What are the latest apple growing conditions? Read this article to find out
The apple is native to central and southeastern Europe, Central and Western Asia, and Xinjiang, China. It has a cultivation history of more than two thousand years in China, and its main producing areas in China include Baishui, Tianshui, Yantai, Jixian, Yiyuan and other regions. Now let us take a look at what the growing conditions for apples are!
Rainfall requirements
During the growing period, apples need about 180 mm of rainfall per mu of land. Of general natural rainfall, only about 1/3 can actually be used and absorbed by the fruit trees, so a growing-season rainfall of 540 mm is already sufficient. In areas where rainfall from April to September is below 450 mm, irrigation is needed. In northern China, rainfall is unevenly distributed, with 70-80% concentrated in July and August, while water is insufficient in spring. In inland areas with little rainfall, water is insufficient, so when choosing a site and establishing an orchard, irrigation conditions and soil moisture conservation measures must be taken into account, and attention must also be paid to drainage measures during the rainy season.
Light conditions
The apple is a light-loving tree species and can only grow normally with sufficient light. According to measurements by Shandong Agricultural University, for Golden Delicious and New Red Star in the Tai'an area, the light compensation point is 600-800 meter-candles, and the saturation point is 3500-4500 meter-candles. Within this range, as light intensity increases, photosynthesis also strengthens. Insufficient sunlight causes a series of reactions, such as excessive vegetative growth of branches and leaves, weakness, poor resistance to pests and diseases, fewer flower buds differentiated, less nutrient storage, low flowering and fruit-setting rates, affected root growth, low sugar content in fruit, and poor coloring.
Soil environment
Soil has a great influence on the growth, yield and quality of apples. The main factors are soil layer, soil aeration and soil texture. In short, apples need deep soil, good drainage, rich organic matter, and slightly acidic to slightly alkaline conditions.
Temperature conditions
The apple tree is a temperate fruit tree that prefers low temperatures and dry conditions, and requires no severe cold in winter and no extreme heat in summer. The suitable temperature range is an annual average temperature of 9-14°C, an extreme low temperature in winter not lower than -12°C, a highest monthly average temperature in summer not higher than 20°C, an annual accumulated temperature of about 5000°C at ≥10°C, an average temperature of 12-18°C during the growing season (April to October), and 1200-1500 hours of low temperature below 7.2°C in winter to successfully pass natural dormancy. It is generally believed that apples can be cultivated in areas with an annual average temperature of 7.5-14°C. The natural dormancy period of apples is relatively long. If winter temperatures are high and cannot meet the low-temperature requirements needed for winter dormancy, spring budding will be uneven.
Judging from the regions around the world where apples are most cultivated, only when the average temperature of the coldest winter month (January in the Northern Hemisphere, July in the Southern Hemisphere) is between -10-10°C can the low-temperature requirements of apples be met. The average January temperatures in China's main apple-producing areas all fall within this limit. An average temperature of 12-18°C during the growing period (April to October), and an average temperature of 18-24°C in summer (June to August), are most suitable for apple growth. If summer temperatures are too high, with an average temperature above 26°C, apple flower bud differentiation is poor. If heat is insufficient, flower bud differentiation is also poor, the fruit is small and sour, and the color is poor, making it unsuitable for storage. As for autumn temperatures, when daytime is high and nighttime is low, the fruit has high sugar content, good coloring, thick skin, abundant bloom, and good storage quality.