Tropical and subtropical regions are ideal for lemon trees, requiring enough sunlight to yield brightly colored fruits. To ensure healthy growth, lemon trees must be planted at least 5 meters between each other. Digging 60 x 60 x 60 cm pits guarantees good soil for seedling germination.
After planting, these trees usually begin to bear fruit after three years and reach their peak yield by the fifth year. Lemon trees, known for their prickly branches, provide a natural barrier against their valuable fruits. The best time to plant lemon trees is early in the spring, in March. Lemon trees are highly valued in many cultures due to their delicious, yellow fruits and fragrant flowers. They are loved all over the world.
Growing lemons is more than just planting and waiting; it’s a labor-intensive process that requires extreme care in detail at every stage. This comprehensive manual covers every topic, including the intricate technique of harvesting and caring for plants after harvest, as well as pruning and encouraging bud growth.
Lemons are native to South Asia, namely the northern Indian foothills of the Himalayas. They are grown all over the world and are loved by foodies for their delicious fruits and aromatic flowers.
How to care for a lemon tree?
Pruning
Partially removing sections of a plant to promote growth and health is known as pruning, and it is a basic horticulture practice.
This is usually done in August in lemon orchards after completing the harvest to help reshape the trees, remove diseased or dead branches, and improve airflow. Adequate penetration of sunlight is a critical factor in the general health of trees, hence taking such steps is essential.
Flowering and fruit sets are facilitated by sunlight, which also affects the color and quality of the fruit. Still, over-pruning should be avoided as it might cause a delay in fruit production, particularly on young trees that don’t yet bear fruit. In young trees, healthy development is usually promoted by removing only sprouts on the trunk.
Lemon trees have many branches that need to be pruned, such as dead, water shoot, overlapping, and infected branches. Pruning strategies have a substantial impact on several aspects of lemon production, and different pruning approaches produce diverse results.
For example, the greatest number of flowers, fruit retention, and total fruit yield were obtained using the pruning procedure. Pruning, however, can also impact when fruit is harvested, as seen by the delays in peak fruit harvesting that are linked to pruning techniques.
It is best to avoid applying too much nitrogen after heavy pruning as this can make matters worse and have unfavorable effects like thicker fruit skin.
It is ideal to prune trees in late winter or early spring, when they are dormant, to promote faster wound healing and lessen stress on the tree. Efficient pruning methods not only guarantee a healthy lemon crop but also greatly extend the life and yield of the tree.
Five advantages of Pruning lemon tree.
- Pruning caused better movement of air and light into the inner part and thereby resulted in greater photosynthesis.
- Pruning also encouraged dormant buds to put forth new shoots owing to the absence of apical dominance.
- Pruning aids disease prevention in lemon trees by enabling early detection and removal of infected or damaged branches, effectively reducing the risk of disease spread.
- The highest number of flowers, fruit retention, and fruit yield was recorded in light pruning plants.
- Pruning allows you to shape your plants for aesthetic purposes.
Stem Pasting
After pruning, stem pasting serves as a vital protective measure. This process entails applying a protective substance onto the cut surfaces of the branches to establish a barrier against potential infections such as citrus gummosis.
By doing so, pathogens are prevented from infiltrating the tree through the pruning wounds, thereby safeguarding the long-term health and vigor of the lemon trees. Research has shown that stem pasting with Bordeaux mixture, specifically up to a height of 1 meter from the ground level, proved to be notably effective in halting complete oozing.
Weed Control
The decrease in yield caused by weed competition results in an approximate loss of 23% to 33% for farmers. Weed competition tends to be particularly challenging during the initial establishment phase. Young citrus trees, lacking substantial shade, receive irrigation and fertilization to promote growth, inadvertently encouraging weed proliferation.
Weeds not only vie for essential nutrients and water but can also act as alternative hosts for pests and diseases, exacerbating yield reduction in citrus crops. Additionally, weeds can lower soil temperatures during freezing periods and impede grove operations such as harvesting.
Weed can be controlled by three methods:
Manually
By using labor.
By using machines
By using herbicide.
Herbicides play a major role in citrus grove weed management. Of all the herbicides available to producers for controlling weeds in lemon cultivation, glyphosate is the most often used. In citrus orchards, glyphosate is used alone or in combination with pre-and post-emergence herbicides to efficiently eradicate a variety of weeds. Due to its ability to effectively eradicate a wide variety of weed species and its affordable price, glyphosate has become an indispensable component of many weed management plans.
