Nurbolat Aidarhan, Yanhua GAO, Abulimiti Yili, Huixia NING, Geyu LIU, Haji Akber Aisa

Key Laboratory of Plant Resources and Chemistry of Arid Zone, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China

Abstract Salix carmanica Bornm (Salicaceae) is a tree plant and mainly produced in Hotan and Kashgar of Xinjiang, with the characteristics of drought resistance and super vitality. It is widely used in sand control and desert greening, and is one of the first-selected tree species for sand control, afforestation and ecological environment improvement. S. carmanica Bornm is also one of the genuine medicinal materials in Xinjiang, with pharmacological effects such as clearing away heat, diminishing swelling, promoting secretion of body fluid to quench thirst, reducing adverse effects, stopping vomiting and lowering blood pressure. In order to protect the ecology and tap the authentic medicinal resources in Xinjiang, this article focuses on the utilization value and cultivation techniques of S. carmanica Bornm.

Key words Salix carmanica Bornm, Xinjiang genuine medicinal material, Utilization value, Cultivation technique

1 Introduction

SalixcarmanicaBornm (Salicaceae) is a tree plant and mainly produced in the southern areas of Xinjiang such as Hotan and Kashgar. It grows fast, the branches droop naturally, the tree shape is graceful, fluttering with the wind, and the posture is whirling and chic, with a unique ornamental value.S.carmanicaBornm has the characteristics of drought resistance and super vitality. It is widely used in sand control and desert greening, and is one of the first-selected tree species for sand control, afforestation and ecological environment improvement. The fiber content ofS.carmanicaBornm is high, so it is a good raw material for paper making and artificial cotton. The flowers ofS.carmanicaBornm have medicinal value. The flowering branches are light yellow, light in weight, crisp and fragrant, and have a light taste[1].S.carmanicaBornm is a genuine medicinal material commonly used in Xinjiang folk, with pharmacological effects such as clearing away heat, reducing swelling, promoting secretion of body fluid to quench thirst, reducing adverse effects, stopping vomiting and lowering blood pressure.

At present,S.carmanicaBornm is mainly propagated through seedling raising and cutting. Cutting has the characteristics of low cost, high survival rate and simple operation, and will become the main method for the seedling nursery and promotion ofS.carmanicaBornm. To protect the ecology and expand the resources of genuine medicinal materials in Xinjiang, the characteristics and cultivation techniques ofS.carmanicaBornm are discussed in this article.

2 Morphological characteristics

S.carmanicaBornm (Salicaceae:SalixL.: Sect. Helix Dum.) is a tree plant, 5-6 m high, and bluish-green and smooth in bark. Branchlets are pale yellow, glabrous, slender and drooping. Leaves are oblanceolate, 3-5 cm long, 5-7 mm wide (sprout leaves are slightly larger), short and acuminate in apex, and wedge-shaped in base, with fine teeth on the edge. The color of the two sides of leaves is nearly the same. The young leaves are slightly fluffy, and the adult leaves are nearly glabrous. The stipules are linear, about 2 mm long, with fine teeth on the edges and early fall. Flowers and leaves spread nearly simultaneously. Female inflorescences are 1.0-2.5 cm long. Peduncles are about 1 cm long, hairy, with 2-3 small leaves. Bracts are light yellow-green, obovate, about 1.5 mm long, truncated and slightly concave in apex, glabrous outside, shed when fruit is ripe.S.carmanicaBornm has one gland that is small and belly-born. Ovaries are thin conical, slightly hairy or glabrous. Stalks are about 1 mm long. Styles are about 0.4 mm long and the stigma is 2-4 lobed. These are not seen in male plants[1-2]. Flowering period is from April to May. It is mainly produced in Hotan and Kashgar areas in Xinjiang, and is also found in Iran and Afghanistan. The flowers ofS.carmanicaBornm have medicinal value and are commonly used genuine medicinal material in Xinjiang folks. It is also a beautiful ornamental tree.

3 Utilization value

3.1 Medicinal valueThe flowers ofS.carmanicaBornm have medicinal value and are the genuine medicinal material commonly used in Xinjiang folks. Dried inflorescences ofS.carmanicaBornm are a common medicinal material of the Uyghur people, with the effects of clearing away heat, reducing swelling, promoting secretion of body fluid to quench thirst, reducing adverse effects, stopping vomiting, and lowering blood pressure[3].

3.2 Ornamental valueS.carmanicaBornm grows fast. The branches droop naturally, endowing the tree with a beautiful shape, fluttering with the wind. The posture is chic.S.carmanicaBornm has unique ornamental value. It can be used as a street tree, garden shade tree or planted solitarily on the grass, next to the building. In urban greening, the excellent clone ofSalix×aureo-pendulacan be used to gradually update the existing weeping willow female plants, which not only reduces the environmental pollution of catkins, but also greatly increases the landscape effect[1].S.carmanicaBornm is also one of the first-selected tree species for sand control and afforestation.

3.3 OthersWillow is light, easy to cut, does not deform after drying, and has no special smell. It can be used for construction, pit wood, box board and matchsticks. The wood has high fiber content, and is a raw material for papermaking and artificial cotton. Wickers can be woven baskets, boxes, hats,etc. Willow leaves can be used as fodder for sheep and horses. Willow is a nectar plant[2].

