Lemon tree eureka

Lemon tree eureka. lemon cultivar obtained in California by Thomas Garey in 1858 , possibly obtained from cv. Lunary. It belongs to the Rutáceas family , specifically to the Citrus genus .


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  • 1 Origin
  • 2 Tree characteristics
    • 1 The leaves
    • 2 The flowers
    • 3 The fruits
  • 3 Fruit quality
  • 4 Ripening season
  • 5 Business experience
  • 6 Propagation
  • 7 Climate
  • 8 Floor
  • 9 Cultural Practices
    • 1 Fertilization
      • 1.1 How is the subscriber calculated?
      • 1.2 When do you have to pay?
    • 2 Irrigation
    • 3 Pruning
    • 4 Harvesting and handling
    • 5 Performance
    • 6 Planting framework
  • 10 Pests and diseases
    • 1 Pests
      • 1.1 Citrus miner
      • 1.2 Aphids
      • 1.3 Mealybugs
      • 1.4 Wonder Mite
      • 1.5 Citrus Moth
      • 1.6 The whitefly
      • 1.7 Fruit fly
    • 2 Diseases
      • 2.1 Citrus nematode
      • 2.2 Gomosis
      • 2.3 Alternaria alternata
      • 2.4 Virus of sadness
    • 11 Properties and Uses
    • 12 Sources


Eureka plant

It was obtained in California in 1858 from a sowing of lemon seeds imported from Italy , possibly from cv. Lunary. Years later, a selection was made of these plants, which were propagated by an important nurseryman from Los Angeles , Thomas Garey , who introduced them to the market with the name of “Garey’s Eureka”.

In the more than 100 years of cultivation in California , many clone selections of Eureka have been made, which have been given their own names. Some of these clones correspond to nuclear selections, such as the Eureka Frost, which were made for the purpose of clonal rejuvenation and virus and viroid sanitation.

This variety has spread in almost all lemon producing countries. A Chile was officially introduced in 1943 , although different selections have been reintroduced in several occasions. Probably the most spread selection in Chile in recent years is Eureka Frost.

Tree Characteristics

This variety has spread in almost all lemon producing countries. Eureka is one of the 2 main cultivars in California , although it is now being replaced by clonal selections, with more vigor, for example, ‘Allen’, ‘Cascade’, ‘Cook’ and ‘Ross’. ‘Lambert Eureka’ is a variety from seed found in 1940 on the Horace Lambert property in New South Wales . It is vigorous and productive.

Medium-sized tree, almost without spines, early, prolific, not especially vigorous, sensitive to cold, and not resistant to insects, relatively short life, with an open growth habit, with few spines.

It has a sypodial growth habit with little lateral branching, with a structure that is formed on suckers that fall and sprout at the base, so that formation pruning is important during the first years.


Alternate leaves, Reddish when young, dark green above, light green below, oblong, elliptical, or long ovate, 2 1/2 to 4 1/2 Inches (6.25-11.25 cm) long, finely serrated , with thin wings on the petiole.


It presents a long spring fluoridation and is flourishing, so its harvest period is quite extended and produces an abundant summer harvest. The flowers with a soft fragrance may be solitary or there may be 2 or more grouped in the axils of the leaves. When they sprout they are reddish in color; the open flowers have 4 or 5 petals 3/4 inches (2 cm) long, white on the upper surface (inside), purple below (outside), and about 20 to 40, stamens with yellow anthers attached.

The fruits

Its fruit is a productive variety, very early in production and with fruits that tend to be located on the periphery of the tree, often in clusters at the tip of the branches.

The fruit is elliptical to oblong, with the nipple moderately protruding at the apex, a low relief collar at the base, yellow skin, with longitudinal ridges, slightly rough due to the sunken oil glands, moderately thick, and not easily separable of the pulp; greenish-yellow pulp, with about 10 sectors, fine-grained, tender, juicy, very acidic, with a high content of Vitamin C and [[citric acid].

The fruits are often produced in large clusters at branch terminals without foliage protection. It produces all year round, but more in late winter, spring and early summer when demand is high for lemons.

Fruit quality

Fruits of the Eureka Plant.

The fruits are of good size and elliptical in shape, normally have a small neck at the base of the fruit and a small apical mamelon that is sometimes surrounded by an areolar groove. It has a good juice content with high acidity and low number of seeds. Although it produces very fine and good quality fruit, many times the export percentage is low due to the irregularly shaped fruit production and the large amount of exposed fruit that is produced in the periphery of the glass and that is damaged by blow of Sun, wind damage and low temperature tan. Both formation pruning and production pruning should be geared towards generating and maintaining fruit production towards the inside of the crown.

