Key Techniques for Site Selection, Orchard Establishment, and Fertilizer and Water Management of Navel Orange

Navel orange, original name: sweet orange. Aliases: Huangguoshu, orange, navel orange, fragrant orange, chenggzi. Latin name: Citrus sinensis (L.) Osbeck. Sapindales, Rutaceae, evergreen small tree, branchlets hairless, branch thorns short or absent. Leaves elliptical or ovate, entire or with inconspicuous blunt teeth; petiole narrowly winged, apex articulated. Navel orange is a fine citrus variety cultivated competitively around the world. At present, many high-quality navel oranges are also cultivated in various parts of China. Navel orange is rich in nutrients and contains various nutrients essential to the human body. Navel orange contains a large amount of vitamin C and carotene, helps inhibit the formation of carcinogens, and can also soften and protect blood vessels, promote blood circulation, help lower cholesterol and blood lipids, reduce the possibility of heart disease, and prevent gallbladder disease. Navel orange is rich in vitamins and can prevent the occurrence of scurvy. The fruit is orange-yellow with green stripes. Suitable for pot cultivation, it is an excellent product for foliage and fruit appreciation.

Select good varieties and strong seedlings. For planting navel orange, varieties with excellent comprehensive traits such as Newhall should be selected. Seedlings should be free of pests and diseases, with a trunk thickness of more than 0.8 cm and 2-3 branches.

Site selection and orchard establishment, reasonable close planting. Generally, a mountain site with sufficient water source, convenient transportation, facing south with the north at the back, deep soil layer, and fertile and loose soil can be selected for orchard establishment. When establishing an orchard on sloping land, terraces should be well opened, generally with a belt width of more than 2.5 m, and planting holes 1 m in length, width, and height; trenches 80 cm deep and 1 m wide can also be dug for planting. The planting specification for navel orange is row spacing 1 m × 1.5-2 m, and the planting time is before spring shoot sprouting or after autumn shoots mature.

Fertilizer and water management

Apply sufficient base fertilizer: apply 25-40 kg of weeds, 1.5 kg of superphosphate, 1.5 kg of lime, and 1.5 kg of chicken manure or bran cake per plant, buried in 3-4 layers from coarse to fine, one layer of soil and one layer of fertilizer, with lime sprinkled on the fertilizer surface, filling to eight-tenths full of the hole, and apply the composted chicken manure or bran cake (composted with a little superphosphate for 3 months) on the top layer of the planting hole, then make a mound 30 cm above the ground and 70-80 cm wide for planting, to prevent sinking and water accumulation.

Fertilization for young trees: 1-2 year old navel oranges are fertilized 6-8 times each year, with emphasis on applying shoot-promoting fertilizer and shoot-strengthening fertilizer for the 3 shoots of spring, summer, and autumn. Shoot-promoting fertilizer is applied 10 days before shoot emergence, mainly nitrogen fertilizer; for 1-year-old trees, use 25-50 g of urea per plant, and for 2-year-old trees, use about 0.1 kg of urea per plant, applied together with manure water or decomposed bean bran water. Shoot-strengthening fertilizer is applied during the new shoot elongation period, mainly phosphorus and potassium fertilizer; for 1-year-old trees, apply 75 g of compound fertilizer per plant, and for 2-year-old trees, apply 0.1 kg per plant.

Fertilization for mature trees: navel orange begins to bear fruit in the third year after planting, and fertilization is carried out throughout the year as bud-promoting fertilizer, fruit-strengthening fertilizer, autumn shoot-promoting fertilizer, and post-harvest fertilizer. Bud-promoting fertilizer is applied in late January, with 0.1 kg of urea, 0.2-0.3 kg of compound fertilizer, 50 g of borax, and 50 g of magnesium sulfate per plant; fruit-strengthening fertilizer is applied in late May after the second physiological fruit drop of navel orange, with 0.4-0.75 kg of compound fertilizer plus 75 g of potassium sulfate per plant; autumn shoot-promoting fertilizer is applied in late July, with 0.25 kg of urea and 1 kg of compound fertilizer drenched per plant; post-harvest fertilizer is applied 3 days before harvest, with 0.25 kg each of urea and compound fertilizer drenched per plant.