4 Distribution and growth environment

4.1 Distribution rangeS.carmanicaBornm is mainly distributed in Hotan, Moyu, Pishan, Kashgar, Shadong, Baluntai and other places in southern Xinjiang. It is mostly cultivated in gardens, without large-scale cultivation or cultivation bases.S.carmanicaBornm is also distributed in Iran, Afghanistan, and so on.

4.2 Growth environmentS.carmanicaBornm likes loam or sandy loam with high temperature, adequate sunshine, pH 7-8 and altitude 600-1 500 m.S.carmanicaBornm is tolerant to drought and flood, and it is a hygrocolous and heliophilous tree species.S.carmanicaBornm has drought resistance and super vitality, so it is suitable for desert greening, and is a sand control tree species.

5 Nursery and seedling management

The cutting technology ofS.carmanicaBornm has low cost, high survival rate, simple operation and strong practicability, and it will become the main method for the cultivation and promotion ofS.carmanicaBornm. Cutting experiments ofS.carmanicaBornm have been conducted repeatedly in recent years, and are summarized as follows.

5.1 Cutting timeS.carmanicaBornm should be planted in the spring when the flowers bloom, because spring is very suitable for plant growth regardless of air humidity and light. AfterS.carmanicaBornm plant germinates, spreads the leaves, blooms and bears fruit from March to mid-April, cutting can be carried out after the flowers are harvested in late April. It is best to choose fine woody cuttings of more than one year old as cutting materials.

5.2 Cutting and soil preparationSturdy branches that have uniform growth and are free from pests and diseases are cut. The cuttings should be above 0.8 cm in diameter and have a length of 15-17 cm, and each cutting should retain more than 2 buds. The upper incision is cut into a flat cut about 1.5 from the top of the bud, and the lower incision is a double-cut face incision to increase the surface area of the cutting base to absorb water and nutrients, increase the amount of callus, and promote the germination and growth of cutting roots[7]. Every 50 or 100 cuttings are bundled. The cuttings are soaked in clean water for more than 72 h for later use. Before cutting, the cuttings are dipped quickly in ABT2 rooting liquid (180 mg/L) to significantly promote the rooting rate to increase the survival rate.

The land must be prepared before cutting, including plowing, raking, leveling and compacting. Deep ploughing and fine trimming are required. Grass roots and stones are removed. The day before the cutting, 0.3% potassium permanganate solution is sprayed to the seedbeds for disinfection, increasing the survival rate of the cutting seedlings while preventing and controlling the diseases and pests.

5.3 Cutting methodThe processed cuttings are directly inserted into the field or in the full-light spray bed, at a plant spacing of 15-20 cm and a row spacing of 30 cm × 50 cm, in a north-south direction. The cuttings are inserted into the soil obliquely from north to south. The top of the seedlings is parallel to the ground, and the depth is 12-15 cm. After inserting, the soil around the cuttings is compacted, followed by irrigation or water spray. The temperature of the soil should not be lower than 15 ℃ during cutting. The humidity should be suitable. The interval between the first 3 irrigations is 7-10 d.

5.4 Fertilization and weedingWhen the seedlings grow to 10 cm, 0.2%-0.3% potassium dihydrogen phosphate and urea are sprayed to the leaves. They are sprayed once a week, for two consecutive weeks. Foliar fertilizer should be applied every 15 d and weeds and unsurvived cuttings should be removed timely.

Seedlings cultivated by cutting method can have a diameter up to 0.8 cm and a height up to 80 cm. Sturdy seedlings can be sold or transplanted to the field in the spring of the coming year.

6 Cultivation management

6.1 Afforestation time and afforestation land selectionIn southern Xinjiang, the cuttings can be transplanted intermittently in the morning and evening of sunny days or transplanted on cloudy days in March and April. Before transplanting, holes (20 cm×20 cm×20 cm) are prepared. The plant spacing should be 3-4 m, and the row spacing should be 4-5 m. Sufficient base fertilizer is applied. Irrigation is carried out in time after transplanting.

6.2 Seedling planting and managementIt is advisable to pull out seedlings on a cloudy day. Before pulling, water is poured to the seedlings thoroughly. The seedlings are moved gently during transportation. The seedlings are best to be transported and transplanted immediately after pulled out, to increase the survival rate of the seedlings. Each seedling is gently put in the holes, let stand upright in the center of the holes, and buried with soil. The backfilled soil is compacted to make the seedlings and the soil close together. The seedlings are watered thoroughly after planting. Daily management such as soil loosening, weeding, and watering should be done well. In the second year, combined with weeding, topdressing is carried out 1-2 times (50 g compound fertilizer or 10-20 kg organic fertilizer per plant each time).

7 Disease and pest control

Common pests during the seedling period ofS.carmanicaBornm are mainly scarab larvae (grubs), snails,etc. Drugs should be used for pest control. For the control of scarab larvae (grubs), solution of 40% methylphoxim (1 500× - 2 000×) can be poured, once every 5-10 d, for 2-3 consecutive times. To prevent snails, dry fine soil (10-15 kg) and 3% metaldehyde granules (1.5-3.0 kg) can be mixed and sprinkled evenly on the field. Rotted leaves and diseased plants should be removed timely to prevent root rot. To prevent infection by bacteria, 0.5% carbendazim solution can be sprayed once every 10-15 d.