What are the prevention and control methods of stem rot of tortoise shell holly?

Tortoise shell holly is mainly distributed in the lower reaches of the Yangtze River to South China, East China and North China, and its producing areas are mainly concentrated in Hunan, Zhejiang, Fujian and Jiangsu. It likes warm, humid and sunny environment and can be watched. Stem rot is one of the main diseases of tortoise shell holly, so what are the control methods of tortoise shell holly stem rot?

I. symptoms of stem rot of tortoise shell holly

At the beginning of the disease, irregular edema spots appeared near the ground at the base of the stem, light brown, the cortex of the diseased part became soft, water stains, easy to peel off, there was a peculiar smell, and the diseased part gradually expanded around the base of the whole stem, and the color became darker. In the later stage, there were white particles on the diseased part, which affected the upward transport of water and nutrients, resulting in wilting of the branches. With the severity of the disease, the branches above the affected parts gradually withered and died.

2. control methods of stem rot of tortoise shell holly

1. Gentle slopes with good ventilation and drainage should be selected for planting. Strengthen cultivation management, cut off diseased and dense branches, use hedgerows and scaffolding to increase ventilation and transparency in the garden, pull out seriously diseased plants in time, and disinfect the soil with quicklime.

2. Songda bio-organic fertilizer was used to improve the soil, and the overwintering seedlings were removed from the soil to show their roots slightly after the temperature was stable for 12 ℃.

3. Chemical control in the early stage of the disease: scrape off the disease spot at the base of the stem with a knife, and then smear the base of the stem with Guoguang Songer 600 times solution. At the same time, the roots were irrigated with 2000-fold solution of Guoguang Genbao and 1500-fold solution of Guoguang Chongzhoubao, each plant was irrigated with 500ml solution for 1-2 times according to the situation.

III. Matters needing attention in the maintenance of tortoise shell holly

1. Soil

Tortoise shell holly is a highly adaptable tree species, no matter sunny or shady can have children, like moist and fertile slightly acidic loess, neutral soil can also.

2. Reproduction

The tortoise shell holly used to make bonsai is usually propagated by cuttings, which is generally carried out in the growing season from May to July. Cuttings can choose first-year or current-year strong and substantial branches, remove the lower leaves, and put them in bright light and no direct sunlight for maintenance, keep the soil and air moist, and take root in about 50 days.

3. Watering

Like warm, humid and sunny environment, resistant to semi-shade, keep the basin soil moist during the growing period without stagnant water, and pay attention to spraying water to the plant when the air is dry to make the leaf color moist. Apply thin alum fertilizer and water every 12-20 days to provide sufficient nutrients, make the leaves green and bright, and make the plants full of vitality.

4. Pick the heart

Because the germination of tortoise shell holly is very strong, it is necessary to pick the heart in time and remove those superfluous new buds in order to maintain the beauty of the tree.

5. Overwintering

It is required to be cold in winter, and the temperature above 0 ℃ can be maintained in the cold room, and the basin soil can not be frozen. The area south of the Yellow River can also overwinter in the outdoor shelter from the wind and the sun, pour water once before overwintering, and replenish water in time to avoid the basin soil from being too dry to prevent dry freezing, but it is also necessary to prevent the soil from accumulating water, otherwise it will cause rotten roots.