High-position trunk-training technical measures and operational key points for navel orange

Navel orange is an excellent variety of fruit, rich in nutrients with a sweet and uniquely delicious taste, and is especially loved by the general public. So do you know how navel oranges are grown? What should be noted when cultivating navel oranges? Below, follow the editor to learn about navel orange cultivation techniques!

High-position trunk-training technical measures for navel orange

1. Trunk training. After the seedling is planted, cut the top at 60-80 cm from the graft union; the 20-40 cm or so below the cut bud is the shaping zone, and below the shaping zone is the main trunk. If the upper part of the seedling has 2 or more branches of similar position and comparable vigor, choose the strongest, most upright branch among them to cut the top, and for the remaining branches either adopt measures such as branch bending or ringing to weaken their growth vigor, or simply thin them out, to avoid disrupting the tree shape in the future. For the original weak small branches on the main trunk, retain them as much as possible; where original branches are insufficient, some sprouts can also be selected and used as auxiliary nurturing branches; for overly vigorous branches, technical measures such as branch bending or heavy heading back (cutting off the front 2/3 of the branch) combined with repeated pinching can be adopted to promote branching, weaken their growth vigor, and keep them as auxiliary nurturing branches. In short, as long as the branches on the main trunk are controlled so that their vigor does not exceed that of the main branches and sub-main branches and they do not disrupt the tree structure, they should be retained as much as possible to support tree growth. After the canopy has basically taken shape, gradually remove them as circumstances require.

2. Selecting and retaining main branches. Within the shaping zone, using the seedling's original branches or after new shoots sprout, select 3-4 strong branches to cultivate as main branches, and the remaining branches and buds should be removed as early as possible. The first main branch is about 40 cm above the ground, and the spacing between main branches is about 10-20 cm. The distribution of main branches in three-dimensional space should be even, and their growth vigor should be balanced. The angle between the main branch and the main trunk is 45-55°.

3. Arranging sub-main branches. After the main branches extend, select and retain 2-3 sub-main branches on them. The first sub-main branch is about 30 cm from the main trunk, and the spacing between sub-main branches is about 20 cm. Note that the growth vigor of sub-main branches should be weaker than that of the main branches. Sub-main branches on different main branches should not overlap or cross each other, making full use of space.

4. Retaining side branches. At appropriate positions on the main branches and sub-main branches, select and retain as many moderate or slightly weak branches as possible as side branches to support tree growth. Do not retain only the framework branches and no auxiliary nurturing branches.

Pollution-free cultivation techniques for navel orange

1. Hole expansion and soil improvement

The soil types in the mountainous and hilly areas of southern Jiangxi are mainly red soil, yellow soil and purple sandy soil, whose prominent characteristics are acidity, hardness, leanness, stickiness and drought. Therefore, whether establishing a new orchard on flat land, hills or mountains, the principle of improving the soil first and planting afterward must be adhered to. However, one deep plowing of the planting hole (trench) cannot solve the problem once and for all. As the root system extends, the canopy expands and the yield increases, the orchard soil must be continuously improved to raise fertility and maintain vigorous tree vitality. To achieve this goal, the entire orchard must be systematically expanded and improved in accordance with the growth and development patterns of the navel orange tree.

(1) Method: Hole expansion and soil improvement means deep digging outward along the outside of the planting trench or the previous expansion trench, with no wall left in between; roots may be encountered but excessive damage to fine roots should be avoided; the expansion trench is 50-60 cm wide and 60-80 cm deep; for each cubic meter, 20-30 kg of coarse organic fertilizer is buried in layers, and cake fertilizer, phosphate fertilizer, etc. are additionally applied near the canopy area.

(2) Timing: Hole expansion and soil improvement can be carried out in all four seasons, provided that roots are injured as little as possible. In practice, filling materials and labor should be arranged according to specific conditions and requirements and adapted to local conditions, completing orchard-wide soil improvement in 2-3 years. It should be avoided during the vigorous growth period of new shoots, the vigorous growth period of young fruit, periods when winter soil temperature is too low, and hot, dry seasons. In southern Jiangxi, bearing orchards generally carry out the work after the autumn shoots mature from September to November; for young, non-fruiting navel orange orchards, it can be carried out from after the spring shoots mature until mid-November.

