Is Lancang County, Pu 'er City, Yunnan Province Suitable for Planting Kiwifruit?

First, the requirements of kiwifruit growth environment

According to the investigation of local resources and the practice of introduction and cultivation, it is proved that the main ecological factors affecting the growth and development of kiwifruit are temperature, humidity, soil and light.

1. temperature: temperature crossing is one of the important factors affecting the growth and development of kiwifruit. Temperature not only affects its geographical distribution, but also affects its growth and development process. According to the comprehensive analysis of temperature factors in kiwifruit production, kiwifruit can grow normally in the area with annual average temperature 1 1℃. Annual average temperature11.3-16.9℃, extreme maximum temperature 33.3-4 1. 1℃, extreme minimum temperature -9.6-20℃, and accumulated temperature of 4500-5200 ≥ The germination of kiwifruit is very sensitive to the requirement of temperature, and the average temperature of its germination is relatively stable. According to the determination in different areas at home and abroad, it is considered that the biological zero of kiwifruit is 8℃, and when the daily average temperature is higher than 8℃, Hongyang kiwifruit begins to germinate and grow. If the average temperature is lower than 8℃, the growth of kiwifruit will be affected. Long-term high humidity and dry weather in summer will also affect the growth and development of Hongyang kiwifruit, and there will be deciduous, fruit dropping or dead branches.

2. Soil: Soil is the foundation of kiwifruit growth. The nutrients and water needed by kiwifruit are mainly obtained from soil. The physical and chemical properties of soil directly affect the growth and development of kiwifruit. Kiwifruit likes sandy loam with deep soil layer, fertile and loose soil, good water retention and drainage, and high humus content. This kind of soil has a good aggregate structure, which is conducive to the excellent conditions of water storage, water conservation, fertilizer conservation and fertilizer supply, so it is conducive to the growth and development of roots. Kiwifruit grows well in sandy loam, because this kind of soil can meet the requirements of good ventilation and water permeability of its fleshy roots. Kiwifruit doesn't grow well in cohesive soil because of poor clay aggregate structure, poor ventilation and water permeability, and poor root development. Therefore, we should pay attention to the choice of soil when planting Hongyang kiwifruit. If we plant it on sticky, waterlogged and dry and barren soil, we must seriously improve the soil. Kiwifruit has certain requirements on soil pH, and generally can grow well in acidic, weakly acidic or neutral soil, so it likes the soil to grow normally in the range of PH5.5-6.5. In alkaline soil above PH7.5, kiwifruit will turn yellow due to iron deficiency. If the cultivation techniques can be applied in time to improve the required conditions, good growth effects can also be obtained. Through soil improvement and fertilization, kiwifruit basically grows well.

3. Moisture: Moisture is the most basic component of kiwifruit, and it must participate in various life activities. Insufficient or excessive water will affect the growth and development of kiwifruit. Kiwifruit has shallow roots, fleshy roots, few trunk roots, underdeveloped lateral roots, vigorous branches and leaves on the ground, thin and large leaves, thin cuticle, thick xylem vessels in roots and stems and large water evaporation. These characteristics determine that kiwifruit is a tree species with weak physiological drought tolerance and strict requirements on soil moisture and air humidity. In particular, it is necessary to shade properly and keep the soil moist frequently to avoid seedlings dying. Kiwifruit on sunny slopes is dry and barren on ridges and hilltops, and often does not grow well. In the case of drought and high temperature, kiwifruit shows small leaves, yellow flowers, slow or stopped growth of new shoots, withered leaves or fallen leaves, and a large number of fallen leaves and fruit drop, which can lead to the death of the whole plant in severe cases. In the growing season, high temperature and drought are two main factors that endanger the growth and development of wild plants. Drought resistance is the main agricultural measure to prevent high temperature and drought. Through timely and reasonable irrigation, the temperature can be indirectly reduced and the harm of high temperature can be alleviated. Because plants transpiration a lot of water, the temperature of trees will also decrease. Kiwifruit grows well in the environment of annual rainfall 1000mm and air relative humidity of 70%-80%.

4. Illumination: Kiwi's demand for light varies with age. They like shade at seedling stage and light at adult stage. Under good lighting conditions, trees are robust, with few or no flowers and fruits. If there is too much shade, the branches will not grow enough, the lower branches will die easily, the fruit will be small or not, and the quality will be poor. Kiwifruit should not be exposed to strong light. Direct strong light accompanied by high temperature and drought is extremely unfavorable to the growth of kiwifruit, which often leads to serious sunburn or even a large number of fruit drops, affecting yield and quality. The sunshine hours in the natural distribution areas of kiwifruit are mostly between 300 and 2600 hours, which can generally meet the requirements of light during its growth and development.

5. Wind: Wind is one of the factors that affect the growth of kiwifruit. In spring, the new shoots are tender, the leaves are thin and big, and they are vulnerable to wind damage, which makes the new shoots break and the new leaves tear. Dry and hot winds often appear before and after the wheat harvest in May. At this time, the soil moisture is insufficient, and the large hot air flow greatly increases the evaporation. Without protective facilities and insufficient water supply, the leaves begin to turn yellow and brown, and in severe cases, the whole leaves will fall off.

6. Aspect: Aspect has certain influence on kiwifruit. According to the survey, the south slope has strong sunshine, long sunshine time and high temperature. At the beginning of the climate period, the evaporation is large, and it is vulnerable to drought, frost and sun exposure, and the soil is barren. The north slope has low temperature, weak sunshine and short time, high humidity, small evaporation, short climate cycle and fertile soil; The east-west slope is between the north and south slopes. In natural distribution, there are few kiwifruit on the south slope. In addition to the above weaknesses, the natural conditions on sunny slopes also make it difficult for seedlings to survive. Therefore, the natural distribution of kiwifruit is generally in the semi-shady slope, which grows vigorously and bears many fruits. 7. Altitude: Due to the differences in latitude, altitude, climate, landform, soil and social activities, the main distribution areas of kiwifruit are also different in vertical distribution. Generally, the latitude moves northward, and the temperature drops by 0.7℃. Every time the altitude rises 100 meters, the temperature drops by 0.5℃. Therefore, in the northern region, the altitude is too high, the accumulated temperature is insufficient, the growth period is short, the kiwifruit can not mature normally, the quality is poor, and it is vulnerable to freezing injury, thus losing the significance of economic cultivation. The required altitude is between 400- 1000m, and 500-800m is the best. Kiwifruit is distributed everywhere, but it is concentrated at an altitude of 300- 1200m. On the mountain, it is distributed between 500- 1200m and densely distributed between 600-800m. It is relatively dense between 500-750 meters in low mountainous areas. Whether near or far away, kiwifruit rarely grows in inhabited places.