Fertilizer Application
Fertilizer application in September and October is an important part of orchard management. It provides the nutrients that lemon trees need to thrive, matching their growth cycle. Fertilizers are important because they promote strong tree growth and provide lemon trees with the resources they need for the best possible flowering and fruit production in the next season.
During the spring and summer growth seasons, it is imperative to use a fertilizer that has a balanced ratio of potassium, phosphate, and nitrogen, such as 10-10-10 or 14-14-14, and to apply it every 4-6 weeks. In order to support the natural growth patterns of lemon trees, do not fertilize them during the winter.
For the root system of the lemon tree to effectively absorb nutrients, proper application methods are essential. Make a ring around the tree that is as broad as it is tall when applying fertilizer. By using this technique, the nutrients are made available to the complete root system by encouraging their penetration into the soil where the roots are found.
A plentiful harvest in the future depends on the continued healthy growth and development of lemon trees, which is supported by regular fertilization applied once a year during the growth phase.
Year-wise requirement of Vermicompost (Kg / Plant / Year)
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Year-wise requirement of various nutrients (g / plant/year)
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Lemon fertilizer schedule
The recommended dose of fertilizer is applied generally three times a year, in late February, June, and October. Avoid any kind of fertilizer application during winter as plants are in the dormant stage and are not able to utilize nutrients properly.
Irrigation
Proper irrigation post-fertilizer application in September/October is vital for lemon trees. It helps them efficiently absorb nutrients, fostering healthy root development and overall vigor. Water scarcity significantly impacts citrus orchard productivity and health.
Citrus, a high-water-demanding perennial fruit crop, thrives mainly in tropical regions. Adequate irrigation is crucial for success in these areas. Water stress during specific growth stages can enhance citrus yield and fruit quality.
Critical lemon growth stages, like flowering, fruit set, and fruit development, are highly sensitive to water stress. Insufficient soil moisture during these phases drastically reduces yield. Continuous irrigation from June to October leads to higher lemon yields.
Watering regularly is crucial, particularly in hot, dry weather. At least once a week, or more frequently if the top two inches of soil are dry, lemon trees need to be properly watered. But to avoid root rot, avoid overwatering.
Flowering
The lemon flower has a perfect bisexual reproductive system and is characterized by its lovely aroma and white color. It has five fused sepals, generally with white petals, that create a small cup. Twenty to twenty-five stamens are grouped in a columnar whorl around the gynoecium.
Most commercially grown types have a carpel consisting of 10 to 14 fused units. The carpel’s stigma is distinctively shaped like a narrow donut. The ovary is compound, spherical, superior, and green, with 10–14 locules, each representing a carpel.
Many cultivars are self-pollinated. Bud development in January is crucial for future flowering and fruit-setting, requiring protection from cold damage. Lemon trees typically reach maturity when they start forming light pink or purple clusters of flower buds near stem ends.
March is when flowers typically bloom because of the chilly nighttime temperatures. Flowering is a crucial phase in the reproductive cycle of the lemon tree that results in the formation of fruit.
Spraying during flowering should be avoided as it may cause problems with the fruit set. For optimal fruit development, there should be adequate moisture during flowering.
Growth stages of lemon flower
Bud initiation
Floral buds in lemon begin to appear in February.
Bud development
Bud takes 20–25 days to become completely mature for blooming.
Bloom
Avoid any kind of spray during blooming as it may hamper pollination.
The pollination process starts as soon as the bud opens.
Pollination
Lemon trees are primarily self-pollinating, meaning they can produce fruit with their pollen, but cross-pollination can enhance fruit yield and quality.
Bees are crucial pollinators for lemons, transferring pollen between flowers as they forage, thereby facilitating fruit production.
Care tips after flowering.
Spray against Citrus Canker
- Small fruits are more susceptible to citrus canker up to 90 days after petal fall.
- During that time, apply 3–4 Sprays to prevent citrus canker at intervals of 15-20 days.
Control Fruit Drop
- Zinc sulfate along with borax sprayed 1-2 times on the leaves of plants prevents fruit drop and increases production.
Regular Watering
- 1-2 times water is sufficient. Apply water when the soil dries about 2 inches below the surface.
- Avoid overwatering, as this can lead to root rot.
Pruning and Thinning
- Prune away dead, diseased, and damaged branches.
- Thin out overcrowded branches to promote new growth.
- Fruit has a good color when light penetrates it properly.
Fertilizer Application
- Apply the recommended dose of fertilizers in late February (1st dose) and in June (2nd dose).
