How should peach trees be cultivated in protected facilities?

1. Variety selection 

Nectarine and peach varieties suitable for protected cultivation mainly include Shuguang (Huaguang, Yanguang), Zaohong No. 2, Weifang sweet nectarine, Annong Shuimi, Chunyan, Qingyan No. 1, Zaolu flat peach, Yuhualu, Shazi Zaosheng, etc. The rootstock is wild peach rootstock or Dongxue honey peach.

2. Orchard establishment 

1. Site selection and soil improvement (1) Site selection The selected site must first of all have convenient transportation, which is good for market circulation, and is best close to major transport routes, large and medium-sized cities, factories and mines; the terrain should be relatively high, without water accumulation, and the groundwater level in the rainy season should not be higher than 80 cm to 100 cm; it should face the sun and be sheltered from the wind, with no tall buildings or trees around that cause serious shading; drainage and irrigation should be convenient; the soil type should preferably be loose sandy loam or loam, and continuous cropping land, saline-alkali land and clay land should not be used. (2) Soil improvement For heavy clay or strongly sandy soil, mix in sand or clay to improve it, and break through the underground impermeable clay pan layer and silt layer. The focus of improvement is to increase the application of organic fertilizer. Combined with deep plowing of the soil, apply 6000 kg to 8000 kg of high-quality decomposed barnyard manure per mu or 3000 kg to 4000 kg of decomposed chicken manure. Organic fertilizer contains comprehensive nutrients in a reasonable ratio, and more importantly, it can improve soil structure, promote the formation of soil aggregates, create a coordinated environment of water, fertilizer, air and heat, and benefit the occurrence of fruit tree roots, especially absorbing roots. In addition, large amounts of organic fertilizer can enhance the buffering capacity of the soil and prevent soil salinization. 

2. Planting density A spacing of 1 m × 2 m between plants and rows is suitable. 

3. Planting pattern Ridge planting. Use 1-year-old rapid-growth seedlings. Dig planting trenches 1 m wide and 0.5 m deep; when the soil is compacted, it should be deepened appropriately. Place topsoil and subsoil separately. When backfilling, first mix topsoil with sufficient decomposed organic fertilizer and an appropriate amount of phosphorus and potassium fertilizer and fill it in; when the fill is 20 cm to 30 cm from the ground, add the subsoil to prevent fertilizer from burning the roots. Plant the seedlings somewhat shallowly, irrigate after planting, and after the water seeps down, cover with soil and form ridges after 1 day to 2 days. After planting, determine the trunk height, with a trunk height of 30 cm to 40 cm, lower in the south and higher in the north.   

3. Promoting growth and flowering 

“Promote early, control late” is the key technology for peach trees to achieve “three in the same year,” namely planting in the current year, covering the shed in the current year, and achieving high yield in the current year. “Promote early” means promoting growth in the early stage; before July 15, all management measures are aimed at promoting vegetative growth, rapidly expanding the canopy. “Control late” means promoting flowering in the later stage; after July 15, all management measures are aimed at controlling tree vigor and promoting flower bud differentiation. 

1. Growth-promoting measures (1) Fertilizer and water management When new shoots grow to 15 cm to 20 cm, begin topdressing with quick-acting fertilizer, alternating underground topdressing and foliar spraying. Underground topdressing is usually 40 g to 50 g of urea per plant, and foliar spraying uses 0.3% urea and 0.4% to 0.5% monopotassium phosphate. Apply once every 10 days to 15 days, for 2 to 3 consecutive times. Combine topdressing with watering, and also water according to soil moisture conditions. (2) Pinching to promote canopy formation Cultivate a multi-main-branch open-center shape. In mid-to-late May, select 4 to 6 new shoots with good vigor and angle to train as reserve branches, and remove the remaining new shoots. In early to mid-June, when new shoots grow to about 40 cm, pinch them (cut off 10 cm to 20 cm from the tip) to promote secondary branches, increase branch number, and expand the canopy. 

2. Flower-promoting measures (1) Fertilizer and water management After mid-July, stop underground topdressing, spray 0.3% monopotassium phosphate once every 10 days, for 2 to 3 consecutive times. If soil moisture is good, generally do not water; pay attention to drainage during the rainy season. (2) Promoting flowering with PP333 From mid-to-late July to early August, spray 15% pp333 200 times to 400 times solution once every 10 days to 15 days, for 2 to 3 consecutive sprays, which can effectively inhibit excessive new shoot growth and promote flower bud differentiation. (3) Summer pruning In mid-July, bend branches. Select 3 to 4 reserve branches to train as permanent main branches and bend them to a 60-degree to 70-degree angle; bend the remaining reserve branches flat as auxiliary nurturing branches. Upright vigorous shoots on the main branches should be promptly twisted and stroked to control them, and removed when too dense. 

4. Selection of facility type 

Facility types suitable for protected cultivation of peach trees include plastic-film solar greenhouses (used for winter forcing cultivation) or plastic tunnels (used for advancing cultivation in spring or delaying cultivation in autumn). Different regions may choose different facility types according to actual conditions.   

5. Management before covering the shed 

1. Fertilizer and water management In the year of planting, on the basis of applying sufficient base fertilizer, do not apply organic fertilizer again in autumn. However, for trees that have already borne fruit, apply organic fertilizer and compound fertilizer once from mid-September to mid-October, with an application rate of 1000 kg of decomposed chicken manure per mu or 2000 kg to 3000 kg of barnyard manure, plus 65 kg of potassium sulfate compound fertilizer. Water thoroughly 20 days to 30 days before covering the shed, and cover the whole orchard with plastic film.  

 2. Winter pruning before covering the shed Further adjust the tree structure, and remove non-flowering vegetative branches, diseased and insect-damaged branches, overly dense branches, overlapping branches, and competitive branches at the extension head. The amount of branch removal should be less than 10% of the total branch amount, so as not to destroy the growth balance between the aboveground and underground parts. Implement long-branch pruning; except for lightly heading the main branch extensions, the remaining retained branches are generally not headed.