Understanding the Water Needs of Lemon and Citrus Trees
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Comprehensive Guide to Lemon Tree Watering and Irrigation Systems
Lemon trees are one of the most popular citrus trees globally, widely cultivated in regions with warm climates. As evergreens that may have more than one production per year (polyphorous), lemon trees need watering almost all year long. Despite their relative drought tolerance, water management is crucial for optimizing lemon orchard productivity and fruit quality (and juice concentration). To plan a suitable irrigation schedule, the grower needs to take into account many different factors. The most important ones are the type of soil, the environmental conditions (rainfalls, temperature, etc.), the age of the trees and the variety and rootstock, the expected production, and the availability of water. Three-quarters of citrus tree roots are located in the upper 45-60 cm (1.47-2 feet) of the soil. However, this may vary depending on the selected rootstock and the soil. Shallow-rooted trees are more prone to water stress, and farmers should take all necessary measures to avoid this.
Water Requirements of Lemon Trees in the Different Growth Stages
Like other citrus trees, lemon trees have varying water needs at different growth stages. A clear understanding of these stages helps farmers manage water more efficiently and support his/her crops to become vigorous and produce fruits of great quality.
Young trees: Young trees need frequent and shallow irrigation to encourage root growth. This stage is critical, as a strong root system supports the tree’s development over its lifetime.
Maturity-Productive trees: As trees reach maturity, their water requirements stabilize. Mature lemon trees still require proper irrigation to maintain fruit size, quality, and yield consistency. They can use between 800 and 1500 mm of water annually.
Seasonal Irrigation Plan for Lemon Orchards
For creating the irrigation schedule for a growing season (1 year), the farmer is advised to combine 2 strategies:
- The plant-based scheduling: this includes knowledge of plant growth stages and visual assessment of the plant.
- The soil-based scheduling: this includes the use of soil sensors
Spring
During this period, trees grow new shoots and leaves. Adequate water is essential to support this vegetative expansion. Additionally, in mid-to-late spring, we also have flowering and fruiting. This phase demands precise water management. It’s crucial to ensure uniform moisture without causing waterlogging. Water deficits can lead to flower drops and reduced fruit set, while over-irrigation can harm fruit quality.
Depending on the environmental conditions, one irrigation, with 30-40 liters or 8-10.5 gallons/tree for young trees and 80-120 liters or 21-31.7 gallons/mature tree, might be needed every 3-5 days for young trees and 5-7 days for mature trees.
Summer
During this period, we have the fruit setting and the growth of the lemons. At the same time, these months are usually the warmest and driest of the year. High temperatures lead to increased evapotranspiration. Efficient water application is vital to prevent drought stress that can compromise fruit size. As a result, mitigating heat stress and maintaining fruit development are our top priorities, and irrigation should be adjusted accordingly.
During summer, the irrigation frequency increases with approximately one irrigation every 2-3 days for young trees and every 3-5 days for mature trees. Young trees may need 40-50 liters or 10.5-13.4 gallons per application, while mature trees require 120-160 liters (31.7-42.3 gallons), depending on temperatures.
Autumn
For most lemon varieties, autumn is the month when fruit maturity and harvest occur. For this reason, the priority is to maintain soil moisture to facilitate final fruit growth and ripening. In this case, the irrigation sessions are less frequent, happening once a week or once every 10 days, with approximately 30-40 liters or 8-10.5 gallons for young trees and 80-100 liters or 21-31.7 gallons for mature trees.
Winter
During winter, the lemon trees enter the dormancy phase (less water requirements) and the temperature drops. In most cases, rainfall is sufficient to support the needs of the trees. In especially drought winters, 1 irrigation every 2-4 weeks might be needed, with 30-50 liters or 8-13.4 gallons per mature tree. It is important not to stress the trees because this may have a negative effect in the next season. Over-irrigation and water-logging should be avoided to reduce the risk of root rots and frost damage of the root system.
Irrigation Systems for Lemon Orchards
Selecting an appropriate irrigation system is crucial for maintaining lemon orchards’ productivity and sustainability. Different systems offer unique benefits and challenges depending on the orchard’s size, topography, and water resources. The key to successful water management in a lemon orchard is choosing a system that balances efficiency, cost, and ease of maintenance.
