5 Mu greenhouse.
3、 Measures for summer and winter
In summer, the temperature inside the shed sometimes exceeds 40 ℃. At this time, it is necessary to take measures to reduce temperature, cover the roof with 45% black sunshade net, and spray water in the shed frequently. Generally, it can reduce 5-10 ℃ to make rose grow normally.
Generally, roses can live through the winter in Guangdong, but in order to accelerate its growth and increase its yield, plastic film and white sand net should be sealed around the shed. The temperature in the shed can be increased by 5-10 ℃ in sunny days, 3-5 ℃ in cloudy days, and 1-3 ℃ in rainy days.
4、 Nutrient solution management in soilless cultivation of rose
1. Nutrition of rose
According to the analysis: the leaves contain 3.0% nitrogen, 0.2% phosphorus, 1.8% potassium, 1.0% calcium and 0.25% magnesium. In order to meet the nutritional requirements of roses, the contents of main elements in the nutrient solution must reach 170ppm of nitrogen, 34ppm of phosphorus, 150ppm of potassium, 120ppm of calcium and 12ppm of magnesium.
2. Nutrition liquid formula of rose
There are many formulas for Rose nutrient solution. Through the comparison of ten kinds of formulas, the formula prepared by our institute and by ourselves is better. The formula contains n253ppm, P 51ppm, k278ppm, CA 162ppm and Mg 34ppm. The pH of the formula is 5.5-6.5, and the total concentration is 0.23%. This formula is more stable, generally do not need to adjust pH.
3. Construction of nutrient solution tank
In order to avoid sedimentation caused by mutual reaction between nutrient solutions, two nutrient solution pools must be built, one containing calcium nitrate and the other containing other large and trace elements. The nutrient solution pool is built outside the shed, 2 meters above the high ground, and two pools each are calculated according to the requirement of 0.5 Mu greenhouse to hold 2 cubic meters of water. The volume of the two tanks is the same, so should the volume of nutrient solution. When fertilizing, the two water systems were opened at the same time.
4. Application of nutrient solution
In the early stage of planting, the amount of irrigation can be less, and the formula can be applied once every other day or two days. After entering the production period, the full amount of formula, the liquid supply is gradually increased, the liquid can be drenched once a day in sunny weather, and once in two or three days in cloudy or rainy days.
5、 Water management
In summer, water should be sprayed once every hour on sunny days. The amount of water sprayed should not be too much. If the leaf surface is wet, too much will dilute the nutrient solution of the seedbed. In winter, if the temperature in the shed is above 30 ℃, spray water once at noon.
6、 Pruning technique of rose
1. After transplanting, buds should be removed in time to enrich the branches. The buds formed in midsummer should also be removed and concentrated nutrients should be concentrated to cultivate tree vigor.
2. Samonsha grows three buds on the shoot. In the flowering season, he has to remove the secondary buds on both sides every morning.
3. Pruning strip should be cut off too long, cross, overlap, dead, disease and insect pests, thin and weak branches, and sprouts on the rootstock should be removed in time.
4. To control the flowering period, the annual "Valentine's Day" (February 14) is the golden season for Rose sales. Therefore, it is necessary to control the opening of roses during the "Valentine's Day". The roses planted in the open field in Guangdong Province will bloom about 65 to 75 days, and it will be 10-20 days earlier in soilless cultivation in greenhouse than that in open field. Therefore, it is necessary to cut branches and leave buds for roses planted in soilless greenhouse from December 5 to 15.
5. The seedlings planted from April to may can produce flowers in December. In the second year, the yield is about 50000 branches per mu, and in the third year, the yield is more than 100000 stems per mu. Cut flowers should be harvested when the green calyx has opened and the outer petals are loose. The cutting position of cut flowers mainly depends on the strength of the branches. If the branches are strong, 3-4 buds can be left. If the flower branch is short or the leaves on the branch are less, it can be cut in the middle or upper part of the flower branch to make the flower bud grow on the upper part
2. Pay attention to keep warm when buying flowers, especially in the cold winter season. If you don't pay attention to the flowers and plants, they will be frostbitten by the cold wind in the process of transportation, and the leaves will become dry and fall in the later maintenance.
3. Many people have the habit of changing pots and soil immediately after buying new flowers. In fact, this habit is very bad. The newly bought potted flowers need a certain period of time to adapt to the new growth environment because of the changes in the environment. At this point, if you change the pot and soil immediately, it will make the flowers and plants uncomfortable and stop growing. The correct way is, if the newly bought potted flower soil pot is suitable, you don't need to change the pot for soil. If you are worried that the new flowers will bring back insect pests, you can first disinfect them with insecticides and fungicides, isolate the new flowers from the existing flowers and plants at home, and then place them together with other flowers and plants after observing their normal growth for a period of time.
4. Because commercial potted flowers grow in flower sheds and flower markets, the temperature and humidity there are more suitable for its growth needs. Therefore, the newly bought potted flowers should try their best to create a suitable growth environment for them, arrange their placement according to their light preference, and determine the management of fertilizer and water according to their growth habits. It should be noted that the newly purchased potted flowers need a period of adaptation and recovery period due to the change of environment, so it is not suitable to apply fertilizer immediately, and then apply a certain amount of organic fertilizer after the adaptation period.