Lucuma nervosa (Lucuma nervosa plant)
Lucuma nervosa (Latin scientific name: Lucuma nervosa A.DC), also known as fairy peach, Lucuma nervosa is a perennial plant of the family Lucumaceae. The tree is about 6m high, with single and alternate leaves. , the leaves are papery, narrowly oval, and the flowers are small white and clustered in the leaf axils.
The fruit is spherical, green when unripe, yellow-green to orange-yellow when mature, smooth, thin-skinned, orange-yellow flesh, rich in starch, with a texture like egg yolk and aroma, low water content, and a slightly sweet taste. Its taste is somewhere between sweet potato and durian. Seeds are usually 1-2, nearly round or oval. The fruit matures in December and needs to mature for 4-7 days after harvesting before it can be eaten.
Morphological characteristics
Small tree , about 6m high; branchlets are cylindrical, gray-brown, and the young branches are covered with short brown hairs. The leaves are firm and papery, narrowly oval, 10-15 (20) cm long, 2.5-3.5 (4.5) cm wide, apex acuminate, base wedge-shaped, hairless on both sides, midrib slightly convex above, rounded and very convex below. , 13-16 pairs of lateral veins, rising obliquely to the edge of the leaf in an arc, obvious on both sides, the third vein is reticulated, obvious on both sides; the petiole is 1-2cm long.
1 (2) flowers are born in the leaf axils, the pedicels are cylindrical, 1.2-1.7cm long, covered with brown fine hairs; the calyx lobes are usually 5, rarely 6-7, oval or broad-ovate, about 7mm long and 5mm wide. , the inner surface is slightly longer, the outer surface is yellow-white fine hairs, the inner surface is hairless;
the corolla is longer than the calyx, about 1cm long, the outer surface is yellow-white fine hairs, the inner surface is hairless, the crown tube is cylindrical, about 5mm long, the corolla lobes (4) 6, narrowly ovate, about 5mm long;
fertile stamens usually 5, filaments diamond-shaped, about 2mm long, covered with white very fine hairs, anthers heart-shaped oval, about 1.5mm long;
staminodes Narrowly lanceolate to subulate, about 3mm long, covered with white very fine tomentose; ovary conical, 3-4mm long, covered with yellowish-brown tomentose, 5-loculed, style cylindrical, 4-5mm long, hairless, Stigma capitate.
The fruit is obovate, about 8cm long, green and egg-yellow, hairless, the exocarp is extremely thin, the mesocarp is fleshy, thick, egg-yellow, edible, tastes like egg yolk, hence the name egg-yolk fruit; 2-4 seeds, oval Shape, flattened, 4-5 cm long, yellowish brown, shiny, scarred laterally, oblong, almost as long as the seed. The flowering period is in spring and the fruiting period is in autumn.
Growth habits
Egg yolk fruit likes a warm and humid climate, with an average annual temperature of 24-27.5°C. It can withstand short-term high temperature and cold, and the plants will not be damaged for short periods of time at 40°C or 1-2°C. During the flowering period, rainy and high temperatures will cause serious flower drop. Avoid low temperatures during the fruit ripening period. The fruits will harden at low temperatures in winter. It is quite drought tolerant and has strong adaptability to soil. It grows best in sandy loam soil.
Origin and distribution
Egg yolk fruit is native to Cuba and North America tropics. It is mainly distributed in Central and South America, northeastern India, northern Myanmar , Vietnam , Cambodia , Thailand, and southern China. China introduced it in the 1930s, and cultivation began in Guangzhou in the 1950s. There are sporadic plantings in tropical and subtropical areas such as Guangdong, Guangxi, Hainan, Yunnan and Fujian in China.
Cultivation technology
Garden selection
Large peach-shaped and small peach-shaped egg yolk fruits can be planted in a relatively flat place with sufficient sunshine, deep soil, fertile soil, sufficient water source, convenient drainage and irrigation. In places with thick soil but poor soil and insufficient water sources, it is better to plant spherical and spindle-shaped egg yolk fruits.
