full house

full house

This entry is compiled and applied by "popular science China" Science Encyclopedia

to examine

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It's a red house. It's called crape myrtle,

Myrtle is a deciduous shrub or small tree of myrtle family, which has a long history of cultivation in China. It is an important landscape tree species. Lagerstroemia indica has beautiful flower posture, gorgeous color and long flowering period. It continues to open from June to September, so it has the reputation of "hundred day red" and is deeply loved by people.

Plant characteristics

Deciduous shrubs or small trees, up to 7 meters high; bark smooth, gray or grayish brown; twigs twisted, twigs slender, with 4 edges, slightly winged. Leaves alternate or sometimes opposite, papery, elliptic, broadly oblong or obovate, 2.5-7 cm long and 1.5-4 cm wide, apically mucronate or obtuse, sometimes slightly concave, base broadly cuneate or suborbicular, glabrous or puberulent along midvein below, lateral veins 3-7 pairs, veinlets inconspicuous; sessile or petiole very short.

Flowers pale red or purple, white, 3-4 cm in diameter, often forming a terminal panicle of 7-20 cm; pedicel 3-15 mm long, both rachis and pedicel pilose; calyx 7-10 mm long, smooth outside without edge, but calyx tube with short protuberances, both sides glabrous, lobes 6, trigonal, erect, without appendages; petals 6, shrunk, 12-20 mm long, clawed; stamens 36-42, Outer 6 on calyx, much longer than others; ovary 3-6-locular, glabrous. Capsule ellipsoid or broadly elliptic, 1-1.3 cm long, green to yellow when young, purple black when mature or dry, locular dorsal dehiscence; seeds winged, about 8 mm long. The flowering period is from June to September and the fruiting period is from September to December.

Growth environment

It is a subtropical positive tree species, like light, warm and humid, like fertilizer, drought resistance, strong cold resistance, strong tillering, slightly resistant to shade. The requirements for soil are not strict. It grows strong in fertile, deep, loose and slightly acidic soil. It should not be planted in high groundwater level or wet environment. It has strong resistance to harmful gases and strong dust absorption capacity.

Distribution range

Guangdong, Guangxi, Hunan, Fujian, Jiangxi, Zhejiang, Jiangsu, Hubei, Henan, Hebei, Shandong, Anhui, Shaanxi, Sichuan, Yunnan, Guizhou and Jilin are all grown or cultivated in China.

Mode of reproduction

Sowing and propagation

The seeds are harvested from November to December every year, and are drilled or sown on sandy loam in March next year. The soil was disinfected with chlorothalonil 800 times solution or potassium permanganate 800 times solution before sowing. 50% phoxim granules were evenly sprayed on the bed surface to kill underground pests. The seeds were soaked in 50 ℃ warm water for 2-4 hours. The drill spacing is 30cm and the depth is 2cm. After covering soil, cover grass firmly. When sowing, mix the seeds and fine sand in the ratio of 1:3, sprinkle them on the seedbed evenly, cover with soil about 0.5cm thick, and then cover with grass. In order to keep the soil loose and moist, water should be sprayed once a day in the morning and evening after sowing. Those who grow healthily can blossom in the same year, but they should be cut off in time because of the influence on the future growth.

cuttage propagation

Cutting propagation method is an important asexual propagation method, which can effectively maintain the growth characteristics and ornamental characteristics of Lagerstroemia indica.

1. Hardwood cutting

Before sprouting in spring, 1-year-old strong branches were collected and cut into cuttings of about 15 cm, and the lower end was cut into horseshoe section. The cuttings were disinfected with potassium permanganate, soaked with 0.5g ／ l plant hormone combination (80% IBA + 20% NAA) for 30 seconds, and then inserted into the loose and well drained sandy loam seedbed to expose a bud on the top of the cuttings. After inserting, it is poured with water and covered with plastic film to keep warm and moisture. When the seedlings grow to 15 ~ 20cm, the film can be removed, covered with shading net and watered timely.

2. Softwood cutting

It can be carried out from July to August. The semi lignified branches were cut into 8-10cm long cuttings with 2-3 leaves at the top. The disinfection and rooting agent treatment of cuttings were the same as that of hardwood cuttings. The cutting depth was 3 ~ 4cm. After the cutting, the water was irrigated and the shed was built for shading. Generally 20 days or so can root, and then remove the film, retain the shading net, and timely watering.

Air Layering propagation

It can be carried out in all growing seasons, especially in spring from March to April. For air layering, 1-2-year-old branches can be selected. Cut and girdle the bark about 1.5cm wide with a sharp knife to expose the xylem. Apply the rooting powder solution (diluted according to the instructions) about 3cm above the cut part. After drying, cover the cut part with a cylindrical plastic bag, bind the lower part, fill it with loose garden soil, and fasten the upper part after watering. Check after 1 month, if the soil is too dry, it can be hydrated, cut off and replant after rooting.

division propagation

Before sprouting in spring or autumn, the tillering seedlings germinated in the rhizosphere of the plant were dug out with roots, and the roots and branches were appropriately pruned and planted separately. Small seedlings can bare roots, big seedlings should take mud ball, tending to often prune, shaping, maintain a beautiful tree shape, promote flowering.