2. Intercropping and grass growing

Growing grass in navel orange orchards can improve soil structure, continuously increase soil organic matter and fertility, and reduce chemical fertilizer input; prevent soil erosion, conserve fertilizer and water, and resist drought; regulate air temperature and help navel oranges maintain normal physiological activity; promote navel orange growth and significantly increase fruit yield and quality; attract large numbers of natural enemies, improve the biological control capacity of the navel orange orchard, reduce pest and disease damage and lower pesticide use. It is a technology promoted by the Ministry of Agriculture for green food fruit production and has been designated a national agricultural demonstration and extension project for introducing foreign intellectual achievements and a "948" agricultural technology introduction project.

Orchard intercropping: In young navel orange orchards, the canopy is small, so economic crops can be interplanted between rows, such as peanuts, legumes, Chinese milk vetch (red flower grass), and fodder radish; it is not suitable to interplant tobacco, corn, watermelon, sweet potato and other tall or vine-type crops.

(1) Natural grass growing: After thoroughly clearing malignant weeds from the navel orange orchard, naturally retain beneficial weeds outside the tree disk, such as dandelion, foxtail grass, and creeping thistle.

(2) Artificial grass planting: After thoroughly clearing field weeds, artificially plant grass species outside the tree disk that have strong adaptability, high fresh grass yield, short stems and shallow roots, and are conducive to the breeding and reproduction of natural enemies of pests, such as white clover, peanut grass, ryegrass, and Japanese clover; on terrace walls, bahia grass can be planted.

Pruning during the young tree period

During the young period of navel orange, there are relatively few branches and leaves, so on the basis of shaping, pruning and shoot removal should be minimized to increase the amount of branches and leaves and form a canopy as early as possible.

1. Heading back the extension branches of main branches and sub-main branches: To ensure strong growth vigor of the main branches and sub-main branches, before each shoot flush, lightly head back their extension branches (cut off about the front 1/3). Note the direction of the cut bud; slanting upward is best, and the cut should not be made at a bud facing upright inward or slanting downward.

2. Bud thinning: After heading back the extension branches of main branches and sub-main branches, if too many buds sprout at the tip, remove the weak small buds when the new shoots are 3-5 cm long, retaining 2-3 strong new shoots to maintain the growth vigor of the main branches and sub-main branches; if new shoots elsewhere are too dense, part of the weak small new buds should also be removed in a timely manner.

3. Pinching: Before each new shoot (mainly spring and summer shoots; autumn shoots are not pinched) self-prunes, retain 8-10 leaves and pinch off the tip to promote maturity.

4. Bud removal and shoot release: Before summer and autumn shoots sprout, first remove scattered sprouting new buds to promote uniform new shoot growth, making it easier to control citrus leafminer and canker disease.

5. Thinning: During the shaping process, if vigorous water shoots are found that seriously disrupt the tree shape and there is no space for them to develop around them, they should be removed in a timely manner.

Orchard fertilizer and water management

Navel oranges grow vigorously and have high fertilizer requirements. In the first 3-4 years before bearing, make full use of the gaps between rows to plant winter and summer green manure crops; apply heavy organic fertilizer, mainly green manure, livestock manure, biogas slurry, bran cake, and biological organic compound fertilizer; adopt grass growing cultivation, green manure mulching and water-saving irrigation techniques; supporting ecological cultivation facilities such as pig pens, biogas digesters and fish ponds (storage ponds) should be built in the orchard to form a pig-biogas-fruit ecological orchard.

After orchard establishment, in 3-4 years, combine orchard-wide pit expansion and soil improvement to apply organic fertilizer deeply, mainly compost, barn manure, cake fertilizer and green manure, applying 30-50 kg per tree each time; for young trees, topdressing should mainly focus on shoot-pushing, shoot-promoting and shoot-strengthening fertilizer, following the principle of frequent application and light application.

Through the above content, we have all learned about navel orange cultivation techniques. Navel orange is an excellent variety of orange, rich in nutrients, delicious and juicy, with particularly high utility value. The prospects for growing navel oranges are broad, so those who want to start a business or grow agricultural products might as well give it a try; perhaps it will bring you quite a few surprises!