Spray against Leaf Miner.
- Citrus leaf miners are well controlled by parasitic wasps.
- Systemic insecticides (imidacloprid, thiamethoxam) control citrus leaf miners better than contact insecticides.
Fruitlets
A successful harvest depends on protecting developing fruitless, and spraying to prevent citrus canker and citrus leaf miners helps to protect immature fruit, prevent possible damage, and guarantee a plentiful supply.
Premature fruit drops can be avoided by timing spray applications properly, which also helps to maintain consistent yields and reduce needless fruit loss. Lemon fruits are extremely susceptible to water stress; insufficient moisture in the orchard causes fruitlets to fall.
Lemon Diseases
Citrus species are susceptible to over 150 pathogens and disorders caused by fungi, viruses, and a few bacterial pathogens, posing significant risks from the nursery to the bearing stage and causing substantial losses.
It’s vital to remain vigilant against common citrus diseases like citrus canker, gummosis, and root rot, as well as monitor for pests such as citrus leaf miners, lemon butterflies, and citrus leaf curls. Employing preventive measures is essential to safeguard the orchard from potential infestations and maintain crop health.
Citrus canker
Citrus canker is more common in the early stages of lemon fruit development, usually up to about 90 days after fruit set.
Caused by pathogen: Xanthomonas citri subsp. Citri.
Symptoms
- Callus-like lesions on all aerial organs
- Defoliation
- Twig dieback
- Premature fruit drop
Control measures.
- Use of copper-based bactericides like copper oxychloride.
- Keep the lemon orchard weed-free.
- Pruned out the diseased branches.
Citrus Gummosis
- Also known as Footrot.
- Pathogen: Phytophthora citrophthora (fungus)
- The development of disease is favored by wet soil and wet weather.
- Foot rot/gummosis, is a major constraint in lemon cultivation, causing significant economic loss.
- Gummosis is responsible for 10 to 30% of yield losses in citrus.
Common symptoms
- Whitish fungal dots around the bark and gummosis, later rotting of bark, and complete death of the tree.
- Infection can occur at the ground level or up the trunk of the tree.
Control
- Scratching the infected part of the stem and applying Bordeaux paste resulted in the recovery of gummosis.
- Copper oxychloride spray also reduces the disease incidence.
Root rot
Wet soil leads to root rot, and different types of fungi that are carried by the soil can be disastrous for lemon plants. Wilting, yellowing leaves, and a general decrease in vitality are the results.
Make sure the soil where your lemon tree is planted drains properly, and don’t overwater it to prevent root rot. Your strongest defenses against this terrible disease are appropriate soil drainage and good watering techniques. To keep your tree’s root system healthy, regularly check the moisture content of the tree and modify your watering schedule as necessary.
Lemon Insects
Leaf miner
Leaf minor larvae tunnel into the tissue that occurs between the top and lower leaf surfaces, they produce serpentine mines. You may see these mines as looping tracks on the leaves.
The symptoms of leaf minor mostly occur in newly formed leaves.
Control
- Use neem oil @ 5ml / liter of water and spray over the plant.
- Apply a combination of (Chloropyriphos 50% and Cypermethrin 5% EC)insecticides at a rate of 2 ml/liter of water. 2-3 Spray is needed at 15-day intervals.
Lemon butterfly
Damage Symptom
Its larvae, or caterpillars, feed on the leaves, causing holes, ragged edges, chewing marks, and skeletonized leaves, among other damage symptoms.
Control
- Collect and destroy the larva.
- Use neem oil @ 5ml / liter of water and spray over the plant.
- Apply a combination of (Chloropyriphos 50% and Cypermethrin 5% EC)insecticides at a rate of 2 ml/liter of water. 2-3 Spray is needed at 15-day intervals.
Aphids
Aphid infestations can occasionally hamper the growth of lemon trees and cause leaves to curl. Nonetheless, there are natural ways to deal with them. Aphids can be forced out of the way with a strong water spray, and if you put ladybugs or lacewings in your garden, the natural predator-prey dynamic will help keep the aphid population under control.
Aphids prefer to lurk on the undersides of leaves, so be sure to check your lemon tree frequently for signs of disease and take quick action to remove any that you detect. Aphids leave behind a sticky material called honeydew that can cause curling and cupping, especially on young growth.
Control
- Treat with strong water or apply a mild soap solution in cases of infestation.
- Introducing ladybugs or lacewings into your garden creates a natural predator-prey balance, keeping the aphid population under control.
