Apple cultivation has its particularities: these 5 major environmental requirements are all indispensable
Apples are one of the common fruits in our daily lives, with a wide planting range and many growers. However, quite a few apple growers have misconceptions during apple production; not all places are suitable for growing apples, which leads to apple yields and quality that cannot improve. Agricultural technical experts say that for apples to grow healthily, the following 5 major environmental requirements must be met!
1. Temperature requirements
The temperatures in Shandong, Hebei, Shanxi and Shaanxi are suitable for apple cultivation. Winter low temperatures generally do not cause freezing damage to apple trees, but in orchards where apples grow vigorously in autumn, there can be shoot shriveling and flower freezing in winter; when the tree is weakened, severe winter cold can worsen rot disease the following year. In orchards where flower buds are prone to freezing damage in winter, pruning should be delayed until spring. In Henan, Shandong and the southern parts of Hebei Province, the average annual temperature is relatively high and the growing season is longer, so shoots grow abundantly and there can be excessive vigor without timely flower formation and fruiting. When planting, the plant and row spacing should be larger, and pruning should moderately control excessive vigor.
2. Precipitation requirements
According to the needs of apples, an annual rainfall of 500-600 mm is enough to ensure normal growth and fruiting of apple trees. However, under conditions in North China, the monthly distribution of rainfall is uneven, with frequent spring and autumn droughts, so irrigation must be considered. High-yield orchards are all orchards with irrigation conditions. The experience accumulated in various places is that irrigation before flowering, during the rapid shoot growth period, during the rapid autumn fruit growth period and during the post-harvest recovery period, plus drainage in summer, are the keys to high yield.
3. Light requirements
Among fruit trees, apples are a species with moderate light demand; only with sufficient light can normal growth and fruiting of apples be ensured. The sunshine hours in various parts of North China can meet the needs of apple growth and development. In densely planted orchards, because the amount of branches and leaves is too large and the trees shade each other, there is also the problem of insufficient light. One of the functions of training and pruning is to enable all parts of the canopy to obtain good light conditions. In particular, the light conditions of densely planted orchards, closed-canopy orchards, orchards on shady slopes and the inner canopy of trees should be improved to ensure sufficient light. Therefore, some surveys and studies suggest that the light intensity in the middle and lower parts of the canopy should preferably be no less than 20-30% of natural light intensity.
4. Wind requirements
Wind has both advantages and disadvantages for apple trees. A gentle breeze of force 2-3 is beneficial to air circulation in the orchard, enhances photosynthesis and reduces disease occurrence; it is also beneficial to the activity of beneficial insects and improves pollination effectiveness. But strong winds can blow down fruit and cause the canopy to lean and not spread open. When pruning, in leaving buds and opening the angles of branches, attention should be paid to wind direction.
5. Soil requirements
Apple trees need a certain soil depth, good drainage, rich organic matter, and slightly acidic to neutral soil. Clay soil has poor aeration; if there is a layer of hardpan below the topsoil, if the soil layer in mountainous areas is less than 60 cm deep, if riverbank land has thick gravel layers, or in heavily saline-alkali land, in addition to poor availability of the major elements nitrogen, phosphorus and potassium and poor water supply conditions, deficiency symptoms of the trace elements iron, boron and zinc are also likely to occur, causing poor development of the fruit trees. Under such soil conditions, one cannot rely on training and pruning to change the growth and development status of apple trees. It is necessary to plant according to site suitability and to deep plow, apply soil, apply sand and increase organic fertilizer to improve the soil, so that apple trees can grow and develop well and training and pruning can play their role.