How Should Hawthorn Orchards Be Irrigated Reasonably? A Detailed Explanation of the Technical Points
Hawthorn, an edible plant, a drupe-type fruit, hard in texture, thin in flesh, with a slightly sour and astringent taste. A deciduous shrub. Branches densely growing, with fine thorns, young branches covered with soft hairs. Twigs purple-brown, old branches grayish-brown. The fruit can be eaten raw or made into preserved fruit or fruit cakes, and after drying can be used as medicine. It is a tree species unique to China that serves both as medicine and fruit, with effects such as lowering blood lipids and blood pressure, strengthening the heart, and resisting arrhythmia. It is also a good medicine for strengthening the spleen and opening the appetite, promoting digestion and resolving stagnation, and activating blood and resolving phlegm, with good therapeutic effects on conditions such as chest and diaphragm distension, hernia, blood stasis, and amenorrhea. The flavonoid compound vitexin in hawthorn is a drug with relatively strong anticancer activity, and its extract has a certain effect on inhibiting the growth, proliferation, and invasive metastasis of cancer cells in the body.
North China often experiences spring drought and autumn drought, so irrigation in spring and autumn is a necessary condition for increasing hawthorn yields. According to the practical irrigation periods for young trees and fruiting trees in Laixi County and Fei County of Shandong Province and the Shandong Institute of Pomology, young trees can generally be irrigated 3 times, namely before bud break, during the rapid growth period of new shoots, and before freezing; fruiting trees add another 3 times, namely the fruit-setting water after flower drop, the fruit-swelling water during the fruit coloring period, and the rejuvenation water after harvest, for a total of 6 times.
(1) Bud-swelling water before bud break: From bud break to flowering, hawthorn is in a period of relatively high water demand. At this time, hawthorn sprouts, new shoots grow, the leaf canopy forms, and the floral organs further complete and differentiate, so water plays an important role in normal growth and development. At this time North China often suffers spring drought, so this watering must be ensured.
(2) Growth-promoting water during the new shoot growth period: Insufficient water supply during this period affects new shoot growth and leaf canopy formation, and further affects tree vigor and the next year's yield.
(3) Fruit-setting water after flower drop: After flowering, in May, spring drought intensifies and dry hot winds often occur. At this time hawthorn's physiological activity is vigorous, and this is the critical period for hawthorn's water demand. If the water supply is insufficient, it often easily causes severe flower and fruit drop.
(4) Fruit-swelling water during the fruit coloring period: The fruit enlargement period is also the period of hawthorn flower bud differentiation. At this time North China often suffers autumn drought, so irrigation should be carried out together with topdressing to increase the current year's hawthorn yield and promote flower bud differentiation.
(5) Rejuvenation water after harvest: Hawthorn is harvested in early to mid-October, and there are still 40-50 days after harvest before it enters the leaf-fall period. If irrigation is carried out promptly together with basal fertilizer application at this time, it can promote root growth, rejuvenate the tree, and increase storage.
(6) Overwintering water before freezing: Irrigation at this time helps safe overwintering and can provide water for spring bud break. The Baiquan Agricultural College of Henan Province measured the soil moisture content of hawthorn orchards showing different signs of drought, and pointed out that the minimum moisture content for maintaining normal growth of hawthorn trees is 10.48% for sandy loam soil and 9.34% for sandy gravel soil. The Shandong Institute of Pomology, in a river beach sandy orchard, determined that the appropriate irrigation period is when the soil content is 9%. Although different phenological periods have different requirements for soil moisture, this can serve as one of the bases for determining the timing and frequency of water demand. In view of the severe shortage of water resources in the North, it is necessary to study and improve irrigation technology and adopt advanced water-saving irrigation methods. Mulching with film after planting can effectively maintain soil moisture and increase the survival rate. Mulching with plastic film and crop straw, earthing up, and deep plowing and intertillage can increase water storage and reduce surface evaporation. Building terraces can prevent surface runoff. These agronomic techniques for dryland orchards should be inherited, carried forward, studied, and improved. Combining advanced water-saving irrigation technology with traditional dryland farming techniques can create high benefits. Using income from hawthorn to invest in water conservancy and introduce drip irrigation and sprinkler irrigation technology can save more than 2/3 of water and can greatly increase hawthorn productivity.