How to popularize conventional comprehensive supporting technologies and new technologies, and study the standardized cultivation techniques for high and stable yield of main tree species with high quality as the center? 1. Dwarf and close planting

It is one of the development trends of fruit tree production from thinning to dwarfing and close planting. In recent years, the technology of dwarf and dense planting of fruit trees has been extended from citrus to traditional sparse planting fruit trees such as litchi and longan, which has become a technical component of intensive cultivation. Dwarf close planting changes the nutrient distribution of trees, and concentrates more nutrients on fruit formation, which can improve land utilization, facilitate management, save labor, save pest control costs, improve harvesting efficiency, increase early yield per unit area, and recover orchard investment as soon as possible. At present, the close planting of fruit trees in tropical areas is mainly carried out by pruning, girdling, cutting and other techniques, but the research on the main methods of close planting, the application of dwarf rootstocks and dwarfing culture varieties, and the mechanism of dwarf is almost blank, and the use of chemical inhibitors, planting density, methods, corresponding supporting technologies, yield and input-output benefits need further study.

2. Orchard soil, irrigation and water conservation

Soil is the foundation of fruit tree growth. It is advocated to improve the soil before planting trees, or to expand holes in stages after planting trees, focusing on improving the middle and lower soil of 20 ~ 60 cm. In the soil with strong acidity, we should pay attention to the adjustment of pH value. The effect of water on the growth and yield increase of fruit trees is obvious. 70% of citrus orchards in the United States, 87% of apple orchards in France and 94% of pear orchards have irrigation facilities. According to the water demand characteristics, climate, soil, water source conditions and investment of various fruit trees, appropriate water supply methods should be adopted to supply or control the water of fruit trees in time. Adequate water is beneficial to vegetative growth, and water supply during cell division and cell expansion is the basis for increasing fruit, while water control at maturity is beneficial to improving sugar content and storage resistance of fruit. It is necessary to maintain the balanced supply of water through the management system of "covering soil moisture according to phenological needs, combining reasonable water supply with intertillage". High ridge plastic film mulching cultivation is a soil management system to improve fruit quality, which can be tried in some areas with rainy and high groundwater level.

3. Balanced fertilization of fruit trees

It is a reasonable fertilization technique to guide the balanced fertilization of fruit trees according to the nutritional diagnosis results of fruit trees. There is not much research on fruit trees in tropical areas in China. Because of unreasonable fertilization and unbalanced nutrition of trees, plant growth and fruit quality are affected to varying degrees. It even causes obvious physiological diseases, reduces the resistance to pathogenic bacteria and shortens the storage life after harvest.

The nutritional diagnosis of fruit trees can not only diagnose the symptoms of deficiency or excessive harm of various nutrient elements, but also find the potential nutritional imbalance that has no obvious symptoms but has affected the yield and quality of fruit trees, and make or revise the fertilization plan accordingly.

In particular, element deficiency, a fruit tree in tropical areas of China, is particularly deficient in calcium, and many physiological diseases are related to it.

Focusing on improving quality, the research on fertilization technology reform was carried out from the aspects of nutrient element ratio, fertilization period, dosage ratio in each period and fertilization method. It is necessary to control the application of pure chemical fertilizers, especially nitrogen fertilizers, and pay attention to the application of organic fertilizers, phosphorus and potassium fertilizers, compound fertilizers and other full fertilizers.

4. Resistant cultivation and integrated pest control

The frequency of low temperature freezing injury in tropical fruit areas is high in winter and spring, and typhoons occur frequently in some places. In addition to carefully selecting the garden site to avoid cold and wind, planting in suitable places and building shelter belts, a series of targeted comprehensive technologies should be adopted to cultivate resistance according to the main local disasters, and timely rescue measures should be taken after the disaster. Some tree species are difficult to grow in warm winter, so it is necessary to choose varieties with low cold demand in winter, take measures to promote flowers and fruits, and study ways to overcome them. The problem of environmental pollution is becoming more and more common. Brick factory, ceramic factory, cement factory, glass factory, anodic alumina factory, etc. A large amount of SO2 and fluoride is discharged, which poisons the surrounding fruit trees and harms the growth results. It is necessary to strengthen monitoring. New factories should take into account the needs of agricultural development and minimize the impact. Fruit tree bases should be avoided in pollution source areas, and effective measures to control air pollution should be studied.

In hot areas with high temperature and high humidity, pests and diseases breed rapidly and seriously, and many fruit diseases have seriously affected the quality, storage and transportation life, and even lost the harvest. It is necessary to study the epidemic law of various pests and diseases, adopt agricultural, biological and chemical agents for comprehensive prevention and control, establish a network for forecasting pests and diseases, strengthen information exchange, and guide prevention and control in time. The indiscriminate application of pesticides and spraying of insurance drugs is serious. It is necessary to strictly control, strengthen guidance, protect natural enemies, and advocate biological control and comprehensive control.

5. Improve the plastic trimming technology.

Plastic pruning plays a great role in cultivating good fruit load structure, improving ventilation and light transmission conditions of crown, adjusting the balance between vegetative growth and reproductive growth, reducing the occurrence of diseases and pests, overcoming fruits in different years and improving fruit quality. Except citrus, most evergreen fruit trees are neglected to prune, which is generally limited to low-level thinning diseases, insects and weak branches. It is necessary to study the high-yield tree structure of various evergreen fruit trees, the influence of pruning on the growth and fruiting of branches, the intensity and method of pruning period, and cultivate high-yield trees through reasonable pruning, improve the quality and overcome the age.

6. Rational application of plant growth regulators

Growth regulators can often solve some problems that cannot be solved by general technical measures. In tropical and subtropical fruit trees, plant growth regulators can promote root cutting, control growth, promote flowering, regulate flowering period, sparse flowers, preserve fruit, promote fruit growth, accelerate ripening, improve quality, improve commodity rate and prolong fruit storage period. However, its application effect is often influenced by many factors inside and outside the fruit tree. To avoid abuse, combined with the development mechanism and external environment of fruit trees, the applicable conditions and application technology of each drug should be studied.

7. Break traditional habits and reform training methods.

In spring, the frequency of low temperature and rainy weather in flowering period increases. After keeping flowers and fruits, the quality of fruits is often reduced because of too many fruits. In order to overcome the old idea of one-sided flower protection and fruit protection, timely thinning ears and fruits in batches and adjusting tree load are necessary measures to improve fruit quality and commodity and overcome the phenomenon of big and small years. At the same time, manually adjust the number of fruits; The use of chemical flower thinning and fruit thinning agents should be studied.

At present, the phenomenon of early harvest is quite common, and advocating "full-ripe cultivation", that is, combining with corresponding technical measures, harvesting in batches at the right time when the fruit appearance and internal quality reach the best state, is one of the measures to greatly improve the fruit quality.

Protected cultivation is an important measure to improve the quality and commodity of fruits and prolong the supply period of fresh fruits in Japan. Hami melon was successfully cultivated in Guangdong greenhouse; The technology of "high grafting pear" in Taiwan Province Province makes the production mode of temperate pear in south subtropical zone worth learning.

We should attach importance to the introduction of new technologies, reform traditional cultivation methods, and do everything possible to improve fruit benefits.