Drip irrigation is by far the most recommended and widely adopted system for irrigation of a lemon orchard. It involves delivering water directly to the root zone through a network of pipes and emitters. The primary advantage of this method is its efficiency, achieving up to 90-95% water-use efficiency by minimizing evaporation and runoff. Drip irrigation allows farmers to precisely control the volume and frequency of water application, reducing the risks of both over-irrigation and under-watering. Additionally, keeping the tree foliage dry helps prevent fungal infections and leaf diseases, which are common issues in humid conditions. However, while drip irrigation is effective, its initial installation costs can be high. Farmers also need to be cautious of emitter clogging, which can occur if the water quality isn’t closely monitored.
Micro-sprinkler irrigation is another popular system that uses low-pressure devices to spray water over a small area around the base of the tree. This method offers better soil coverage than traditional sprinklers and helps keep a larger portion of the root zone moist, encouraging more extensive root development. However, while micro-sprinklers improve root zone moisture, they have slightly higher evaporation losses than drip irrigation. Additionally, these systems require more maintenance to ensure the emitters and spray heads remain functional.
A traditional irrigation method still in use is flood or basin irrigation, where shallow basins are created around each tree, which are then flooded with water. The key advantages of this method are its low installation cost and simplicity of setup. It’s particularly suitable for farmers with limited investment capabilities or regions with an ample water supply. However, basin irrigation is less efficient than modern systems like drip or micro-sprinklers, as it involves significant water losses due to evaporation and deep percolation. This method can also increase the risk of waterlogging and root diseases, particularly in heavier soils.
Another traditional method is furrow irrigation, which involves channeling water between rows of trees through small trenches or furrows. While furrow irrigation is relatively inexpensive to implement and can work well on sloped terrains, it often leads to high evaporation and runoff losses. Additionally, achieving uniform water distribution across all rows can be challenging, potentially affecting the growth and yield consistency in the orchard.
Conclusion
Water management is crucial for achieving high yields and quality fruit in lemon orchards. Different growth stages and seasons require varied irrigation strategies to balance tree health, productivity, and resource efficiency. Drip irrigation, with its precise application, remains the best option for most lemon orchards, offering improved water-use efficiency and minimal disease risks. However, understanding the pros and cons of each irrigation system allows growers to choose the most suitable approach for their specific conditions. Efficient water management and the right irrigation system ensure that lemon trees receive the right amount of water at each growth stage. This practice conserves precious water resources and improves the quality and yield of lemon crops.
References
- NSW Department of Primary Industries – “Lemon Irrigation Guidelines”
- National Horticulture Board (NHB) of India – “Citrus Cultivation Guidelines”
- University of California IPM – “Cultural Tips for Citrus Watering”
- Arizona Cooperative Extension – “Irrigating Citrus Trees in Arizona”
- University of California Agriculture and Natural Resources – “Citrus Production Manual”
- Department of Primary Industries and Regional Development, Western Australia – “Citrus Irrigation Recommendations”
- ResearchGate – “Effects of Drip Irrigation Design on Lemon Orchards in Semi-Arid Conditions”
- International Society for Horticultural Science (Acta Horticulturae) – “Irrigation Requirements of Citrus”
- ScienceDirect – “Citrus Water Relations and Irrigation Requirements”
- University of Florida IFAS Extension – “Citrus Irrigation Management”
- Cambridge University Press – “Water Relations and Irrigation Requirements of Citrus”
- NSW Department of Primary Industries – “Managing Citrus Orchards with Less Water”
- University of Florida IFAS Extension – “Citrus Irrigation Scheduling”
Further reading
15 Interesting Facts about Lemon Trees
Information, Uses, Health Benefits, and Nutritional Value of Lemons
The most Popular Lemon Tree Varieties
How to Cultivate Lemon Trees Commercially
Site Selection and Soil Preparation for Planting a Lemon Orchard
Complete Guide to Planting Lemon Trees
Lemon Tree Propagation and Pollination
Lemon Tree Pruning for Optimal Growth and Yield
Understanding the Water Needs of Lemon and Citrus Trees
Nutrient needs and Fertilization of Lemon trees
Pest and Weed Management in Lemon Orchards
Important Virus Diseases in Citrus trees
Important Citrus Diseases caused by Fungi
