What if there are spots on African claw leaves? There are yellow leaves.

What about spots on African claw leaves? Yellow leaves turn yellow for many reasons:

(1), long-term fertilization. Long-term lack of nutrients such as nitrogen fertilizer leads to sparse branches and leaves, thinning and yellowing of leaves. It is necessary to replace new cultivation water in time and gradually apply dilute decomposed liquid fertilizer or compound flower fertilizer. ..

(2) excessive fertilization. Excessive fertilization will result in uneven thickness of new leaves and brown loss of old leaves. Stop fertilization immediately, increase the amount of water exchanged, so that fertilizer will be lost, or immediately pour the pot. ..

(3), hot and high temperature. If daffodils are placed under high temperature and strong light, it is easy to cause the tips and edges of young leaves to burn or the leaves to fall off. Need to be moved to a ventilated and cool place in time. ..

(4) excessive shading. If plants are kept in a cool place or in a place with insufficient light for a long time, the branches and leaves will turn yellow. ..

(5) Soil and water are alkaline. Due to the lack of soluble iron and other elements that can be absorbed by water, leaves will gradually turn yellow. Acidic soil and water should be used when planting, and alum fertilizer should be poured frequently during the growing period. ..

(6), airtight. Excessive application of nitrogen fertilizer, lush growth of branches and leaves, long-term non-pruning, insufficient illumination of branches and leaves in the inner room, easy to cause leaves to yellow and fall off. Fertilization should be reasonable, and pruning should be strengthened to make it ventilated and transparent. ..

(7), air drying. When the indoor air is excessively dry, dry tips or scorched edges often appear. Attention should be paid to increasing air humidity by spraying water and covering plastic film. ..

(8) Improper temperature. When the room temperature is too low in winter, plants are damaged by cold, which leads to yellowing of leaves, and in severe cases, yellowing dies. If the room temperature is too high, the transpiration of plants will be too strong, the water and nutrients in roots will be in short supply, and the leaves will turn yellow. Please pay attention to adjust the room temperature in time.

(9), pests and diseases. Leaf spot caused by fungi and other pathogens is easy to cause local necrosis of leaves and yellow spots or patches appear. In severe cases, the leaves are all yellow and fall off, and should be sprayed in time to prevent and control them. ..

(10), strong * *. Too high concentration of pesticides used in pest control, or toxic gas pollution in the atmosphere, or sudden pouring of cold water when the temperature is high, are easy to cause local yellowing, burning and even death of the whole plant. Therefore, we should pay attention to the rational use of pesticides and try to eliminate air pollution sources. Avoid watering flowers with cold water around noon in midsummer. Finally, the yellow leaves of potted flowers are sometimes caused by one reason, but often by many factors. We should make a correct diagnosis before we can prescribe the right medicine. ..

What is the cause of the rust spots on the dragon's paw leaves? Is it because dirty water falls on the leaves when it is wet or watered? My African claw (aloe) has been placed on the balcony, which can bask in the sun for half a year. Try to water the leaves without touching them. If there is, rinse it with clear water immediately, and it will be fine. Just follow my sample variety.

What should I do if the African claw leaves are dry? Can African claw leaves be eaten raw? Dragon claw leaf, the scientific name of pistil wood (scientific name: Tupidanthus calyptratus hook. F.&; Thomas. ),

Also known as: Liriodendron, Dandelion, Liriodendron grandiflora, etc. , belonging to Umbelliferae and Araliaceae. Nature and taste: sweet, bitter and warm. Produce China.

, Myanmar, India, Vietnam, Bangladesh. It has the effects of promoting qi circulation, relieving pain, promoting blood circulation, relieving swelling and strengthening bones and muscles.

What if there are spots on Milan's leaves? First of all, you have to verify what color the plaque is, whether it is rust, black, brown or yellow.

If it rusts, it is most likely to be sprayed with ferrous sulfate solution. Even the new leaves will have a small amount of rust spots, which is normal.

If it is dark brown plaque, it needs to be sprayed with bactericide.

If it's macula, it's mostly biological diseases, so it's necessary not only to spray fungicides to prevent and control it, but also to improve the conservation environment and management methods.

Although Milan does not require high air humidity, frequent water spraying can make the leaves clean and bright, remove dust and reduce the occurrence of diseases. Note that it is best to spray water in the morning, and try not to spray it when the temperature is lower than 15℃ in winter to prevent freezing injury.

What if there are spots on Babu's leaves? Brazilian wood likes sunny, high temperature and high humidity environment, and is also resistant to shade and dryness. It also grows well in bright scattered light and dry environment in the northern bedroom.