- Use insecticides imidacloprid @ 2ml / liter water and spray.
Harvesting of Lemon
Lemon fruits become mature and ready to harvest 150 days after full bloom. Fruits are ready to harvest when the color changes from green to a bright yellow or yellow-orange. Ripe lemons should feel firm yet yield slightly to gentle pressure; avoid overly soft or hard fruits. Harvesting is generally done when the fruit reaches its optimum ripeness, ensuring the best flavor and quality.
Post-Harvesting Care
After harvesting, ongoing care for lemon trees is essential. Pruning any dead or diseased branches, fertilizing as needed, and maintaining proper irrigation contribute to the orchard’s health and prepare it for the next growing season.
What’s the best climate for my lemon tree?
Climatic zone: Subtropical to tropical
Temperature
- Best: 10°C-35°C
- New foliage damage above 40°C
- Growth of the tree is affected if temperature >50°C
Annual rainfall: 900-3000mm
Soil type
- Citrus has a shallow root system.
- Sandy, well-drained, deep soils are best for lemon tree plantation.
- Best pH: 5.5 to 7.5
Common Problem in a lemon tree and their solution?
Lemon leaves drop.
The following are the main causes of lemon leaves dropping.
1. Nutritional Deficiency
Nutritional deficiencies, particularly in essential elements like nitrogen, potassium, or magnesium, can trigger leaf drop in lemon trees. These vital nutrients play pivotal roles in various physiological processes within the tree, including photosynthesis, cell growth, and overall plant health.
When lacking these nutrients, the tree’s ability to produce chlorophyll diminishes, resulting in yellowing (chlorosis) of the leaves. Ultimately, the weakened leaves can’t sustain themselves, leading to premature shedding. Addressing these deficiencies by providing appropriate fertilizers or nutrient supplements helps restore the tree’s health and prevents further leaf drop in lemon trees.
2. Watering Issues
Watering issues significantly impact lemon trees, leading to leaf drop. Overwatering suffocates the roots, causing root rot—a fungal infection that impedes the roots’ ability to absorb water and nutrients properly. This condition stresses the tree, resulting in yellowing, wilting, and eventual leaf drop. Conversely, underwatering causes dehydration, leading to stress and subsequent leaf loss.
3. Improper Pruning
Improper pruning techniques or timing can induce leaf drop in lemon trees. Excessive or incorrect pruning causes stress to the tree, disrupting its natural growth patterns. When too much foliage is removed, the tree’s ability to photosynthesize and produce energy diminishes.
This stress prompts the tree to shed leaves as a survival response. Pruning at the wrong time, such as during the active growth period, further exacerbates leaf loss. Careful and appropriate pruning, ensuring the right amount of foliage is removed at the correct times, helps maintain the tree’s health and vitality, minimizing leaf drop in lemon trees.
4. Environmental Stress
In lemon trees, environmental stress can cause leaf drop. The system of a tree can be shocked by abrupt temperature changes, and severe weather, such as intense heat or cold, high winds, or frost. The tree’s natural physiological processes are disturbed by these pressures, and as a protective measure, it sheds its leaves.
While freezing temperatures can harm plants, high temperatures can cause excessive water loss through transpiration. Strong winds can also physically harm leaves, causing them to shed prematurely. To preserve energy and reroute resources in response to these environmental stressors, lemon trees drop their leaves, which helps them survive harsh weather.
5. Pest and Disease
Lemon trees may experience leaf loss as a result of pests and illnesses that compromise their general health. Aphids, mites, and scale insects are examples of insects that consume the sap of trees, interfering with nutrient delivery and causing stress. Additionally, they can spread illnesses like citrus greening and canker, which impairs the tree’s defenses even more.
As a result, the tree might release leaves as a kind of protection. Diseases cause yellowing, wilting, and early leaf drop in their direct target leaves. In lemon trees, leaf drops may also result from root rot brought on by a fungal infection brought on by excessive watering or inadequate drainage. This condition inhibits the uptake of water and nutrients by the roots, resulting in stress and the eventual yellowing and shedding of leaves. More leaf drops can be avoided by optimizing irrigation and drainage techniques.
6. Transplant shock
Transplant shock occurs when a lemon tree is moved to a new location or replanted, causing temporary stress that can lead to leaf drop. During transplantation, the tree undergoes disruptions to its root system, affecting its ability to uptake water and nutrients effectively.