Garden planting
Planting hole preparation
The spacing between rows of plants for gentle planting is 3mĂ—4m, and the planting holes are 100cmĂ—80cmĂ—60cm; the spacing between plants for planting on slopes is 4mĂ—4m, and the planting holes are 100cmĂ—100cmĂ—60cm. Use green manure for planting holes, and layer soil and miscellaneous fertilizers to press green. When planting, mix 450-100kg of manure and 0.5kg of superphosphate per hole.
colonization
is generally planted 3-6 months after the new shoots of the seedlings mature or before the new shoots are drawn. Seedlings should be transplanted with soil to avoid damage to the root system. If soil cannot be carried, the thicker injured roots should be cut flat after the seedlings are raised, soaked in a liquid prepared with ABT rooting powder, then dipped in yellow mud, then tied with wet straw and film, and transported to the field. When transplanting with or without soil, some twigs and leaves should be cut off before the seedlings emerge. Before planting, soak the planting hole in water, cultivate with water, and cover with soil and grass. After planting, prevent shaking from damaging the roots and keep the soil moist.
Management measures
Fertilizer and water management
Young trees
Fertilize according to the principle of thin application and frequent application one month after planting. Fertilize once a month, 20g of urea and 410g of potassium dihydrogen phosphate for each plant; from September to February of the following year, every Fertilize once every 2 months, with 20g of urea and 10g of potassium dihydrogen phosphate applied to each plant. Apply 30g of urea and 15g of potassium dihydrogen phosphate every month from March to August of the second year; from September to February of the following year, fertilize once every two months, with 30g of urea and 20g of potassium dihydrogen phosphate applied to each plant. In the third year, most of the saplings begin to bloom and bear fruit. At this time, the flowers should be picked and the amount of nitrogen fertilizer applied should be increased to promote the vegetative growth of the saplings. In the third year, 50g of urea and 15g of potassium fertilizer were applied to the plant every month; from September to February of the following year, fertilizer was applied every two months, with 50g of urea and 20g of potassium fertilizer applied to the plant. Egg yolk fruit production begins in the 4th year. Pay attention to irrigation throughout the sapling stage to ensure normal growth.
The adult tree
The egg yolk fruit will enter the high-yield period after 4-5 years of planting. Apply flower-stimulating fertilizer before the first flowering and at the end of March. Apply 100g of urea, 100g of potassium sulfate, 50g of superphosphate, 50kg of borax 5 and clean manure water, and a small amount of trace elements. 25% of the year. In early July, apply male fruit fertilizer, including 100g of urea, 150g of potassium sulfate, 150g of superphosphate, 5kg of dried oil, and 50kg of clear manure water. Apply it in a radial shallow ditch, and the amount of fertilizer accounts for 50% of the whole year. Egg yolk fruits bear fruit every year, but mid-October and mid-February are the two peak periods for fruit picking. In mid-February, mature fruits account for 85% of the whole year, and the fruit quality is the best. Therefore, fruit fertilizer application should be carried out in mid-to-late February. Dig trenches under the vertical line of the crown width, and apply 50kg of manure and 0.5kg of quicklime to the plants. At the same time, spray foliar fertilizer. During the fruit-growing period, water supply must be ensured. Water should be controlled appropriately before flowering to promote flower bud differentiation. Water should be controlled after the fruit matures to prevent fruit cracking.
Soil management
Using grass covering method can prevent the growth of weeds, increase soil moisture and improve the physical and chemical properties of the soil. The best covering material is magnolia. At the same time, hole expansion and soil modification should be planned according to the growth status of the saplings. Light plowing is used to remove weeds inside the tree tray, and weeding is used to cover the outside of the tree tray to reduce weed growth.
Pruning and pruning to preserve flowers and fruits
Saplings
In order to make saplings bear fruit early, saplings should focus on vegetative growth in the first 3 years and cultivate a good tree structure. The crown of the tree adopts a natural semi-circular head shape. When it enters the peak production period, it is necessary to thin less and leave more, and cut it lightly and plant more. In the third year after planting, the flower buds of the egg yolk fruit will differentiate, and all flower buds must be wiped out to ensure vegetative growth. For 4-year-old trees, shorten the middle and upper branches of the crown in summer to control the crown yield within 5kg/tree. Immediately after each pruning, 1-2 degrees lime sulfur mixture is fully sprayed, evenly inside the crown, outside the crown, and on the trunk. After that, the output gradually increased, and it officially entered the peak period in 8 years.
