Key Cultivation and Management Techniques for Early Bearing and High Yield of Chinese Olive

    Chinese olive, also known as yellow olive, belongs to the Burseraceae family, genus Canarium, and originated in China. Chinese olive is hardy and easy to manage, with high yield and a long lifespan, and has relatively high nutritional value and economic benefits. The cultivation and management techniques for early bearing and high yield of Chinese olive are introduced as follows: 

　　I. Orchard site selection.Chinese olive has a long lifespan, strong adaptability, is hardy and easy to manage, and produces high yields. It is not very demanding regarding soil, but grows better on hilly gentle slopes with deep, loose, relatively fertile, well-drained soil, a slope of less than 25 degrees, and a soil acidity pH of 4.5-5.0. If a water source and convenient transportation are available, it is even more ideal. Areas with severe frost and overly heavy clay soil, low-lying land, and places prone to waterlogging are not suitable for selection as orchard sites. 

　　II. Selecting superior varieties and cultivating strong grafted seedlings.As a cultivated variety, it is essential to select superior varieties with early bearing and high yield, otherwise it will result in large production investment and small returns. Select high-yielding, superior individual trees as mother trees; for scions, use outer sun-facing branches that are short in internode length, robust, and free of pests and diseases; do not use overly vigorous or excessively elongated shade-grown branches. Use nutritional cup seedlings, with a tile placed at the bottom of the bag to inhibit deep growth of the taproot and promote lateral root growth. The strong grafted seedlings cultivated should have well-developed root systems, be free of pests and diseases, and have a trunk height of 50-70 cm. 
 
　　III. Timely and rational planting.Use nutritional cup seedlings and plant from Qingming to before Guyu. Carefully remove the nutritional cup when planting; to prevent deep growth of the taproot, cut off the taproot. The planting density should be determined according to soil quality and site conditions. Based on current production management levels, generally 18-22 plants per mu is appropriate. 

　　IV. Digging holes for planting, deep plowing and hole expansion.After digging holes for planting and backfilling soil, the soil should be more than 10 cm above ground level to prevent subsidence after planting, which could cause water accumulation during the rainy season and lead to root rot. For denser planting on mountain land, the trenching method can be used, with trenches 1 m wide and 60 cm deep, which makes water accumulation less likely. After digging the trenches, fill in sufficient organic fertilizer in layers to improve soil fertility. For sparser planting, large holes can be dug for planting, with each hole 1 m long and 1 m wide and 60 cm deep, also filling in organic fertilizer in layers. Every winter, carry out deep plowing and hole expansion to bury base fertilizer and improve the soil, cultivating a well-developed root system and promoting robust tree growth. Loosen the soil and weed the orchard 2-3 times throughout the year, keeping the tree basin loose and free of weeds; in winter, shallow-plow the entire orchard to a depth of 3-5 cun. 

　　V. Fertilizer and water management.Two months after planting, light fertilizer can be applied, mainly water-soluble fertilizer, from dilute to concentrated. Generally, fertilize 4-5 times in the first year; thereafter, apply fertilizer once each month from March to October every year, applying 20-50 jin of human manure water or decomposed soybean bran water per plant each time, adding an appropriate amount of chemical fertilizer, and frequently cultivating and weeding to promote young tree growth. Bearing trees are fertilized 2-3 times a year. The first application is in February-March (around Yushui), applying quick-acting fertilizer to promote flowering and fruiting and improve the fruit-setting rate; the second application is before and after fruit harvest to help restore tree vigor and promote the growth and fullness of bearing mother branches; the third application is in November-December as winter fertilizer to strengthen the tree and promote flower bud differentiation. Keeping the leaves of Chinese olive bearing mother branches dark green through the winter is one of the important steps to achieve high yield.
 
Chinese olive has semi-fleshy roots, with deep-growing roots that are relatively drought-tolerant and averse to waterlogging. It is prone to water accumulation in spring and summer that damages the roots, so drainage work should be done well, and in autumn and winter, drought prevention and moisture retention should be done well. For young trees, the main focus is to keep the tree basin covered year-round to maintain soil moisture; for bearing trees, water demand is higher during new shoot growth and panicle emergence in April-May. During the fruit enlargement period, drought can easily cause massive fruit drop. If conditions permit, timely irrigation or watering should be carried out, along with loosening the soil and covering with weeds to maintain soil moisture, which helps retain fruit. 

　　VI. Training and pruning.Keep the trunk height at 50-70 cm, then select and retain 3 evenly distributed, robust new shoots as main branches. For primary and secondary branches, retain about 40 cm and pinch or cut back. Excess buds and sprouts below the graft union should be promptly removed. For subsequent flushes, thinning of buds and pinching should be carried out to cultivate a high-yielding canopy with a low trunk and short main stem. If young trees produce flower panicles, they should be cut off early to concentrate nutrients for expanding the canopy. For bearing trees, after fruit harvest in autumn and winter, prune dead branches, pest- and disease-damaged branches, crossing branches, overly dense branches, and senescent branches.
 
　　VII. Flower promotion.For trees that are overly vigorous and have not yet entered production when they should have, measures such as girdling, root pruning, water control, and chemical regulation can be used to promote flower bud differentiation. 

　　VIII. Flower and fruit retention.At the bud stage, flower-fall stage, and young fruit stage, spray fruit-retention agents such as nucleotides, Guoteling, and Baoguosu respectively, or spray 0.2% borax plus 0.3% urea to retain flowers and fruits and improve the fruit-setting rate. 

　　IX. Pest and disease control.Chinese olive has relatively few diseases. The main pests include nematodes, leafhoppers, scarab beetles, aphids, psyllids, and longhorn beetle larvae, which can be controlled with trichlorfon, Wanling powder, and others. In winter, use lime-sulfur mixture residue or whitewash (made from 1 part lime, 1 part water, 0.1 part sulfur powder, plus a small amount of salt to make a lime slurry) to whitewash the trunk and main branches, preventing frost and pests and diseases while protecting the trunk.