Management Methods for Early Fruiting and High Yield of Navel Orange in the Third Year After Planting

Before planting navel orange seedlings, careful land preparation must be carried out by digging large holes or trenching, and sufficient base fertilizer must be applied. After the planted seedlings survive, the following measures are mainly used to promote fruiting and high yield in the third year.

Scientific fertilization. Navel orange seedlings planted in the current year generally survive in half a month. After survival, apply a quick-acting fertilizer once every half month, watering with dilute manure water or 0.5% urea, or after rain apply 25 grams of urea per plant under the tree canopy, then loosen the soil around the tree plate to facilitate root absorption. After August, quick-acting fertilizer should no longer be applied, so as to avoid the growth of late autumn shoots. In the second year, topdress 3 times, with heavy application of fertilizers for spring, summer and autumn shoots. Spring fertilizer in early February, summer fertilizer in early to mid-May, and autumn fertilizer in mid-to-late July, applying 0.2-0.4 jin of urea per plant each time. After the autumn shoots mature, expand the holes and heavily apply base fertilizer, applying 10-20 jin of barnyard manure, 2 jin of superphosphate, and 1 jin of compound fertilizer per plant. In the third year, as young trees begin to bear fruit, increase the application of phosphorus and potassium fertilizers and organic fertilizers to meet the needs of flower and fruit development. In early February, apply 0.4 jin of urea per plant as a bud-promoting fertilizer, and at the same time, from April until early August, carry out foliar topdressing about once every 20 days, mainly with a mixed solution of 0.2% monopotassium phosphate + 0.3% urea + 0.2% borax + zinc sulfate, or special micro-element fertilizer. In early July, apply 2 jin of compound fertilizer per plant as a fruit-strengthening fertilizer, and in autumn apply a restorative fertilizer, gradually cultivating and managing according to the conventional fertilization methods for adult trees.

Reasonable shaping and pruning. Young trees must be trained into a good tree shape. Do not prune branches indiscriminately. Generally, methods such as bud rubbing, shoot thinning, and heading back are used to promote the growth of more branches. Specific operation methods: in principle, do not use pruning shears in the first year, only remove diseased and pest-infested branches and dead branches; in the second year, keep a trunk of about 25 cm for the seedling, and within the shaping zone above the trunk cultivate 3-4 main branches distributed evenly. Do two summer pruning operations well. The first is in mid-May, heading back one third of the mature spring shoots on the outer canopy to promote strong summer shoots. The second is in mid-July, lightly pinching the mature summer shoots on the outer canopy. In mid-June, pinch the summer shoots while keeping 6-8 leaves, continuing until mid-July. For drooping branches and inner canopy branches, retain them as much as possible. If the canopy is relatively dense and one side grows excessively, use ropes to pull apart 2-4 main branches. In the second year, if there are flower buds, remove them in time. In the third year, focus on flower thinning, thinning leafless flowers and deformed flowers, cutting off diseased and dead branches, and at the same time adopt some fruit-preserving measures. The yield per plant is generally controlled at about 5 kg to 8 kg, and excess fruit should be removed.

Auxiliary management. After young seedlings are planted, in the current year use rice and wheat straw to cover the tree plate, which plays a role in preserving moisture and protecting the seedlings. In winter, before a cold wave arrives, large convenient bags can be used to cover the young seedlings, or straw can be used to cover the branches, and whitewash can be applied to the trunk. In orchards, intercropping with leguminous crops is encouraged, or the orchard grass-growing method may be adopted. Pest and disease control is basically the same as for adult trees. In the third year, corresponding flower-thinning and fruit-preserving measures should be taken to ensure early high yield in that year.