Is dry land suitable for growing Sichuan pepper trees? Which varieties are good to plant? When to plant? How to plant?
Sichuan pepper, also known as large pepper, Qin pepper, and Shu pepper, is a common tree in most parts of China. It is widely cultivated because of its high edible and medicinal value, and it is now grown in most parts of the country. So is dry land suitable for growing Sichuan pepper trees? Which varieties are good to plant? When to plant? How to plant?
Dry land is suitable for growing Sichuan pepper trees, because Sichuan pepper is drought-tolerant and likes sunlight, and can be planted on plains or in mountainous areas at higher altitudes.
Suitable varieties to plant:
1. Large-type Sichuan pepper: Dajiao, Shizitou, Dahongpao, Zhenglujiao, Wawajiao;
2. Small-type Sichuan pepper: Xiaojiao, Xiaohongjiao, Xiaohuangjin, Maojiao, Doujiao, Huojiao, etc.;
3. Other Sichuan peppers: Qiuzajiao, Baishajiao, Gaojiaohuang, Goujiao, Choujiao, etc.
Planting time:
The conventional sowing time is from the end of September to early October, and either broadcast sowing or drilling can be used. After sowing, cover with fine river sand with a particle size of 1-2mm or cover with wheat straw, preferably so that the soil is not visible, to help preserve soil moisture, prevent crusting, and improve the emergence rate; in addition, growers have also worked out a method in production in which the fruit is harvested and dried in the shade, then sown immediately the same day. This method no longer requires seed treatment, and the emergence rate is also relatively high.
Planting techniques:
1. Selection of seedling-raising land
The seedling-raising land for Sichuan pepper should be selected in a place with fertile soil, good drainage, and convenient transportation. To improve the quality of seedlings for afforestation, it is best to choose a site near the planned orchard. This not only reduces the cost of transporting seedlings, but also ensures seedling quality and reduces the time from lifting seedlings to planting, thereby increasing the survival rate after planting.
2. Seed collection
When collecting seeds, choose Sichuan pepper trees that are in full fruiting stage with good varieties, vigorous growth, and high yield.
3. Seed treatment
Sichuan pepper seeds have a waxy layer on the outer shell, making it difficult for them to germinate in the same year. During seedling raising, the wax must be removed before the seeds can absorb water and germinate. Seeds can be soaked in a 3%-5% edible sodium carbonate solution for 3-4h, then rubbed and washed with fine sand with a particle size of 2-3mm to directly remove the wax. The wax can also be removed by mixing with fresh cattle or sheep manure and piling it for fermentation, or by soaking in a laundry detergent solution.
4. Thinning and final singling of seedlings
When the seedlings grow to 4-5cm, thin them; when the seedlings are about 10cm tall, final singling is done. Thinning and final singling should strictly follow the principle of “keep the strong and remove the weak, keep the tall and remove the short, keep the healthy and remove the diseased”, and can be carried out together with loosening the soil and weeding.
Sichuan pepper planting methods
1. Planting time
Sichuan pepper trees can be planted in two seasons, spring and autumn, but it is best to plant around “Spring Equinox” in spring. Spring planting should be carried out before the seedlings sprout. When planting pepper seedlings in autumn, part of the tender shoots and tender leaves should be removed to reduce water evaporation and improve the survival rate.
2. Seedling selection
When establishing a Sichuan pepper orchard in mountainous areas, 2-year-old seedlings should be selected, preferably dryland seedlings, with a ground diameter of about 1cm. The root system must be complete. There are no strict requirements for plant height, but there must be no rotten branches or leaves and no pests or diseases. Varieties can include local fine varieties such as Dahongpao, Dahongjiao, Xiaohongjiao, Baishajiao, Doujiao, and Qin'an No. 1.
3. Planting density
Sichuan pepper planting must not be too dense. Generally, 4m×6m or 6m×6m is suitable. To improve land utilization and increase income, crops such as peanuts, Codonopsis pilosula, vegetables, and potatoes can be intercropped in the early stage of orchard establishment.