Propagation by grafting

From the last ten days of February to the first ten days of March, it was carried out before the sprouting of full bloom branches. When grafting, the stout seedlings were selected as rootstock, and the branches with the required color were used as scions. First, cut a knife at the top of the rootstock, 3 ~ 4cm deep, then cut the scion with 2 ~ 3 buds, 5 ~ 8cm long, into a wedge, and insert it into the split of the Rootstock to align with the cambium. Then the whole grafting position and scion were wrapped up with plastic film, only the bud head was exposed. In this way, the branches with different colors are grafted on the same rootstock layer by layer to form a tree with multiple colors. After 2-3 months of grafting, the membrane can be loosened. At this time, the ear length can reach 50-80cm. The branches should be cut short in time to avoid wind breaking, and can be cultivated into strong branches.

cultivation techniques

Water and fertilizer management

Mantanghong is a positive tree species. It should be planted in a sunny environment and a moist and fertile loam with good drainage. In spring, the soil was watered once or twice before germination to keep the soil moist during the growing period. The vitality of Lagerstroemia indica and the ability to resist harmful infringement are strong, so the management of Lagerstroemia indica is extensive. The flower bud of Lagerstroemia indica was formed in the same year. In order to make Lagerstroemia indica bloom in the same year, we should apply rotten organic fertilizer and increase the application of phosphorus and potassium fertilizer in early spring to facilitate the formation and differentiation of flower bud. From May to June, topdressing with a small amount of nitrogen fertilizer was beneficial to flower propagation, color and flowering time.

trim

The flower bud of Lagerstroemia indica grows at the top of the new branch of the current year. When pruning, the 1-year-old branch should be cut back again. Generally, the whole branch length is about 5 cm to promote the spring flowering. Avoid cutting new branches sprouting in spring, otherwise it is easy to cause the phenomenon of only long branches without flowering. In order to prolong the flowering period, the residual flowers that have been opened can be timely cut off during the growth period, so as to prevent the seeds from setting and promote the next round of flower branch growth. In order to make the trunk strong, a large number of flower branches can be cut and the trunk can be cultivated with concentrated nutrition.

Pest control

In order to promote the growth of Lagerstroemia indica and improve its disease resistance, we should take comprehensive control measures and pay attention to the management of fertilizer and water. Reasonable fertilization, pay attention to the combined application of nitrogen, phosphorus, potassium and other elements of fertilizer, avoid partial application of nitrogen fertilizer. Reasonable irrigation, early watering in drought, timely drainage in flood, reasonable pruning, in order to facilitate ventilation and light transmission, timely and thoroughly clean up the residual branches and diseased leaves, centralized burning, and eradicate the source of disease.

powdery mildew

The disease is a kind of fungal disease, which mainly damages the leaves. The young branches and leaves are more easily infected than the old branches and leaves. In the early stage of the disease, small white powdery spots appeared on the leaves, covered with a layer of white powdery mildew layer, and in the later stage, the white powdery mildew layer became gray. Control methods: spraying 80% mancozeb WP 500 times or 50% carbendazim WP 800 times at the early stage of the disease.

Coal pollution

The pathogen of the disease belongs to fungi. There are many kinds of pathogens, which can infect many kinds of pathogens at the same time. 50% carbendazim WP 600 times or 70% thiophanate methyl 500 times were used for control. For Lagerstroemia indica which had serious disease in the past year, 200-300 times of sodium terpineate could be sprayed before germination in spring to eliminate the overwintering disease source. Because the secretion of aphids, scale insects, whiteflies and other insects is the basis of the existence of coal pollution pathogens, it is very important to timely control aphids, scale insects and other pests.

Cercospora leaf spot

The pathogen of the disease is fungi, which mainly damages the leaves. The disease usually starts from the old leaves in the lower part, and then gradually spreads to the new leaves in the upper part. The disease likes high temperature and high humidity, and the lesions are purple black to black, round or nearly round in size. 65% mancozeb WP 1000 times or 75% chlorothalonil WP 800 times were used to control the disease.

Insect pest

During the growing period of mantanghong, it is easy to be damaged by aphids, scale insects, Spodoptera litura, Spodoptera litura and sawfly. The main damage to leaves should be observed and prevented in time. In case of occurrence, spray with 1000 times 40% dimethoate EC to kill scale insects and aphids. The moths were sprayed with 1 500 times 80% dichlorvos EC and the overwintering cocoons on the branches were removed in winter. In the early stage of development, the sawfly can catch adults with insect net

Chinese PinYin : Man Tang Hong