Magnolia Propagation and Cultivation Methods and Pest and Disease Control Techniques

I. Morphological characteristics: A deciduous tree, about 25m tall. Leaves alternate, relatively large, broadly obovate to obovate, entire. Flowers solitary at the top of branches, white bell-shaped, fragrant. The flowering period varies by region, such as Kunming from November to December, Guangzhou from February to March, Hangzhou in March. Cultivated varieties are short with dense branches, and flowers are large and abundant. Seedling plants are tall with straight trunks, branches slightly sparse, flowers sparse and foliage luxuriant, but with strong adaptability and rapid growth. Propagated by sowing, grafting, layering and cuttings.

Growth habits: Warm and humid, with a shaded side environment, slightly shade-tolerant, mature trees prefer light, suitable for growing in acidic or slightly alkaline soil rich in humus and with good drainage. Prefers fertilizer. Fleshy roots, intolerant of waterlogging, also intolerant of drought. Magnolia is sensitive to temperature; magnolia can withstand brief low temperatures of -20°C.

Garden use: Magnolia is a famous early spring flowering tree species, blooming before leaves emerge. Flowers are large and fragrant, with thousands of buds on branches, flowers bright but not gaudy, elegant but not fawning, pure and beautifully clear, like a jade tree. In classical gardens, it is often planted in front of halls and behind courtyards, and named Wulan Hall or Magnolia Garden. If planted one or two along roadsides, lawns, in front of and behind pavilions, inside and outside lattice windows, or beside moon gates, it is full of charm. Magnolia paired with pine trees, with a few rocks placed below, feels even more anciently charming and naturally formed.

Propagation and cultivation: Seeds are mainly used to cultivate rootstock. For grafting, Magnolia liliiflora (purple magnolia) and Magnolia amoena (Huangshan magnolia) are used as rootstock, using cleft grafting, side grafting or bud grafting. Cuttings can be done in early June when the lateral buds of new shoots are plump. Layering is suitable for preserving and developing famous and superior varieties. For seedlings from sowing or grafting, apply heavy base fertilizer, control density, and sparse flower buds can be seen in 3 to 5 years. After 2 to 3 years of planting, they enter the full flowering period. Before planting, heavy base fertilizer should be applied, and planting should be appropriately deep. Summer is the season for magnolia growth and bud formation; irrigation should be done during drought. Pruning can maintain the beautiful tree posture of Wulan, ventilation and light transmission, promote flower bud differentiation and make next year's flowers large and colorful. Magnolia diseases include black spot disease, anthracnose, etc. Pests include large bagworm moths, eri silkworms, sphinx moths, etc.

II. Pest and Disease Control

1. Anthracnose control methods

(1) Strengthen water and fertilizer management, increase application of organic fertilizer, and enhance plant disease resistance.

(2) Promptly prune diseased leaves on trees, sweep up diseased and withered fallen leaves on the ground, and bury them deeply in a centralized manner to reduce sources of infection.

(3) In the early stage of the disease, spray 84.1% Haoduobao wettable powder and 77% Keshade wettable powder or 1:2:200 Bordeaux mixture, etc., once every 15 days, for a total of 2 to 3 sprays. Afterwards, depending on the condition, selectively spray 75% chlorothalonil wettable powder 600 to 1000 times solution and 70% anthracnose fumate 500 solution and 65% zineb wettable powder 500 to 800 times solution, 50% carbendazim wettable powder + 75% chlorothalonil wettable powder 800 times solution, 50% mixed sulfur suspension concentrate 500 times solution, 70% thiophanate-methyl ultra-micro wettable powder 1500 times solution, etc.

2. Black spot disease control methods:

(1) Strengthen nursery management, enhance tree vigor, and improve disease resistance. Select loose, fertile, well-drained soil, apply fully decomposed cake fertilizer, loosen soil and water promptly, and pay attention to preventing frost damage in the north.

(2) Promptly remove fallen leaves on the ground, prune severely diseased leaves on trees, and bury them deeply in a centralized manner.

(3) In the early stage of the disease, spray 1:1:160 Bordeaux mixture or 0.3 to 0.5Be lime sulfur mixture, 77% Keshade wettable powder, 30% copper hydroxide suspension concentrate, 25% copper ammonia complex water solution, 50% tuzet wettable powder 600 to 800 times solution, 75% chlorothalonil wettable powder 800 times solution, 70% thiophanate-methyl wettable powder 1000 times solution, etc., once every 10 to 15 days, for 2 to 3 consecutive sprays.

3. Yellow stinging moth control methods:

(1) In summer (1-generation areas) and winter-spring (1 to 2-generation areas), in combination with pruning and other field operations, cut off or break off cocoons.

(2) When young larvae are clustered and causing damage, prune off infested leaves and kill the larvae.

(3) During the young larval stage, spray 20% dimilin suspension concentrate, 20% diflubenzuron No. 3 suspension concentrate, or throughout the larval stage spray Bt emulsion, Bacillus thuringiensis, etc.

(4) When necessary, during the larval stage, spray insecticides such as fenpropathrin, phoxim, fenitrothion, etc.