Adult tree
Pruning after fruit harvesting: On the basis of maintaining a good tree structure, a major pruning is performed after fruit harvesting, the fruiting mother branches are rotated and updated, and a robust fruiting mother branch group is cultivated on the main branch and the deputy main branch. . The number of fruits on the secondary main branch accounts for 80% of the total number of fruits. At the same time, cut off dead branches, weak branches, diseased branches, shade branches, leggy branches, retracted cross branches, fallen branches, etc. In areas with relatively flat terrain, it is necessary to dredge the rows of tree crowns and keep the distance between rows at 60-90cm to ensure ventilation and light transmission in the orchard. After pruning, spray 1-2 degrees lime sulfur mixture on the entire crown of the tree.
flower bud period management: from April to June after budding to the full flowering period, control the shoots and the amount of flowers according to the number of new shoots, the amount of flowers and the tree vigor, which are specifically divided into three categories: the first category, the tree vigor is strong, the flowers are If there are many new shoots and few new shoots, the main purpose is to control flowers. Prune off too many, too dense, too weak flowering branches or branch groups in the crown;
Category 2: The tree vigor is medium, and the number of flowers and fruiting branches is moderate. The main method is shoot control, which involves cutting off 50% of the new shoots outside the crown and the branches with fruit stalks and the middle and upper part of the crown, and erasing the long summer shoots; the third category, medium tree vigor, few flowers, and many new shoots, is completely based on shoot control. Mainly, the summer shoots inside and outside the crown should be repeatedly pruned until the flowering stage, and the new leaves should not exceed 40% of the old leaves.
Fruit preservation: Spray fruit preservation agent in time, 2,4-D5-10mg/L, gibberellin 5-10mg/L or 20-40mg/L and other plant growth regulators.Fruit thinning: 12 weeks after two physiological fruit drops (the second physiological fruit drop in the 6th week of egg yolk fruit setting, the fruit drop rate is low, 0.3% of the total fruit drop), timely thin out diseased fruits, deformed fruits, and Too dense small fruits, fallen fruits and top fruits. Depending on the variety, tree vigor determines the amount of fruit thinning, but a maximum of 2-3 fruits can be left per inflorescence.
Disease and Pest Control
Egg yolk fruit has few pests and diseases. Common pests include scarabs, termites and a small amount of scale insects.
Bagging Egg yolk fruit bagging can prevent sunburn, reduce damage from pests and diseases, and especially prevent birds from pecking. Use double-layer breathable paper bags for fruit bagging. Spray fungicide once before bagging. Choose a sunny day for better results.
Cockchafer
Cockchafer mainly damages young leaves and shoots from spring to summer. It can be controlled with 1500 times dimethoate, or the phototaxis of adults can be used to trap and kill with black light at the edge of the orchard.
Termites
White ants mainly harm the rhizomes of old trees and can be controlled with 48% Lesbon 1000-1500 times liquid.
Scale insects
A small amount of scale insects can be sprayed with 40% Supu Kill 100-500 times, which has a certain control effect.
Soot disease
Sooty disease occurs on flowers and fruits. In the early stage, spraying with 0.1:1:100 Bordeaux mixture or 400 times of sterilization solution can inhibit the spread of the disease.
Main value
Edible
Yolk fruit is a tropical fruit. The pulp contains 29.1-30.5% sugar, 5.6-8.1% starch, crude fat 1-1.14%, and every 100 grams of pulp contains 24.3 mg of vitamin C.
In addition to being eaten raw, the fruit can be made into jam, ice cream, drinks or fruit wine.
Hainan egg yolk fruit beauty benefits: Egg yolk fruit is rich in phosphorus, iron, calcium, vitamin C, carotenoids and other nutrients and seventeen kinds of amino acids necessary for the human body. It can help digestion, reduce phlegm, nourish the kidneys and refresh the mind. It has the functions of refreshing the brain, activating blood circulation and strengthening the body, sedating and relieving pain, reducing stress and lowering fat.
Economical
Egg yolk fruit trees are beautiful and suitable for garden cultivation.
The egg yolk fruit has excellent characteristics of being suitable for planting on sandy soil and other soil textures. It is a second-generation female fruit tree;
The market price of this fruit per kilogram is between 20 and 55 yuan. It is a fruit tree planting variety with great market prospects. It is also a It is an effective way to solve the problem of aging varieties and low market prices in the rural fruit planting industry and to increase the income of rural farmers.
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