Moisture is the basis for the growth and development of citrus. Irrigation water consumption during production is large, and the normal growth period requires annual rainfall of 1000-1500 mm.
Citrus is a fruit tree with shallow root system, and more than 90% of its fibrous roots and absorbing roots are distributed in the soil layer of 10-40cm.
The suitable soil moisture content for growth and development is 60-80% of the field water capacity, and the water requirement for producing 1kg of citrus fruits is 0.5-0.75m3/acre; if the annual rainfall during the growth period is less than 1000mm, the overall fruit size will become smaller and the flavor will be poor.
The summer growth period and fruit expansion period require more water, with a daily water requirement of 3.0-3.9mm; from December to January of the following year, the fruit maturity and dormancy period require a daily water requirement of 0.2-0.8mm.
Spring drought in southwestern production areas affects the spring growth, flowering and fruiting of citrus; autumn drought is common and affects fruit enlargement; winter drought affects fruit maturity and flower bud differentiation. The fundamental measure to solve the problem of seasonal drought and water shortage is to vigorously develop high-efficiency water-saving technologies and accelerate the transformation of irrigation methods from inefficient and extensive to suitable for production and high-efficiency.
