Tree feature
Daya Citrus was bred by crossing Qingjian Orange × Xinshengxian No.3 Ponkan in China Citrus Research Institute. The fruit appearance and tree body are similar to those of Chunjian, but the quality is better than Chunjian, so some people call it "improved Chunjian". The fruit is large, weighing 290g, oval, orange peel, easy to peel, tender pulp, juicy, soluble solids 15.5%, acid 0.8%. After full maturity, the soluble solids can reach 19% ~ 22%, the edible rate is 7 1%, and there is no seed. The leaves are dense, dark green, broadly lanceolate, pointed and tapered, with wedge-shaped base, entire leaf margin and linear wings. The leaf is about 8.4 cm long and 3.5 cm wide, with a leaf shape index of 2.4. The flower is small, with five white petals, the petals are 1.02 cm long and 0.45 cm wide, the style is tall and upright, the stamens 17 ~ 20, the anthers are light yellow and the pollen vitality is high. The average weight of a single fruit is 290 grams, with a transverse diameter of 7.6 cm and a longitudinal diameter of 7.4 cm. Mature fruit is yellow, smooth and shiny, with fine oil cells, thin peel, 2.2-4.0 mm thick, easy to peel and seedless. Soluble solids reached 16%, total acid was 0.35g/ 100ml juice, and Vc content was 32m g/ 100ml juice. The pulp is crisp and tender, with rich flavor, good taste, rich aroma and excellent quality. The soluble solid content reached more than 12% in early February of that year, and the titratable acid content reached less than 1.0 in late October of the following year, which reached the commodity harvesting conditions. In early February, the soluble solids reached more than 16%, and then the titratable acid content gradually decreased to about 0.5 in mid-March. Excellent quality, in line with the requirements of high-quality goods harvesting and marketing, fresh fruit harvesting and marketing period can be as long as 3 months. It is possible to develop citrus producing areas where the average annual temperature in the mid-subtropical zone is 16.5 degrees and the lowest temperature in winter is not lower than-1 degree.
Yield performance
This variety mainly uses early autumn branches as fruiting mother branches, and the fruiting branches are mostly leafy flowers. Generally, the fruit setting rate in the middle and lower part of the crown is high. After three years of planting, the grafted seedlings of Poncirus trifoliata "Daya Za" began to try flowers, and the plant yield could reach 5. 1 kg in the fourth year and 19.7 kg in the fifth year. In the second year, a small amount of "Dayan Saigong" was planted on the intermediate stock of Rinan 1, and the yield per plant was between 3.4kg- 10.4kg. In the third year, the yield per plant was 17.2 kg, and the yield per mu was about 1400 kg.
Key points of cultivation
The cold tolerance of Dayan hybrid orange is moderate, and it is suitable for planting in citrus producing areas with annual average temperature above 17.5℃, and the lowest temperature in winter is not lower than -7℃. In production, orange, red orange, bitter orange and orange can be used as rootstocks, which have graft incompatibility with pomelo, so avoid choosing pomelo as rootstocks. In high-calorie areas, strong roots such as Volka Mo and coarse lemon should be avoided to avoid the flavor fading due to low acidity of fruits. The main characteristics of grafting of Fructus Aurantii are fast growth and high yield, and the characteristics of Fructus Aurantii are good taste and strong drought resistance. Dayan hybrid orange grows vigorously, has a long fruit-bearing time and needs a lot of fertilizer and water. In production, base fertilizer should be applied again, and the base fertilizer is mainly decomposed and fermented farmyard manure and compound fertilizer. When planting in purple soil and barren sloping land, it is necessary to strengthen soil improvement, apply more organic fertilizers and phosphorus and potassium fertilizers, and supplement zinc and magnesium fertilizers appropriately to ensure the dark green leaves.