Ripening time

Fruit can be harvested throughout the year, although the main harvest occurs in winter (70%), concentrating its main export harvest in June and July , in the central zone. It presents an abundant autumn bloom that generates an interesting summer production (30%), the magnitude of which is strongly determined by the winter frost regime.

Commercial experience

Today it is perhaps the most widespread lemon variety in the world, widely planted in California , South Africa , Chile and Australia.. It can produce two harvests, the first and most important, it is harvested in the same period as the Fino variety or a little earlier. Very productive variety, with a tendency to fructify at the ends of the branches. It is sensitive to cold and wonder mite. Due to its high productivity and rapid entry into production, Eureka should remain popular for years to come. Its main limitation in the future will come in replanting situations, due to the lack of compatible graft carriers that are tolerant to nematodes. In such circumstances, many growers will have to replant with another variety of lemon tree that is compatible with suitable rootstocks for replanting situations.


Sexual propagation through seeds presents a series of disadvantages: they give plants that have to pass a juvenile period, which are also much more vigorous and have heterogeneity. Therefore, asexual propagation is preferable, specifically by means of a graft from gusset to yolk. If re-grafting is required to change the variety, the veneer graft can be made, which also gives very good results.


Due to its more or less continuous growth, the eureka is more sensitive to cold than orange and less able to recover from injuries due to it. A drop in temperature causes serious damage to woody parts. Therefore, lemon has a relatively limited climatic range. Lemons are grown in humid and dry environments, the latter being a disadvantage, mainly in the curing and storage processes. In a large lemon growing region in California , annual precipitation ranges from 25 to 125 cm. If there are long dry periods, the lemon should be watered.


The lemon tree has a reputation for tolerating infertile or very poor soil. In Florida , most of the plantations are on sand. In California , it maintains excellent growth in silty clay loam with a high water-holding capacity. Black soils are also suitable if they do not extend over calcareous subsoil. The Ph must be between 5.5 and 6.5. If the acidity is high, it is necessary to apply lime to achieve the optimal level.

Cultural Practices


You need a lot of fertilizer rich in macronutrients Nitrogen , Phosphorus , Potassium and Magnesium , micronutrients. There are two different subscriber options: one Biological and the other mineral: 1.Biological: Compound Fertilizer Trivalent BIO NPK 8-6-6 + MO 88% 2.Mineral: Complex Fertilizer SUPRAMIX NPK 12-10-18 + 2 Mg

How is the subscriber calculated?

We must take into account two factors:

  • The height of the tree – each meter of height equal to 150 Gramsof compost for growth
  • Lemon production – every 10 kilos 200 gr of fertilizer for production.

The greater the production or size of the tree, it is necessary to increase the proportional part of the fertilizer that corresponds to it.

When do you have to pay?

The fertilization can be done 3 times a year from mid- November and late April , the rate gradually increases 4 to 10 pounds (1.8-4.5 kg) per tree until an age of 50 years.


They need a lot of water. They should be watered regularly throughout the year. The irrigation must be made to coincide with the subscriber. Heavy watering increases the yield and oil in the peel, the infection with crust, the size of the fruits and accelerates the maturity.


Trees should be pruned when young and kept below 10 or 12 feet (3-3.6 m) in height. They are drastically cut after 12 years or replaced. Supports flowering pruning, cleaning pruning and rejuvenation pruning. Excessive pruning should not be done, especially in the first years of growth. Remove dry branches. Trees that are not pruned flourish abundantly, but later become unmanageable.

Harvest and handling

The marketability of lemons depends on the phase in which they are collected, in California the eureka lemon needs to be collected earlier, and they adopted the practice of harvesting them at any time after the fruits reach 25% juice content, and the use of rings to measure commercially acceptable height. Mechanical harvesting is impossible for lemons.

The fruits are highly prone to staining (oleocellosis) and cannot be handled or picked abruptly or even wet. Some growers have found that this manual harvesting in detail is too expensive, and now they harvest the entire harvest at once and are sorted for sale or for processing at the packing center, discarding all under-sized fruits. The lemons, after color grading, washed, coated with a fungicide and a thin layer of wax are stored (cured) until ready for transport.


Lemon tree yield varies considerably with cultivar, location and weather conditions. A yield of 3 boxes per tree is commercially satisfactory.

Plantation frame

It is larger than the orange tree, so the plantation frames are wider (7.5 x 7.5), although they are variable depending on the experience of the farmer. Not well suited to hedge.

Plagues and diseases


Citrus miner

Phyllocnistis citrella . It attacks the young leaves of the lemon tree and its larvae live in galleries, also called mines, between the leaves. The caterpillar is greenish-yellow. For its control, carry out treatments based on active substances such as Abamectin, Lufenuron, Benfuracarb, Carbosulfan.


