Analysis: Research on the efficient and high-yield cultivation technology of loquat "Guifei".
Xu Qizhi and others
Funds: Basic Scientific Research Project of Fujian Provincial Public Welfare Research Institutes (2020R1028006); National Key R&D Program of China(2019YFD1000905); Funded by the Science and Technology Innovation Team of Fujian Academy of Agricultural Sciences (CXTD2021004-1).
Loquat is a characteristic evergreen fruit tree in the southern part of the mainland, its flesh is soft and juicy, sweet and sour, and it is deeply loved by consumers. With the improvement of people's consumption level, the requirements for the flavor quality of loquat fresh fruit are getting higher and higher, and the original cultivation method of pursuing large fruit and perfect appearance is no longer suitable for the current market development needs, and it is urgent to optimize and upgrade the variety structure to enhance market competitiveness.
Fujian is one of the main producing areas of loquat, with a planting area of 34,300 hm2 and an output of 193,000 tons, but the production of red meat varieties such as Jiefang Zhong and Zaozhong No. 6 accounts for more than 90%, and the flavor quality of fresh fruits is seriously homogeneous, the selling price is low, and the benefits are poor. In the face of the problems existing in the loquat industry, varieties can be improved through high grafting and other methods to promote the adjustment of variety structure, quality improvement and sustainable development of loquat industry.
White meat loquat is a unique loquat germplasm resource in the mainland, is the best in loquat, has the reputation of "uncrowned king", its meat is delicate, sweet, rich and unique, and is favored by the majority of consumers. "Guifei" loquat is a new variety of high-quality large-fruited white-fleshed loquat selected by the Institute of Pomology of Fujian Academy of Agricultural Sciences in 1999 from the actual population, showing excellent traits such as high quality of large fruit, early fruiting and high yield, strong stress resistance and good storage performance. On June 30, 2014, it was approved by the National Committee for the Examination and Approval of Tropical Crop Varieties.
This variety can not only promote the upgrading of loquat and new varieties, but also promote the sustainable development of loquat and the industry. In recent years, in order to give full play to the advantages of this variety, the introduction test demonstration has been carried out in Fujian, Sichuan, Chongqing, Guangdong and other places, and good results have been obtained.
1. Overview of the demonstration base
Putian Honggeng Agricultural Development Co., Ltd. Loquat Ecological Demonstration Park is located in Duli Village, Changtai Town, Chengxiang District, Putian, Fujian Province, with an altitude of about 200 m and a slope to the southeast. In 1999, Zaozhong No. 6 loquat was planted, with a planting area of about 10hm2. In 2014, the orchard was renovated to realize the "four links" of the orchard, namely road communication, water communication, electricity communication and network communication. Roads, one 100m3 reservoir, two 30m3 water distribution pools and water and fertilizer integration facilities have been built in the park, and the whole park has been electrified, as well as other ancillary facilities such as management rooms, cold storage, and Internet of Things monitoring. According to the slope, topography, topography, and planting direction, repair the field terraces, build a horizontal terrace of about 4m, and the terraced table surface should have a stalk in front and a ditch in the back. In 2016, the "Guifei" loquat was high, with an area of 4hm2, a plant row spacing of 5m×5m, and an average of 26 plants/667m2. At the same time, the hole was expanded, the soil was fertilized, and the tree was restored.
2. Fertilizer and water management
According to the phenological period, fertilizer needs and fruit development of the concubine, the appropriate fertilization period was determined. Adult fruiting trees are generally fertilized 3~4 times a year. From February to March, strong fruit fertilizer was applied, and medium and trace element formula water-soluble fertilizer was applied to promote fruit expansion; from May to June, fertilizer was applied after fruit picking and orchard clearing, mainly organic fertilizer, and 20~25kg of rotted organic fertilizer such as chicken manure + 2kg of glycanase phosphate fertilizer were applied to the plant to promote the recovery of tree potential and extract strong fruiting mother branches. In October, strong flower fertilizer was applied, and a large number of elements were applied to formulate water-soluble fertilizer to provide nutrients for the development of flower buds. The formula of water-soluble fertilizer is: 30t water + 1t peanut bran fermented bacterial fertilizer + 25kg of balanced compound fertilizer (N:P:K ratio 17:17:17) + 20kg of macroelements (potassium sulfate) or 40kg of medium and trace elements (calcium, magnesium, iron, zinc) water-soluble fertilizer + 20kg of mineral-derived humic acid or amino acid water-soluble fertilizer (Bet).
3. Grass cultivation
In order to maintain the ecological balance of the orchard, reduce the occurrence of pests and diseases, and prevent soil erosion in the orchard, the orchard mainly sowed the 1-year-old herbaceous plant Huoxiang thistle species, as well as interplanting green manure such as Pinto peanut, Huoxiang herb, and Cassia feather, and timely cleaned up the harmful weeds such as wild kudzu, white grass, and flanny tillers, so as to effectively promote the growth of green manure. Through grass cultivation, a benign grass community in the orchard is formed, which prevents soil erosion in the orchard, protects the ecological environment, increases the organic matter fertilizer of the soil, and fertilizes the soil. Grass cultivation also increases the biodiversity of orchards, provides a good living environment for natural enemies of pests, and plays an important role in the comprehensive prevention and control of loquat diseases and pests.
