Detailed Explanation of Key Citrus Spring Management Techniques

First, clear away dead branches and fallen leaves, weeds, dropped fruit, etc. from the orchard, and plow the soil to a depth of 15-20 cm. Then fertilize the fruit trees, irrigate, drain, and prune. In dry and hot weather, irrigate promptly; in rainy weather, drain excess water promptly. Spring is a season with frequent pests and diseases, and there are many types of pests and diseases during the flowering and young fruit stages, so prevention and control work must be done well.

1. Orchard Cleaning

Clear away dead branches and fallen leaves, weeds, dropped fruit, etc. from the orchard, and bury them deeply or burn them in a centralized manner. The orchard soil should also be shallowly plowed to a depth of 15-20 cm to loosen the soil and enhance soil permeability.

2. Fertilization

For young trees planted and established in the previous autumn, apply a shoot-promoting fertilizer once before the spring shoots sprout, mainly by foliar spraying, supplemented by ground application. The fertilizer should be mainly nitrogen fertilizer, appropriately combined with phosphorus and potassium fertilizers, to promote root growth and encourage young trees to produce more new shoots.

For mature trees, from late January to mid-February, apply 0.2 kg of urea and 0.2-0.3 kg of compound fertilizer per tree. Apply fertilizer once before flowering, mainly nitrogen, appropriately combined with phosphorus and potassium fertilizers. At full bloom, spray boron fertilizer, adding 0.3% urea solution for foliar spraying.

3. Watering

Spring is rainy, so excess water should be drained promptly to avoid affecting root growth or even causing root rot, which can lead to flower and fruit drop; if there is continuous dry and hot weather for more than 10 days, irrigate promptly to keep the soil moist.

4. Pruning

For young trees, the main goal is to train the tree shape, expand the canopy, select the central leader and main branches, and carry out heading cuts.

For trees that have just begun fruiting, the main goal is to train the canopy and balance tree vigor. Adopt pruning that is heavy at the top and light at the bottom, and heavy outside and light inside, to promote new branches, and appropriately thin out excessive spring shoots.

For trees in full fruit production, after temperatures rise, thin out fruit-stem branches, dead branches, densely growing branches, crossing branches, and pest- and disease-damaged branches; retract or head back long fruiting branches; during the flowering period, head back excessively long flower-bud branches; thin out leafless flower branches shorter than 5 cm, densely growing flower branches, and clustered spring shoot buds; and pinch off spring shoots when they grow to 7 leaves.

5. Flower and Fruit Preservation

From flowering to the end of blooming, promptly shake off opened petals to prevent petals from rotting and sticking to young fruit on rainy days, which helps young fruit turn green, improves fruit set rate, and can also reduce the occurrence of gray mold. At full bloom and at the end of blooming, if disaster weather such as “dry hot wind” or “late spring cold” occurs, use plant growth regulators to preserve flowers and fruit.

6. Pest and Disease Control

There are many types of pests and diseases during the flowering and young fruit stages, so pest and disease prevention and control work must be done well. Pests and diseases include anthracnose, scab, canker, flower bud midge, psyllid, leafminer, aphids, red spider mites, thrips, etc., and can be controlled by spraying lime sulfur mixture or pesticides such as chlorpyrifos and thiamethoxam.