As long as the temperature and other conditions are suitable, Brazilian wood can grow all year round. Proper shading is needed when it is hot in summer, and the room temperature should not be lower than 5℃ in winter. But it is best to hibernate in winter, and the hibernation temperature is 65438 03℃. If the temperature is too low, chloasma will appear on the tips and edges of leaves. Basswood should be placed in a well-lit place indoors. If the light money is too weak, the markings on the leaves will turn green and the basal leaves will turn yellow, losing their ornamental value. During cultivation, the water quality should be kept clean, and it should be watered 1 ~ 2 times a week, so as to prevent the trunk from rotting. When it is hot in summer, you can improve the air humidity by spraying, and spray water on the leaves to keep it moist. During the growth period, the Brazilian wood should be properly topdressed outside the roots, and the leaves should be diluted 100 times, once every two months. After several years of cultivation, if the plant is too high or the leaves at the lower part of the stem fall off and the plant shape is poor, it should be pruned. Change pots or soil in early spring every year. Potted Brazilian wood, if the environment is not suitable, will have red spiders, thrips, scale insects and other hazards. In addition, excessive ventilation, drought, irregular watering and excessive fertilization will all lead to the tip burning.

Clivia has yellow leaves and long spots. Send a picture. Clivia likes to scatter light and put it in a bright place indoors. It doesn't matter if the soil is dry without watering. It is afraid of waterlogging, and watering is easy to rot its roots. It is best to control watering. Leaves are often sprayed with potassium dihydrogen phosphate, which makes them greener.

What should I do if there are spots on the rhododendron leaves? Rhododendron is prone to brown spot disease, which can cause early defoliation, thus reducing its ornamental value.

First of all, symptoms

It mainly harms leaves, and the old leaves at the lower part of the plant are the first to get sick. In the early stage of the disease, the reddish-brown spots on the leaves are 2~5 mm in diameter, and in the later stage of the disease, the centers of the spots become grayish brown and grayish white, and the edges are dark brown. Black or grayish brown spots and mildew filaments appear on the surface of the lesion. Pathogen: Cercospora rhododendron, a subspecies of Hemiptera. The pathogen overwinters in diseased leaves and branches in the form of mycelium, and spreads spores through wind and rain when the temperature rises in the next spring.

Second, the characteristics of the disease

Rhododendron cultivated in the open field usually begins to get sick in April-May, and the disease does not stop spreading until June 5438+February. Azaleas in greenhouses can get sick all year round. High temperature, humid and rainy environment can easily lead to the occurrence and prevalence of diseases. Generally, the earlier the rainy season, when it is rainy, foggy and dew is heavy, diseases may occur.

Third, prevention and control methods

1. Select varieties with strong disease resistance for cultivation. Such as the South Pole and Five Treasures.

2. Strengthen cultivation management: thoroughly remove diseased leaves on plants and fallen leaves and dead branches on the ground in winter and early spring (also during the growth period).

Combine pruning to remove diseased branches. The row spacing between plants (pots) should not be too close during cultivation. Daily watering time should not be too late, and root watering should be adopted. Pay attention to ventilation and light transmission, and control humidity. Appropriate application of ferrous sulfate, more fully decomposed organic fertilizers such as bean cake, hoof nail and fishy smell, and reasonable ratio of nitrogen, phosphorus and potassium fertilizer.

3. Chemical control: When the plants are spreading leaves, spray Bordeaux solution once every half month for 3-4 times continuously. Spraying 70% 1000 times of Jiatuo or 500-800 times of carbendazim wettable powder or 32% 1000 times of gramineous plants before and after azalea flowering, once a week, 2-3 times in a row.

How is the leaf of Stevia rebaudiana turning yellow? Due to leaf blight, the yellow leaves of Stevia rebaudiana still have spots.

Prevention and control methods:

(1) Rotation and stubble replacement: Carefully select the seedbed, reduce the spread of bacteria with the soil, and try to choose disease-free cuttings. Non-continuous cropping fields should be selected for field planting, and paddy-upland rotation should be implemented if conditions permit.

⑵ Strengthen field management: dig deep into the soil, open three ditches in the field, mainly irrigate around the rhizosphere without flooding, ventilate in time to reduce humidity and clean up the sick and disabled.

⑶ Chemical control: Apply pesticide as early as possible when the climate is suitable, and continue to use it after sporadic disease in the field. Difenoconazole, flusilazole, thiophanate-methyl, chlorothalonil and other drugs can be selected alternately. Some stevia varieties are sensitive to mancozeb and thiophanate-methyl. , should be tested in a small range before use.