Planting techniques of "improved Chunjie" Daya Citrus

Daya citrus was bred by the cross between Qingjian Orange and New Line No. 3 Ponkan in China Citrus Research Institute. The fruit appearance and tree body are very similar to those of Spring Citrus, but its quality is better than that of Spring Citrus, so some people call it "improved Spring see". So, what are the planting techniques of Daya mandarin?

First, the basic introduction of Daya mandarin

1. Variety characteristics

Tree characteristics: the tree is strong, the ability to shoot is strong, and the crown is formed quickly; the shape of the tree is upright in front of the fruit, and opens gradually after the fruit, and the crown is round head shape. The leaf is light green, acuminate, the leaf margin is shallowly serrated, there are many grooves at the top, and the wing leaves are nearly linear; some spring shoot leaves are twisted and rolled inward; the flowers are larger and the vitality of living powder is high.

Phenological period: sprouting from late February to early March, spring shoot growth and leaf expansion from late March to early April, flowering in mid-late April, summer shoot budding in mid-May and June, fruit expansion in late June, autumn shoot budding in mid-late July, fruit beginning to change color in mid-late October, ripening from late January to mid-February in the following year, and leaving trees until April at the latest.

Fruiting habits: spring and early autumn shoots were used as fruiting mother branches, and most of the fruiting branches were leafy and flowering branches, and the fruit setting rate was high.

Fruit character: the mature fruit is orange-yellow, the oil cell is fine, smooth, shiny, the pericarp is thin and easy to peel. The fruit is large and generally seedless. Under the condition of mixed planting, there are occasionally a small number of seeds, multi-embryo and good comprehensive quality.

2. Main advantages

High fruit setting rate, high early fruit yield, Spring Festival listing, high yield, high sugar, delicate meat and excellent quality.

3. Some deficiencies

The pericarp is thin, hanging trees in winter are vulnerable to low temperature freezing damage, the need for bagging delayed harvest, high production cost, not resistant to storage and transportation, high loss.

2. Planting techniques of Daya mandarin

1. Rootstock selection

Rootstocks such as Fructus Aurantii and tangerine can be selected for planting in acidic soil, but strong rootstocks such as orange are recommended for planting in weakly alkaline soil.

High grafting replacement is considered in tangerine, mandarin, golden orange, navel orange and other trees, put into production more quickly.

2. Fertilizer and water management

Daya mandarin has strong shoot-setting ability, high fruit setting rate, good high yield, long fruit hanging time and large nutritional demand, so it is necessary to ensure the supply of water and fertilizer to ensure strong tree body, high and stable yield.

Young trees: follow the principle of frequent application and thin application, giving priority to root application and leaf fertilizer as supplement. After planting, we can start topdressing with fixed root water after one month, apply sea elves biological stimulant (root application type) + available nitrogen fertilizer twice a month, and re-apply organic fertilizer combined with hole expansion and soil improvement in late October.

Hanging fruit trees: apply pre-flowering fertilizer before spring shoot germination, mainly nitrogen fertilizer combined with sea elves biological stimulant (root application type); due to the high fruit setting rate of Daya mandarin, stable fruit fertilizer can be applied less or not; strong fruit fertilizer can be re-applied, organic fertilizer + balanced or high potassium compound fertilizer + medium trace element fertilizer; after October, the tree potential can be increased by a pre-harvest fertilizer, mainly phosphorus, potash, organic fertilizer, supplemented by a small amount of nitrogen fertilizer, in order to keep the tree fresh.

3. Trim and reshape

Basic principles: to create a compact, full and solid crown skeleton; conducive to the full use of light to achieve the balance between vegetative growth and reproductive growth; conducive to three-dimensional results; conducive to early production and high and stable yield.

The branches of Daya mandarin are upright, and their branches and branches are very strong. when shaping and pruning young trees, we should pay attention to open tree shape, sparse and short, so as to improve the quality of branches and increase ventilation and light transmission.

Results the spring and autumn shoots were mainly thinned, the closed branches which affected the light were thinned, the erect strong branches and overgrown branches were cut off, so as to avoid the influence of excessive branches on the fruit of the next year and leave more mediocre branches. Summer shoots and late autumn shoots are mainly controlled.

4. Flower and fruit management

Due to the high fruit setting rate of Daya mandarin, it will end up in clusters without any flower protection medicine. when fruit preservation agents such as gibberellin and cytokinin are used to protect fruit, it is easy to cause floating skin and decline in quality. therefore, the sea elves biological stimulant (leaf type) can be sprayed in the young fruit stage.

The high yield of Daya mandarin will not only affect the quality, but also lead to the weakening of trees, yellow trees and even dead trees. Attention should be paid to thinning flowers and fruits, hanging fruits in an appropriate amount, reducing the occurrence of large and small years, and ensuring the quality of fruits.

Because of the thin pericarp, the fruit hanging trees are easy to be damaged by low temperature in winter. Bagging technology should be implemented in the middle of October, and plastic film should be covered in time to prevent cold and freezing in winter.

The suitable harvest time is from late January to mid-late March in the following year to avoid hanging trees for too long to affect the quality and tree potential.

5. Pest control

The main diseases are anthracnose, scab, fat spot yellow spot, Huanglong disease, and the main pests are red spider, rust wall lice, leaf miner, leaf beetle, aphid and so on. Comprehensive control should be carried out by strengthening cultivation management, strengthening tree potential, using drugs scientifically, and paying attention to the protection of natural enemies.