Detailed Explanation of Nectarine Planting Methods and Technical Key Points

Nectarine (Latin scientific name: Prunus persica var. nectarina), also known as peach-bergamot. Nectarine (English: Nectarine) is a variety of the common peach (whose skin is covered with fuzz), a small deciduous tree grown for its fruit. Nectarine originated in China and is distributed in both Asia and North America.

Planting Techniques

I. Soil Management

In mature orchards, the whole orchard can be planted with grass, or grass can be used to cover the tree disc with grass grown between the rows. During the growing season, no inter-row cultivation is done; weeds between rows are cut multiple times and laid over the tree disc. In winter, base fertilizer is applied in combination with expanding the planting holes, and trenches are dug around the outer edge of the tree disc to bury it deeply. Nectarine is afraid of waterlogging, so drainage ditches should be added around the orchard to prevent water accumulation. At the same time, deep plowing to improve the soil should be carried out year by year, so that the soil is loose and well aerated, which is conducive to root growth.

II. Fertilization

The amount of fertilizer applied should be determined according to the variety, tree age, tree vigor, yield and soil conditions. Generally, fertilizer is applied 3 to 4 times a year, mainly organic fertilizer, supplemented by chemical fertilizer. A nectarine orchard with a yield of 1500 kg per mu can apply 2000-4000 kg of barnyard manure, 30 kg of urea, 20 kg of potassium sulfate, or 20-40 kg of compound fertilizer.

1. Pre-bloom fertilizer (bud-breaking fertilizer)

Its purpose is to ensure nutrient supply for the tree's flowering, new shoot growth and young fruit stage, mainly nitrogen fertilizer, applied before bud break (late February to early March). The amount applied accounts for about 10% of the annual fertilizer amount; generally, 0.2-0.3 kg of potassium phosphate compound fertilizer + 0.1 kg of urea per tree. For trees that have just begun to bear fruit and trees with vigorous growth, it can be omitted to avoid excessive vegetative growth, which would affect fruit set.

2. Fruit-swelling fertilizer

Applied when physiological fruit drop basically stops and pit hardening begins (early May), it aims to promote fruit enlargement and increase single fruit weight. Mainly potassium fertilizer, the amount applied accounts for about 25% of the annual fertilizer amount; generally, 0.5 kg of potassium sulfate compound fertilizer per tree.

3. Post-harvest fertilizer

Applied after fruit harvest, it allows the tree to replenish nutrients in time, restore tree vigor, promote flower bud differentiation, improve flower bud quality, and create favorable conditions for a bumper crop the following year. Note that quick-acting fertilizer should be combined with slow-release fertilizer, and the amount applied accounts for about 30% of the annual fertilizer amount. Per tree, 3-5 kg of chicken manure and 1-1.5 kg of compound fertilizer can be applied; for trees with weak vigor, an additional 0.5 kg of urea can be added.

4. Base fertilizer

Mainly organic fertilizer, applied in mid-November after leaf fall when the root system is still at its activity peak; earlier is better than later. Mainly farmyard manure, the amount applied accounts for about 35%-45% of the annual fertilizer amount. Generally, 40-60 kg of pig manure or 20-25 kg of chicken manure, 2 kg of superphosphate, and 1 kg of potassium sulfate or compound fertilizer per tree.

III. Flower and Fruit Management

(1) Promoting flowering and protecting fruit

Nectarine generally has a high self-fruiting rate and good productivity. However, under rainy conditions in the south, young trees may drop flowers and fruit due to improper management measures such as excessive nitrogen application, overly heavy or overly light pruning, as well as abnormal weather such as low temperature and continuous rain during the flowering period.

For strong, vigorous trees, the amount of fertilizer should be reduced; in the first half of the year, no or little nitrogen fertilizer should be applied, and only phosphorus and potassium fertilizer should be applied, supplemented by the pruning principle of heavy pruning in summer and light pruning in winter. For vigorous new shoots, the tree vigor can be moderated and light conditions improved to increase the fruit set rate by pinching, twisting shoots and bending branches. In July to August, when new shoots grow longer than 60 cm, spray the leaves with a 300-fold solution of 15% paclobutrazol wettable powder, mainly spraying the growing points at the branch tips. Soil application can also be used; the amount applied is determined according to the tree crown projection area, generally 0.5-1 g of paclobutrazol per 1 sq m of tree crown projection area. Both methods can control shoot growth, help accumulate nutrients in the shoots, and promote flower bud differentiation.

Spraying 0.2% monopotassium phosphate plus 0.2% borax at the bud stage, and spraying 0.3% urea plus 0.2% borax plus 0.02% brassin at the flowering stage, has a good effect on protecting flowers and fruit of nectarine. Bees can also be released during the flowering period to attract bees for pollination and improve pollination quality; generally, 1 box of bees can be kept per 3-5 mu.

(2) Strict fruit thinning

Nectarine has a high natural fruit set rate and tends to bear excessive fruit. When too much fruit is set, the fruit becomes smaller, its commercial quality decreases, and it is not conducive to high-quality cultivation. Therefore, fruit thinning should be carried out in time. Fruit thinning is generally done in two rounds. The first is carried out about 20 days after flowering, when large and small fruits can be distinguished, removing poorly developed fruit, deformed fruit, overly dense fruit and small fruit; the second is carried out in mid-April when the fruit enters the swelling stage, keeping fruit according to the target yield standard of 1500-2000 kg/mu. Generally, 3 fruits are kept on long fruiting branches, 2 fruits on medium fruiting branches, and 1 fruit on short fruiting branches and flower-bunch branches.

