Causes and countermeasures of leaf yellowing of Sabina vulgaris

Sand cypress can be used for evergreen ground cover or basic planting in gardens to increase greening levels. It is also a good ground cover plant for slope protection. However, if it is not properly managed, yellow leaves will appear. The main reasons are as follows:

soil drying

Although Sabina vulgaris is suitable for dry sand growth, if it is in the dry soil and air environment for a long time, it is easy to appear white and yellow leaves at the lower part of the branches. If it is not grafted seedlings, especially those without Platycladus orientalis as rootstock, this situation is more likely to occur.

prevention measures

Water should be poured until thoroughly watered. At the same time, sand cypress requires a loose, transparent ecological environment, if the soil is in a long-term over-wet state, the plant will cause root rot due to hypoxia, yellow leaves, especially the new leaves yellow. Therefore, the amount of watering should be controlled and the soil should be properly loosened and ventilated. Sometimes too much fertilizer can also cause yellow leaves, should control the amount of fertilizer.

diseases

Mycelia of Cypress rust overwinters on cypress trees. Winter spores mature from February to March of the next year. The gall swells and dehisces. Under suitable conditions, a large number of basidiospores are produced and begin to infect the host plants. The host plants include Begonia, Hawthorn, Pear and Apple. Aeciospores are produced in early May, the peak period of disease is June, and the spores mature from August to September, and spread to conifers such as sand cypress by wind. The disease mainly damages needles and tender shoots of Sabina vulgaris. At the beginning of the disease, orange yellow, shiny small lesions appeared on the leaves, and then gradually expanded. There were yellow spots the size of needles on the lesions. When the weather was wet, mucus was secreted on them. After drying, the yellow spots turned black, which was the sexual sporangium of pathogenic bacteria. In the coming year, it will germinate in rain and produce basidiospores, which will be transmitted by wind and rain. In warm and rainy spring years, the disease is severe. If there are sporadic yellow spots on the twigs and leaves, it is generally the disease.

prevention measures

Cut off diseased branches in winter. Spraying a mixture of 0.3% sodium pentachlorophenol and 1 baume on sand cypress from October to November can prevent rust spore infection. Before teliospore germination, spraying 1 wave to 2 Baume degrees of sulfur mixture or 160 wave to 200 Baume degrees of Bordeaux mixture 2 to 3 times every 7 to 10 days in the middle and late March had better effect.

pest

If the sand cypress appears yellow in small areas, it may be damaged by borer pests (such as longicorn) after eliminating diseases. Carefully check the branches to see if there are defecation holes or broken withered branches to see if there are longicorn harm insect channels.

prevention measures

Strengthen the conservation and management of Sabina vulgaris, enhance tree vigor and reduce the opportunity of pest invasion. Inject 30 to 50 times 80% dichlorvos emulsifiable concentrate into the bore holes of Sabina mongolica branches with an injector to kill larvae. Before injection, remove sawdust and insect faeces from the insect passage, and seal the insect passage with clay after injection. If the pest is serious, it can be removed and burned intensively.

physiological chlorosis

If there is a large area of yellowing phenomenon in the tiled sand cypress, no diseases and insect pests are found, and the soil is moderately dry and wet, it may be physiological yellowing disease of sand cypress. The leaves of chlorosis were yellow in the early stage, then yellow and white, especially the new leaves. Severe leaf tissue necrosis, affecting normal photosynthesis, and then the whole plant slowly died. Usually, there are more alkali salts in soil and water in northern areas, which affect the absorption of iron ions by plants and cause iron deficiency in plant physiology, resulting in yellowing disease.

prevention measures

Ferrous sulfate can be mixed into fertilizer for application. Ferrous sulfate 2.5 kg to 3 kg, oil meal 5 kg to 7.5 kg, dung 10 kg to 15 kg, water 200 kg to 250 kg mixed, decomposed into black can be used; spraying 0.2‰ ferrous sulfate solution, the leaves are sprayed on the front and back, once every 3 days, for several times, can improve the phenomenon of young leaves yellowing.

The cause of yellow leaves of Sabina mongolica is sometimes single, sometimes caused by the combined influence of two or more reasons, which requires careful analysis, careful diagnosis and appropriate medicine.

