Lemon Tree Yield, Harvest, and Storage

Maximizing Lemon Yields: Harvesting, Handling, and Storage Tips for Lemon Growers

Lemon is a popular citrus fruit cultivated in subtropical and tropical regions for its distinctive flavor and health benefits. To achieve optimal yields, quality, and, ultimately, maximum sales prices, lemon growers must understand the entire cycle of lemon production, from assessing yields to post-harvest handling and storage.

How much does a lemon tree yield? - Maximizing Lemon Tree Yields

Lemon tree yields depend on several factors, including the local environmental conditions, soil quality, water and nutrient availability, and successful pest management. Young lemon trees typically start producing fruit by their third-fourth year and reach maximum productivity at 8-15 years old. Mature trees can yield up to 85-150 kg (190-330 lb) per tree annually, though trees in optimal conditions can surpass these figures. Eureka and Lisbon lemons are among the most commercially cultivated varieties and offer consistent yearly yields, whereas some cultivars might have specific peak seasons.

When and How to Harvest Lemons

The time between flowering and harvest for lemons can vary from 4 to 12 months (6-9 months is more common), influenced by factors such as the variety, fruit load, temperature, farming practices applied, desired ripeness, and intended market. Lemons that are grown in tropical (warmer and humid) climates generally develop larger, juicier fruit with higher acidity and peel oil content than those from Mediterranean regions (dry climate), where the drier conditions tend to produce a slightly different fruit profile.

Unlike some fruits, lemons do not ripen after harvest, so they must be picked when fully mature to ensure the best quality. Maturity is usually determined by color, size, and juice content. Lemons are typically picked when they are 4-7.5 cm (1.5 to 2 inches) in diameter (of course, that may vary depending on the variety) and then cured, allowing the peel to smooth and turn yellow while juice content increases. This curing is done by storing the green fruit at room temperature. A pale yellow hue is ideal for lemons to be harvested for longer storage or export since the fruits are less likely to be damaged or spoiled upon reaching their destination or the end buyer.

Lemons are usually harvested manually. To harvest them effectively, you need to:

Choose the right season for harvesting, typically from winter through early spring in subtropical regions
Hand-pick carefully to avoid bruising or puncturing the fruit.
Use snips or clippers to cut the stem close to the fruit, preventing skin damage.
Use clean picking bags (up to 25 kg or 55 lbs capacity).

Post-Harvest Handling of Lemons

After harvest, lemons undergo a series of handling steps designed to maintain quality and reduce spoilage:

Washing and Disinfection: Lemons are washed to remove field contaminants (dust, insects, etc) and disinfected to kill microorganisms on the skin. This step minimizes the risk of post-harvest diseases and damages, helping maintain the quality and safety of the product during storage or transport.

Waxing: A light wax coating is applied to retain moisture and improve the appearance of the fruit (the glossy appearance is more appealing to consumers). Waxing also provides a protective layer, which is beneficial for long-distance transport.

Sorting and Grading: Lemons are graded based on color, size, shape, and quality. Common defects like blemishes or irregular shapes can affect marketability. Typically, a high-quality lemon will have a bright yellow color, be firm to the touch, and contain a substantial amount of juice.

Grade 1 lemons are uniformly yellow with smooth skins, free from significant blemishes.
Grade 2 lemons may have minor imperfections but still meet size and juice standards.
Lower Grades often include lemons with surface blemishes, which are sold at reduced prices or processed into juice products.

Grading is crucial, especially for export markets, where retailers and consumers expect consistent quality. Grading also helps in pricing, as higher-grade lemons command better prices in domestic and international markets.

Storing Lemons

Once harvested, lemons must be stored correctly to extend their shelf life. Ideal storage conditions are temperatures between 10-15°C (50-59°F) and relative humidity around 85-90%. Controlled temperature and humidity help prevent moisture loss and slow aging. Lemons should not be stored below 7°C (44.6°F), as these conditions can cause chilling injury, resulting in brownish lesions on the skin and reduced quality.

In refrigerated storage, lemons can last four to six weeks, but they can be preserved for up to 3 to 6 months in optimal conditions. Growers and distributors often use modified atmospheric storage to reduce respiration rates, thus extending freshness. Proper ventilation is essential to avoid the accumulation of ethylene gas, which can cause premature aging.

Packaging (Packaging Options for Lemons):

Packaging is critical in protecting lemons during transportation and storage. Lemons are typically packed in boxes or crates (sacks, bags, bamboo baskets, etc.) that provide ample ventilation (or/and use breathable materials), reducing the buildup of ethylene gas and moisture and limiting the risk of decay and mold growth. The fruits intended for export are often cushioned with paper or foam to reduce bruising. Many growers and exporters are transitioning to eco-friendly packaging solutions, using recycled materials to reduce environmental impact.

Lemons may also be packed individually for premium markets. In such cases, the fruit is often wrapped in tissue paper or placed in molded trays to ensure that each lemon is protected from abrasions and other potential damage during transport.

Summary

Achieving optimal yields and high-quality lemon production requires careful attention to every stage, from pre-harvest care through post-harvest handling. Proper lemon management, knowledge of the quality factors, and export standards allow growers to deliver fresh, high-quality lemons that meet market demands for both quality and sustainability while minimizing waste.

References

https://edis.ifas.ufl.edu/publication/HS402

https://pdf.usaid.gov/pdf_docs/pnacy845.pdf

https://californiaagriculture.org/api/v1/articles/114495-nuclear-lines-of-citrus-tree-size-yield-and-fruit-characters-of-old-and-young-lines-of-ten-citrus-varieties-compared.pdf

https://www.sciencedirect.com/science/article/abs/pii/S0304423802001218

https://coststudyfiles.ucdavis.edu/uploads/cs_public/57/c4/57c4611c-f2bb-4bde-9b77-a343ca9f0a62/lemonvs10.pdf

https://agriculture.az.gov/sites/default/files/Harvest%20Calendar.pdf

https://minnetonkaorchards.com/right-time-to-pick-lemons/

https://www.freshplaza.com/europe/article/9673300/optimal-fruit-ripening-to-secure-markets/

https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=55912#:~:text=The%20only%20way%20to%20determine,peaches%20and%20some%20other%20fruits.

https://www.abc.net.au/gardening/harvesting-citrus/102657304

https://aggie-hort.tamu.edu/patiocitrus/harvesting.html