IV. Training and Pruning

Nectarine trees are strongly light-loving, have a large growth volume, a high bud sprouting rate and strong branching ability. Through training and pruning, light should be reasonably distributed, a high-yielding tree shape should be cultivated, the contradiction between shoots and fruit should be moderated, fruit quality should be improved, and the economic life should be extended. The natural open-center shape is generally mostly used. The trunk height is 40-50 cm, with 3 main branches alternately borne on the trunk. The main branches are at an elevation angle of 45-50 degrees, and the outer angles among the 3 main branches are each 120 degrees. Try to make the third main branch extend due north, with 2-3 side branches borne on each main branch; side branches of the same grade should be selected and kept on the same side of each main branch. The first side branch is about 60 cm from the trunk, the first and second side branches are 50 cm apart, and the second and third side branches are 40 cm apart. Large, medium and small fruiting branch groups are cultivated on the main and side branches to complete the tree structure.

For fruiting trees, through methods such as thinning, retraction, renewal and pinching, the configuration and cultivation of fruiting branch groups should be well managed, achieving "few but excellent large branches, many but even small branches", with a neat crown, balanced top and bottom, clear layers, an open center, and three-dimensional fruiting.

(1) Summer pruning

After bud break, remove the water sprout buds at the pruning cuts and the buds on the back of main and side branches. In May, promptly remove back branches and overly dense branches, and control vegetative growth through pinching, twisting shoots and bending branches to promote fruit enlargement. During the fruit coloring stage, cut off shading branches and remove shading leaves to promote fruit coloring. After harvest, thin out water sprouts, overly dense branches and crossing branches to improve light conditions and promote flower bud differentiation.

(2) Winter pruning

For main branches that have not yet closed the rows, strong branches are still headed back as extension branches to expand the crown. After the rows close, some main branches can be retracted to improve ventilation and light conditions for the tree and the entire orchard. Pay attention to controlling the density of fruiting branch groups and renew them in time, and determine the amount of fruiting branches to retain. Remove overly dense and thin, weak branches; long fruiting branches are cut to retain 10-12 pairs of flower buds, medium fruiting branches are cut to retain 6-8 pairs of flower buds, and vigorous young fruiting trees can be left unpruned with long branches.

V. Crack Prevention Measures

Variety characteristics are the internal cause of fruit cracking in nectarine, while unsuitable climate, imbalanced water supply, imbalanced tree nutrition, sunscald and damage from pests and diseases are all external factors causing fruit cracking.

(1) Bagging

Carry out in mid-to-late April after physiological fruit drop ends and fruit thinning is completed. Before bagging, spray the whole orchard once with a 800-fold solution of 70% thiophanate-methyl wettable powder + a 1000-fold solution of 50% fenitrothion emulsifiable concentrate. Fruit bags with light transmission and good waterproof performance should be selected, such as Kobayashi NK-15. After bagging, fruit cracking caused by drastic changes in temperature and humidity due to rainwater and direct sunlight can be effectively prevented, and the appearance quality can be improved.

(2) Plastic film mulching

Carry out from the flower bud stage to the beginning of flowering; cover the ground with plastic film along the planting row. On rainy days, it can prevent rainwater from directly seeping into the soil of the tree disc, and on sunny days, it can reduce soil moisture evaporation, keeping soil moisture relatively stable, thereby achieving the purpose of preventing fruit cracking.

VI. Pest and Disease Control

Compared with fuzzy peach, nectarine has weaker disease resistance. The main pests and diseases include shot hole disease, brown rot, anthracnose, scab, top rot, gummosis, aphids, oriental fruit moth, etc. Cultivation management should be strengthened, vigorous tree vigor should be cultivated, attention should be paid to orchard ventilation, light and drainage, and emphasis should be placed on winter orchard cleaning and spring prevention.

Before flower buds sprout, spray 5 degrees Baume lime sulfur mixture or a 30-fold solution of 45% crystalline lime sulfur mixture. Before flowering or at the beginning of flowering, spray a 800-fold solution of 50% carbendazim wettable powder (or a 800-fold solution of 70% thiophanate-methyl wettable powder). After petal fall, spray a 800-fold solution of 80% Daconil M-45 wettable powder (or a 600-fold solution of 70% Antracol wettable powder, a 3000-fold solution of 10% Score water-dispersible granules, a 8000-fold solution of 40% Fuxing emulsifiable concentrate, a 5000-fold solution of 43% Topsin-M suspension concentrate, a 1000-fold solution of 80% Xinwansheng or Pencozeb wettable powder) + a 3000-fold solution of 10% imidacloprid wettable powder. Generally, spray once every 10-15 days, rotating the chemicals, until 15 days before harvest, and pay attention to the pre-harvest interval. For peach orchards with severe shot hole disease, an additional spray of a 1000-fold solution of 20% Zaijun wettable powder (or a 1000-fold solution of 20% Saigao wettable powder, a 1500-fold solution of 50% super copper water-soluble powder + a 1000-fold solution of 3% Kejunkang wettable powder) can be added.