This sudden disturbance can shock the tree, prompting it to shed leaves as it acclimates to its new environment. The stress from the transplantation process affects the tree’s overall health, temporarily compromising its ability to support its foliage. Given time to adjust and proper care post-transplantation, the tree can recover from this shock, reducing further leaf drop in lemon trees.
7. Natural Cycle
Some leaf drop is a normal part of a lemon tree’s growth cycle. It sheds older leaves to make room for new growth, especially in response to seasonal changes.
Control of leaves drop
- To prevent leaves from dropping, only water lemon trees when the first 2-4 inches of soil gets dry and avoid temperatures below 32ºF.
- Feed the plant with proper nutrition.
- Maintain a proper drainage system.
Lemon fruits crack
Lemon fruit cracks because of the following reasons.
- Irregular irrigation
Irregular water supply after a long drought period leads to sudden expansion of the fruit interior and causes the fruit peel to crack.
2. Uneven fertilizer application
Lack of Ca, B, K, and Zn during the fruit cell enlargement stage may cause fruit cracking.
3. Hot, dry, and Windy days
In hot, dry, and windy weather, fruit surfaces quickly lose water, making the peel relatively rigid. The fruit absorbs a significant amount of water from subsequent irrigation or rainfall, which causes the rind to burst at its most vulnerable point.
Control of fruit crack
Fruit splitting can be prevented by lowering the physiological stress on a citrus tree, which can be achieved by:
- Water a citrus tree regularly, making sure it never becomes too dry.
- Appropriate feeding involves making sure the tree gets the nutrients it needs from a balanced fertilizer that provides all the macronutrients and necessary micronutrients.
- Crop load can be decreased with the right pruning.
- Better calcium supply, through soil and foliar applications during summer, also minimizes risks.
Lemon fruits drop?
Lemon fruit drops due to the following reasons:
- Fruits having less number of seed drop early.
- Plants with less number of leaves induce fruit drop.
- High temperature and low relative humidity cause fruit drop.
- Water stress during the fruit-growing period also led to fruit drops.
- An overload of fruit induces a drop of young fruits.
- Diseased fruit drops prematurely.
- Insect infestations like leaf miners and lemon butterflies may also cause fruit drop.
Control lemon fruit drops.
- Keep proper moisture during the fruit growing period.
- Provide sufficient nutrients. Spray ZnSo4 during the early fruit development stage.
- Prevent the plant from citrus canker disease, lemon leaf miner, and lemon butterfly to reduce the drop.
FAQs
Q1. What is the powder on my lemon tree leaves?
Powdery mildew, a fungal disease commonly found in citrus plants, is most likely the powdery stuff on the leaves of your lemon tree. It is found on the leaf surface as a white or grayish powder, frequently accompanied by curling or yellowing of the foliage.
Warm, humid environments are ideal for powdery mildew growth, which can spread quickly if left untreated. It can be controlled by pruning the afflicted branches, increasing airflow around the tree, and using sulfur and copper-based fungicide sprays on citrus trees. Powdery mildew outbreaks can also be avoided by performing routine maintenance and maintaining the health of the tree with appropriate fertilizer and watering.
Q2. What is the fungal disease on my lemon tree?
Phytophthora spp. and Diplodia spp. are two of the pathogens that cause citrus gummosis, a fungal disease. Gummy exudates from lesions on citrus trees’ trunks and branches eventually leak out as a result. Bark cracking and cankers are often the result of these lesions, which appear black and sunken.
If citrus gummosis is not treated, it weakens the affected tree and prevents it from absorbing water and nutrients, which can eventually cause the tree to die back or die altogether. Among the management techniques include stem pasting with Bordeaux paste fungicide, branch cutting, and drainage improvement. Planting citrus types resistant to disease and maintaining proper orchard sanitation are key components of prevention.
Q3. How do you clean a lemon tree?
To start cleaning your lemon tree, remove any fallen fruit, dead leaves, or debris from around the base of the tree. Next, use sharp, sterilized pruning shears to carefully cut off any diseased or dead branches. Make a concentration by combining ½ cup of detergent with two cups of olive oil. Use a liter of water to dilute one teaspoon of this solution, then spray over the leaves.
Moreover, being careful not to damage the bark, carefully wipe the remaining branches with a damp cloth to remove accumulated dust and debris. Finally, to support the tree’s health and vitality, make sure it gets the right amount of fertilizer and irrigation. The robustness and production of the lemon tree depend on regular maintenance, which includes cleaning and trimming. In addition,