4. Tree management
4.1 Juvenile tree management
Grafting began in 1-2 months. During grafting, 3~8 backbone branches with uniform distribution and 50~100cm above the ground are selected as the grafting site according to the tree shape, and the low-level multi-head high-grafting is carried out. After grafting, topping is carried out when the branch tips grow to 20~30cm, the growth of the central branch is controlled, the secondary secondary main branch is promoted, and 2~3 branches are extracted on each secondary main branch to form a third-level backbone branch, and then the fruiting branch group is cultivated on the backbone branch. At the same time, the thin fertilizer was applied frequently, and a mixture of 0.3% urea and 0.3% potassium dihydrogen phosphate was sprayed for extra-root topdressing before the new shoots were extracted to promote the growth of new shoots. In the second year of grafting, branches were pulled and hung, and the branches were pulled to expand outward, and the multi-main branches were cultivated with high light efficiency wave tree shape. After 3 years of tree cultivation, the number of branches of the tree reaches 6~7 levels, forming a high-yield and fruiting tree.
4.2 Result tree management
The main requirements of the adult fruiting tree of loquat are to keep the fruiting part below 2.5m and the crown height to be controlled below 3.0m.
The management of branch tips should be pruned in time after fruit picking with Xu Qizhi and other methods, and the fruiting branches of the current year should be shortened and retracted; the second pruning should be carried out in combination with thinning flowers during the flowering period, and the branches that have not become flowers and the growth of thick lateral branches should be 1~2 branches; at the same time, too many side branches, diseased branches, and overly dense branches should be pruned. After stub pruning, the excess new shoots and lateral branches should be erased in time, and the thick fruiting mother branches should be cultivated. When the height of the fruiting tree exceeds 3.0m, the main trunk can be retracted and pruned appropriately, and the growth of new shoots can be controlled at the same time, and the height of the tree can be controlled within the appropriate range.
5. Flower and fruit management
Flowers are thinned in mid-November. First thin the flower spikes, thin the flower spikes that bloom too early and late, try to retain the flower spikes with a more consistent flowering period, and the amount of flower spikes retained accounts for about 50% of the total number of branches of the whole tree, and then thin the buds left behind, and retain 3~4 strong branch spikes in the middle of the outer side of the flower spikes, so that the structure of the spikes is reasonable, the flowering period is concentrated, and it is convenient for bagging. After flowering in December, spray 1 fungicide thiophanate-methyl (1500 times solution) + thiamethone (1500 times solution) + brassinin (2000 times solution) to control pests and diseases. Fruit thinning begins in January. First, remove diseased and insect fruits and deformed fruits, and then remove too large and too small fruits, leaving 5~8 young fruits with uniform distribution and consistent size, so that the fruit maturity period of each spike is basically the same, which is conducive to concentrated fruit picking. Bagging is carried out after fruit thinning. First, cover the fruit with a foam net bag, and then put 3~5 leaves and fruits into a kraft paper bag to prevent bird damage, sunburn, fruit cracking and mechanical injury.
6. Pest control
According to the occurrence law of pests and diseases, physical and biological control should be reasonably applied to achieve effective control of pests and diseases. After picking fruits, the whole orchard is cleared, the paper bags in the orchard are centrally treated, and the dead branches and leaves under the trees are cleaned up in time to reduce the epiphysis of insect eggs and reduce the occurrence of pests and diseases. Spray fungicide thiophanate-methyl (1800 times solution) + cypermethrin (1800 times solution) + brassinin (2000 times solution) during the growth process of summer shoots; spray fungicide thiophanate-methyl (1500 times solution) + thiamyzone (1500 times solution) + brassinin (2000 times solution) after flowering from November to December; hang yellow boards in the whole garden in March to physically trap and kill leafhoppers, moth adults and other pests, and hang orange small fly trapping devices at the same time to prevent adults from harming fruits.
7. Demonstration results
In the second year of grafting, the crown could reach 2.28m×2.36m, the tree height was 2.33m, some flowers and fruits, the number of flower spikes was 33.1, and the branch tip heading rate was 35.1%, and the crown could be restored to 3.02m×3.1m, the tree height was 2.86m, the number of flower spikes was 103.0, and the branch tip heading rate was 66.5%, and the yield was basically restored. After years of implementation and integration of loquat variety update, high-yield and high-efficiency cultivation technology system, in April 2022 passed the on-site acceptance of relevant experts, "Guifei" loquat 6-year-old tall tree, the average plant yield of 42.57kg, the commercial fruit rate of 87.84%, the average yield of 990.54kg/667m3, the average fruit weight of 69.01g, the edible rate of 74.07%, and the soluble solid content of 12.75%. The demonstration base integrates technologies such as rapid renewal of loquat varieties, high light efficiency tree shape and strong fruiting mother branch cultivation, and integrated management of water and fertilizer, which effectively reduce labor costs, reduce the amount of pesticides and fertilizers, and achieve the cultivation goal of improving quality and efficiency.