Fertilizer and Water Management Methods and Technical Key Points for Pitaya Orchards

(1) Fertilization

Pitaya, like other cactus plants, has a smaller growth volume than conventional fruit trees. Therefore, fertilization should follow the principle of sufficient amounts, small quantities, and multiple applications. Young trees (1 to 2 years old) should be mainly fertilized with nitrogen fertilizer, applied thinly and frequently, to promote tree growth. Mature trees (3 years old and above) should be mainly fertilized with phosphorus and potassium fertilizers, with the nitrogen fertilizer application rate controlled.

Fertilization should be carried out during the spring new shoot sprouting stage and the fruit swelling stage. The fertilizer is generally formulated with dried cake residue, chicken manure, and pig manure in a ratio of 1:2:7, applying 25 kg of organic fertilizer per plant each year. Alternatively, in July and October each year and in March of the following year, apply 1.2 kg of cow manure compost and 200 g of compound fertilizer per plant each time.

The root system of pitaya is mainly distributed in the topsoil layer, so fertilization should use the broadcast application method. Deep trench application should be avoided to prevent root damage. In addition, after each batch of young fruit forms, spray 0.3% magnesium sulfate, 0.2% borax, and 0.3% potassium dihydrogen phosphate once through the leaves to improve fruit quality.

Because the harvest period of pitaya is long, organic fertilizers should be applied heavily, and nitrogen, phosphorus, and potassium compound fertilizers should be applied in a balanced manner over the long term. If only fertilizers with excessively high nitrogen content such as pig manure and chicken manure are used, the branches will become thicker, dark green, and very brittle, easily broken in strong winds. The resulting fruit will be larger and heavier, with poor quality, low sweetness, and even a sour or salty taste. Therefore, during the flowering and fruiting period, potassium fertilizer, magnesium fertilizer, and bone meal should be added to promote sugar accumulation in the fruit and improve quality.

Pitaya has many aerial roots, which can transform into absorbing roots. By expanding the planting hole and improving the soil, the root distribution can be gradually widened; aerial roots can also be tied and guided down to the ground.

(2) Water Management

Pitaya grows rapidly in a warm, humid environment with sufficient light. During the seedling growth period, the soil throughout the orchard should be kept moist. In spring and summer, water more to keep the root system in a vigorous growth state. During the fruit swelling period, the soil should be kept moist to facilitate fruit growth. When irrigating, never flood-irrigate for long periods, and do not constantly sprinkle water from beginning to end. Flood irrigation will cause the root system to be in a long-term oxygen-deficient state and die, while sprinkling water will cause uneven humidity and induce red spots (a physiological disorder). In continuous rainy weather, drainage should be carried out promptly to avoid infection by pathogens that causes stem and flesh rot. In winter, the orchard should have controlled water to enhance the cold resistance of the branches.