They cause the weakening of the plant in massive infections, which is when there is a large emission of molasses accompanied by stiffening of the leaves. For its control, carry out treatments based on active materials such as Acetate, Alpha Cypermethrin, Benfuracarb, Butocarboxim, Dimethoate, Carbosulfan, Endosulfan, Permethrin, Pirimicarb, Imidacloprid.


Its damages consist, essentially, in the subtraction of sap that causes a general depression throughout the plant, in addition to producing molasses, a sugary liquid responsible for the countless ant colonies. For its control, carry out treatments based on active ingredients such as Summer Oil, Buprofezin, Etion, Napropamide.

Wonder mite

Aceria tulipae . It especially attacks the lemon tree, causing damage such as deformations and reduced growth. It also produces the fall of small fruits and the fruits that manage to progress have intense deformations. For its control, carry out treatments based on active materials such as Bromopropylate or Pyridafention.

Citrus moth

Prays citri . The larvae link the attacked flowers with silks. These, almost transparent brown gray color, feed on the turgid floral organs and then exit through a lateral hole to go to another flower bud. In lemon cultivation, the caterpillar penetrates the epidermis of the fruit and pierces a gallery that exudes rubber through the penetration hole. For its control, carry out treatments based on active substances such as Flucitrinate, Isoxation.

The white fly

Aleurothrixus floccosus . They are sucking, with an articulated beak and four membranous wings that fold in a canopy. Adults inhabit the underside of the new leaves, they fly little and are easily dragged by the wind, constituting the main means of invasion of new areas. As all the evolutionary stages secrete a large amount of molasses, it makes the leaves dirty, hindering the photosynthesis and respiration of the tree, affecting the performance of work, production and quality of the fruit. Adults and larval stages weaken sprouting and can cause defoliation due to its sucking action. For its control, carry out treatments based on active substances such as Butacarboxim, Buprofezin and Lufenuron.

Fruit fly

Ceratitis capitata . It is a somewhat smaller fly than the common one with green eyes, a silver gray thorax and a yellow abdomen with two gray bands. The female is equipped with a pointed drill that serves to make the laying on different fruits. The larvae hatching from these eggs are white and elongated. The female pierces the skin of the fruit to deposit the eggs. In 3-5 days the larvae hatch causing the decomposition of the pulp. For its control, carry out treatment based on active ingredients such as Fention, Trichlorfon, Malation.


Citrus nematode

Tylenchulus semipenetrans . This disease develops gradually and begins with a reduction in the number and size of the fruits. The main symptoms are: lack of vigor of the plantations and reduction of the caliber of the fruits. For its control, carry out treatments based on active materials such as Cadusafos, Oxamilo or Aldicarb, although it is convenient to approach the crop well by buying plants with resistant patterns such as the “Citrumelo swingle” and the “Poncirus trifoliata”. The most effective control method is the combination of preventive measures such as keeping the field well drained, taking care that the irrigation water does not wet the tree trunk, being careful not to damage it with the work tools, avoiding periods of drought followed by watering abundant, moderate nitrogen fertilization.


This disease rots the trunk and roots. The affected area darkens and dehydrates since the sap cannot drain it and ends up drying out. The leaves become more pointed and yellow, the shoots weaken and the fruits are smaller. The bark of the trunk separates, producing a sticky substance around it. Avoiding excess moisture is the best way to prevent it.

Alternaria alternata

Necrosis occurs in the leaves, stems and fruits almost completely, once infected the fruit ends up falling from the tree. Avoid exceeding the nitrogen when fertilizing it for its prevention and in the event that the disease appears we will get rid of the affected parts.

Sadness virus

Citrus sadness virus – CTV . This virus causes one of the most serious diseases. Little by little the crown loses volume and the leaves and branches dry up, the fruits that acquire a paler color decrease and finally the tree dies. The brown aphid and cotton are responsible for this disease. The technique, Elisa is used to recognize and control CTV viruses. The combination with anti-aphid nets allow the germination of plants free of these aphids.

Properties and Uses

  • Medicinal
  • It has a high content of vitamin C and citric acid.
  • Origin of pharmaceutical products.
  • Digestive, stomach, astringent, dermatological, analgesic, influenza …
  • It awakens the appetite and facilitates digestion.
  • Fat Solvent (Weight Loss Diets)
  • Excellent anti-dandruff, healing.
  • Gastronomic
  • Season fish and shellfish. (Antibacterial)
  • As an ornament in alcoholic beverages or soft drinks.
  • To make desserts or natural drinks such as lemonade.
  • Others


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