4. Planting method
When planting Sichuan pepper, seedlings should be planted as soon as possible after being lifted. Spring planting must be carried out before the seedlings sprout. If transport is needed, the roots of the seedlings should be placed in plastic bags (the whole plant must not be placed in a plastic bag). When planting, dig large holes and apply sufficient base fertilizer. Generally, the planting hole is 50-60cm3, and each hole is given 3-5kg of farmyard manure and 50g of superphosphate. The fertilizer must be mixed evenly with the soil, and 100g of fresh lime powder should be added to prevent root rot. When planting, use the method of “first bury, second tread, third lift the seedling”. After planting, water with settling water, and after the water has completely infiltrated, cover with dry soil to preserve moisture.
Later field management techniques
1. Fertilization
When planting young trees, a small amount of phosphate fertilizer can be applied to promote root growth. After that, a small amount of urea can be applied each year along with loosening the soil. When controlling pests and diseases, potassium dihydrogen phosphate can be used for foliar topdressing. Once the trees enter the full fruiting stage, after fruit harvest each year, open a ring-shaped ditch below the outer edge of the canopy and mix organic fertilizer and compound fertilizer into it. Apply about 0.25kg of compound fertilizer and about 15kg of organic fertilizer per tree, which can ensure the tree's nutrient consumption.
2. Winter management
Sichuan pepper trees have relatively weak cold resistance, so attention must be paid to winter climate changes, wintering management of the pepper trees must be done well, and normal growth of the pepper trees must be ensured.
For young Sichuan pepper seedlings, methods such as wrapping with straw and pressing and burying can be used. That is, before winter arrives, wrap the trunk with wheat straw or straw bags, then bind it externally with plastic film to avoid freeze damage; or pile soil beside the roots, then slowly press the whole tree down and cover it with about 20cm of soil, and promptly remove the warming measures before the seedlings sprout in spring. For larger pepper trees, methods such as whitewashing, watering, and spraying plant ash liquid can be used to prevent freeze damage.
In recent years, late frost has been common in Gangu County, causing huge losses to the growth and fruiting of Sichuan pepper trees. In response to this natural phenomenon, weather forecasts should be listened to in time, and the method of lighting smoking piles should be adopted to recover losses. Generally, 75-90 piles of semi-wet firewood and grass per hm2 is sufficient. Light them after 12 o'clock at night. Someone should watch over them and pay attention to fire prevention.
3. Flower preservation and fruiting
During the flowering period of Sichuan pepper trees, never spray with dimethoate emulsifiable concentrate, otherwise fruit drop will be very serious. Potassium dihydrogen phosphate plus urea water solution can be sprayed during the flowering period to prevent flower and fruit drop. At full bloom, spray gibberellin 10mg/kg on the leaves; at full bloom and mid-bloom, spray 0.3% potassium dihydrogen phosphate plus 0.5% urea water solution; after flower drop, spray 0.3% potassium dihydrogen phosphate plus 0.7% urea water solution every 10 days.
Pruning can be carried out together with fruit harvesting, or from late autumn onward during the dormant period.
4. Pruning methods
In the year the young tree is planted, at about 30cm above the ground, choose a plump bud and cut off the trunk above it. Then, among the branches that emerge from the base, keep three or four branches according to orientation with evenly staggered angles and train them as main branches, removing the remaining branches. On the main branches, gradually train side branches year by year. On each main branch, 5-8 side branches can be cultivated according to the tree's growth condition, and three or four groups of fruiting branches can be cultivated on the side branches. Generally, branches on the upper side and lower side of the main branches are not kept.
In daily management and care, diseased and pest-damaged branches, overlapping branches, and sprouting branches should be removed in time. For water sprouts, they can be left unpruned for a long time. Those that can be utilized by bending should be fully utilized, and those that cannot be utilized should be removed in time to reduce the consumption of water and nutrients.