Cultivation Points for the Extremely Late-Maturing Peach Strain Dongxuewang

Dongxuewang (tentative name) is a new strain bred by the Yimin Fruit Tree Research Institute of Qingzhou City, Shandong Province, using Dongxue Honey Peach as the female parent and Zhonghua Shoutao as the male parent. It was crossed in 1998, seedlings were raised in 1999, top-grafted in 2000, fruited in 2001, and multi-point trials were conducted in 2004. The strain characteristics and cultivation points are described below.

1 Characteristics

1.1 Botanical characteristics The Dongxuewang peach tree has a relatively open growth habit, 1-year-old mature branches are reddish-brown, and the main branches and perennial branches are grayish-white. Leaves are dark green, large, 13.82 cm long, 3.16 cm wide, with a hundred-leaf weight of 56.29, a hundred-leaf thickness of 3.13 cm, and a petiole length of 1.8 cm; nectaries are kidney-shaped and extremely small. Petals are pink, half-open, with abundant pollen.

1.2 Fruit economic traits The Dongxuewang peach fruit is round, with a longitudinal diameter of 6.6 cm and a transverse diameter of 6.9 cm, and the fruit shape is well-formed. The fruit is large, with an average single fruit weight of 215.6 g and a maximum fruit weight of 400 g. The ground color is yellow-green, and the surface has patches of bright rose red. The fruit apex is flat, and the fruit tip is slightly protruding, similar to Zhonghua Shoutao. The fruit surface is smooth with few hairs, the stem cavity is shallow, and there is no fruit russeting. The skin is thick and smooth. The flesh is milky white, pink near the pit, and milky white near the skin; the texture is firm and crisp, the soluble solids content is 18.1%, the flavor is sweet and aromatic, and the quality is excellent; the pit is small, weighing 6.5 g, and the edible rate of the fruit is 97%. Clingstone to semi-freestone, the fruit has high firmness and is storage-resistant; at room temperature it can be stored until New Year's Day, and in cold storage it can be kept until the Spring Festival.

1.3 Growth and fruiting habits Young Dongxuewang peach trees are vigorous, upright, stop growing late, and have a large annual growth amount; after fruiting, the tree vigor is moderate and the canopy is open. Current-year branches grow vigorously and have a habit of multiple growth flushes. The tree mainly bears fruit on medium and long fruiting branches, and after the tree vigor becomes moderate, it bears fruit on medium and short fruiting branches. Self-pollination ability is strong, and no pollinizer is needed. It has strong early fruiting and high-yield potential; in high-yield orchards, the yield per 667 sq m is more than 4000 kg.

Fruit development is clearly divided into three stages: from after petal fall to early June is the rapid fruit growth stage, when the fruit grows quickly and longitudinal development exceeds transverse development; in mid-June the fruit enters the slow growth stage, with very little fruit enlargement, dark green color, and abundant hairs; only in mid-September does the fruit enter the rapid expansion stage, when it expands quickly, hairs decrease, coloration begins, sugar content increases, and the characteristics proper to this variety are displayed; in late October it enters the harvest period.

1.4 Phenological period In ordinary years, buds sprout in mid-March, flowering occurs in early April, and the flowering period is about 10 days. The fruit development period is about 200 days, and it matures and is harvested in late October. The new shoot growth period is from early April to early September, with a habit of multiple growth flushes. The leaves have strong cold resistance, and defoliation does not begin until the temperature drops below 0°C in mid- to late November.

1.5 Adaptability and stress resistance This strain has strong adaptability and features drought resistance, cold resistance, few insects, and strong disease resistance. In mountainous and hilly areas without irrigation conditions, growth and fruiting are normal. Its cold resistance is especially strong; in ordinary years, it begins to shed leaves only 1 month after other peach varieties have shed theirs, and no winter freeze damage has been seen in Qingzhou. From June to August, the season when pests and diseases occur frequently, this peach is in its slow growth stage, the fruit is small, and there are many hairs, so fruit-feeding pests rarely lay eggs on Dongxuewang peach, and therefore the rate of insect-damaged fruit is very low. Under normal management, the insect-damaged fruit rate is about 1%, only 1/10 that of other varieties. There are also relatively few diseases.

2 Cultivation points

2.1 Orchard establishment Dongxuewang peach likes light and tolerates drought and barren soil, so an orchard can be established on hilly land with a soil layer 20-30 cm thick. It can also be established on flat land, beach land, and sandy loam plots with a groundwater level below 1 m, good drainage, no water accumulation in the rainy season, no waterlogging, and good aeration. Planting is generally done before sprouting in spring; the self-pollination rate is high, and no pollinizer is needed. On hilly land, a suitable spacing is 3 m x 4 m or 3 m x 4.5 m; on flat land, 3 m x 5 m or 4 m x 5 m.

2.2 Fertilizer and water management Topdress 3 times before sprouting, after fruit set, and during the rapid fruit expansion stage, especially the fruit-promoting fertilizer in mid-September (that is, the rapid fruit expansion stage), which is particularly important. In the early stage, mainly nitrogen fertilizer is used; in the later stage, a nitrogen-phosphorus-potassium compound fertilizer is applied, generally 0.5-1 kg per tree. After early May, every 10-15 days, combined with pesticide spraying, spray the leaves with 0.3%-0.5% urea plus 0.3% potassium dihydrogen phosphate, or spray 200-fold photosynthetic microfertilizer. Throughout the year, irrigate 3-4 times in combination with topdressing before sprouting, after fruit set, during the expansion stage, and with the winter freezing water. In the rainy season, drain promptly to prevent waterlogging.

2.3 Training and pruning Dongxuewang peach is suitable for the natural open-center form, with the trunk generally about 50 cm and the basal angle of the main branches 45-55°. In the first 3 years after planting, winter pruning of the main branches should be light rather than heavy, so as to increase the number of branches as quickly as possible and bear fruit earlier. Each year, use long and medium fruiting branches on the main branches to develop small fruiting branch groups or several single fruiting branches. On the upper side of the main branches, fruiting branch groups should be small rather than large; on the two sides and underside, large and medium fruiting branch groups can be retained, and attention should be paid to timely renewal of fruiting branch groups. Summer pruning should be carried out 2-3 times each year, removing water sprouts and heading back vegetative branches to speed up the development of branch groups.

2.4 Pest and disease control Before sprouting, spray the trunk and branches with 5 degrees Baume lime sulfur mixture to control various pests and diseases. During the growing season, spray 1500-fold Yashijing to control aphids; about 20 days after petal fall, spray once with 2000-fold Nisuolang or 3000-fold Mansijing to control spider mites; in mid-June, mid-July, and mid-August, spray once each time with 2000-fold 25% Mieyouniao No. 3 to control leafminer moths. In late May and late June, spray 2000-fold Taoxiaoling to control peach fruit borer and peach fruit moth. Beginning in late April, use 1000-fold 50% carbendazim liquid and 500-fold 50% mancozeb liquid, alternating once every half month, to control gummosis and bacterial shot hole disease.