It is a deciduous tree, 5 to 8 meters high, with strong growth potential. The saplings are conical in shape and will open into a natural round head shape or semicircle after fruiting. The trunk is smooth, but after more than ten years the bark is rough and cracked. The perennial branches are dark brown, the leaves are ovate or oval, with long pointed apex, round or heart-shaped base, and thorn-like serrations on the edge. The petiole is 3-5cm long. The flower buds are mixed buds, corymb racemes, each sequence has 6 to 9 flowers, and usually one fruit is set. The flowers are white, with 5 petals, 20 stamens, and 5 styles (4 in a few), smooth and hairless. The fruit is nearly spherical and oval in shape, with brown and green skin, often decalyxed. The stemness is strong, the saplings grow significantly centrifugally, and the top edge is obvious. After the new shoots sprout 2 to 3 branches, they will sprout into short branches with obvious layers (Figure 3-3). The flowering period is early, blooming first and then spreading the leaves, or blooming at the same time. The flowers at the base of the inflorescence bloom first, and the center flowers bloom later. The new shoots enter the peak growth period with the unfolding leaves, which lasts for dozens of days. The spring shoots that grow once a year can grow up to 30-40cm, and a thickness of more than 0.5cm is one of the indicators of high yield. Roots begin to grow when the soil temperature is 5°C in early spring. Generally, the root system is concentrated in the 30-50cm soil layer. The horizontal root distribution is about twice the crown of the tree. Sandy loam soil is deeper and wider than clay soil, and Sichuan pear is deeper than Douban pear. Root growth has two peaks in a year. The first is when the shoots stop growing in spring, which is the fastest growth period of the year, and the second is after the fruit is harvested. After falling leaves, it goes dormant.

Figure 3-3 Sand Pear

1. Flower branch 2. Fruit branch 3. Fruit cross section

It takes more than two years for pears to form flower buds from leaf buds. Newly planted trees It takes 4 to 5 years, and tall trees can bear fruit in 2 to 3 years. Most pear varieties bear fruit on short fruit branches, with mainly terminal flower buds and some varieties bearing axillary flower buds. Some varieties in the sand pear system can bloom 2 to 4 times a year. Yunnan Yingjiang Taiping pear blooms twice a year, and Guangdong Huiyang green pear blooms 3 to 4 times a year. The short fruit branches of pear will germinate 1 to 2 secondary shoots at the fruit platform in the current year and gradually form a group of short fruit branches. If the management conditions are good, flower buds can form in the current year and bear fruit the following year, which can last for 5 to 10 years and play an important role in stable production.

The initial stage of flower bud morphological differentiation is from mid-May to early June, and the mass differentiation stage is from mid-to-late July to August. Short fruit branches differentiate early, and medium and long fruit branches differentiate later. The quality of early differentiation is good. The fruit setting rate is high, and the flower bud differentiation period varies depending on the level of cultivation and management, tree age, and variety. It is very important to take corresponding measures to promote flower bud differentiation.

The suitable annual average temperature for sand pear is 15-21℃. Appropriate low temperature during the dormant period is beneficial to flower bud differentiation and flowering and fruiting. The temperature in the growing season in the main production area from March to October is 15.8-26.9°C (mostly 23°C), and the temperature in the dormant period from November to February of the following year is 5.0-17.0°C (mostly above 10°C); 10°C is required The above accumulated temperature is 5000~7000℃. Sand pear loves light and needs 1600 to 1700 hours of sunshine per year. Sufficient light can increase the sweetness and yield of the fruit. Insufficient light will cause the branches to become leggy, and the growth will be weak due to severe lack of light. Ventilation and light transmission should be ensured by controlling the planting density and paying attention to shaping and pruning. The growth and development of sand pear requires sufficient water and strong moisture tolerance. It is mostly distributed in areas with annual rainfall of more than 1000mm. However, too much rainfall and excessive humidity are not suitable. If the soil oxygen content drops below 2%, root growth will be inhibited. , Ditches should be dug to drain water to reduce water levels in rainy seasons, and irrigation should be done in dry seasons. Sand pears are adaptable to various soils. However, due to its weak physiological drought tolerance, sandy loam with deep soil, loose and fertile texture is most suitable. Heavy clay soil requires soil improvement.