Causes and Countermeasures of Yellowing Leaves of Sabina mongolica

Yellowing of leaves caused by longicorn beetle

China Garden Network April 10 news: Sandy cypress in the garden can be used for evergreen ground cover or basic planting, increase the level of greening, but also a good slope protection ground cover plants, but if improper management will appear yellow leaf phenomenon, the main reasons are as follows:

soil drying

Although Sabina vulgaris is suitable for dry sand growth, if it is in the dry soil and air environment for a long time, it is easy to appear white and yellow leaves at the lower part of the branches. If it is not grafted seedlings, especially those without Platycladus orientalis as rootstock, this situation is more likely to occur.

prevention measures

Water should be poured until thoroughly watered. At the same time, sand cypress requires a loose, transparent ecological environment, if the soil is in a long-term over-wet state, the plant will cause root rot due to hypoxia, yellow leaves, especially the new leaves yellow. Therefore, the amount of watering should be controlled and the soil should be properly loosened and ventilated. Sometimes too much fertilizer can also cause yellow leaves, should control the amount of fertilizer.

diseases

Mycelia of Cypress rust overwinters on cypress trees. Winter spores mature from February to March of the next year. The gall swells and dehisces. Under suitable conditions, a large number of basidiospores are produced and begin to infect the host plants. The host plants include Begonia, Hawthorn, Pear and Apple. Aeciospores are produced in early May, the peak period of disease is June, and the spores mature from August to September, and spread to conifers such as Sabina vulgaris by wind. The disease mainly damages needles and tender shoots of Sabina vulgaris. At the beginning of the disease, orange yellow, shiny small lesions appeared on the leaves, and then gradually expanded. There were yellow spots the size of needles on the lesions. When the weather was wet, mucus was secreted on them. After drying, the yellow spots turned black, which was the sexual sporangium of pathogenic bacteria. In the coming year, it will germinate in rain and produce basidiospores, which will be transmitted by wind and rain. In warm and rainy spring years, the disease is severe. If there are sporadic yellow spots on the twigs and leaves, it is generally the disease.

prevention measures

Cut off diseased branches in winter. Spraying a mixture of 0.3% sodium pentachlorophenol and 1 baume on sand cypress from October to November can prevent rust spore infection. Before teliospore germination, spraying 1 wave to 2 Baume degrees of sulfur mixture or 160 wave to 200 Baume degrees of Bordeaux mixture 2 to 3 times every 7 to 10 days in the middle and late March had better effect.

pest

If the sand cypress appears yellow in small areas, it may be damaged by borer pests (such as longicorn) after eliminating diseases. Carefully check the branches to see if there are defecation holes or broken withered branches to see if there are longicorn harm insect channels.

prevention measures

Strengthen the conservation and management of Sabina vulgaris, enhance tree vigor and reduce the opportunity of pest invasion. Inject 30 to 50 times 80% dichlorvos emulsifiable concentrate into the bore holes of Sabina mongolica branches with an injector to kill larvae. Before injection, remove sawdust and insect faeces from the insect passage, and seal the insect passage with clay after injection. If the pest is serious, it can be removed and burned intensively.

physiological chlorosis

If there is a large area of yellowing phenomenon in the tiled sand cypress, no diseases and insect pests are found, and the soil is moderately dry and wet, it may be physiological yellowing disease of sand cypress. The leaves of chlorosis were yellow in the early stage, then yellow and white, especially the new leaves. Severe leaf tissue necrosis, affecting normal photosynthesis, and then the whole plant slowly died. Usually, there are more alkali salts in soil and water in northern areas, which affect the absorption of iron ions by plants and cause iron deficiency in plant physiology, resulting in yellowing disease.

prevention measures

Ferrous sulfate can be mixed into fertilizer for application. Ferrous sulfate 2.5 kg to 3 kg, oil meal 5 kg to 7.5 kg, dung 10 kg to 15 kg, water 200 kg to 250 kg mixed, decomposed into black can be used; spraying 0.2‰ ferrous sulfate solution, the leaves are sprayed on the front and back, once every 3 days, for several times, can improve the phenomenon of young leaves yellowing.

The cause of yellow leaves of Sabina mongolica is sometimes single, sometimes caused by the combined influence of two or more reasons, which requires careful analysis, careful diagnosis and appropriate medicine.