Contents
Key Facts
- Meyer lemons: Meyer lemons, which are a cross between an orange and a lemon, can turn from bright yellow to a dull orange if they are left on the tree too long and not picked at their peak.
- Orange Meyer lemons: Some Meyer lemon trees can produce orange fruit. These oranges Meyer lemons may be a result of the fruit being left on the tree for too long or due to other factors.
- Rootstock influence: In some cases, the rootstock of a lemon tree can influence the color and taste of the fruit. For example, if a Meyer lemon tree experiences damage or a freeze, the rootstock may emerge and produce different types of fruit, such as sweet, thick-skinned orange fruits or smaller tart/sweet orange fruits.
The Natural Variation of Lemon Colors
Lemons typically exhibit a range of yellow and green shades, including lemon yellow, lemon chiffon, lemon meringue, lemon glacier, bitter lemon, citron, and lemon curry. However, naturally occurring orange-colored lemons are also known to exist.
The coloration of lemons is determined by the presence of different pigments within the fruit. The specific pigments responsible for the yellow and green shades of lemons have not been identified in the available literature. Nonetheless, the natural variation in lemon colors is a testament to the diverse array of pigments and compounds found in citrus fruits.
Factors Affecting Lemon Color
- Genetic factors: Different lemon varieties have distinct genetic predispositions that influence their natural color variations, ranging from pale yellow to bright yellow.
- Environmental conditions:
- Temperature fluctuations, especially during ripening, can affect lemon color. Lower temperatures can inhibit chlorophyll production, leading to increased carotenoid production and a yellow or orange color.
- Sunlight exposure enhances carotenoid production, contributing to a deeper yellow color.
- Soil composition and nutrient availability:
- Adequate nitrogen is crucial for chlorophyll production and green color development.
- Imbalances in soil nutrients can impact the overall health and color of lemons.
The Influence of Ripeness on Lemon Color
- Ripening process in lemons:
- Meyer lemons ripen from November to April.
- The fruit changes color as it ripens.
- Meyer lemons are sweeter than conventional lemons and can remain on the tree for an extended harvesting period.
- Color changes in ripening lemons:
- Lemons start green and turn yellow as they ripen.
- Meyer lemons may develop a greenish hue with a tinge of yellow or an egg-yolk color when ripe.
- Most lemons continue to ripen and turn yellow even if they appear greenish.
- Ripeness and development of orange hues:
- As lemons ripen, they develop orange hues, particularly in the peel.
- Carotenoid pigments contribute to the development of orange hues.
- Carotenoids are synthesized in the fruit of many citrus species during ripening.
Citrus Diseases and Disorders
- Overview of Citrus Diseases:
- Several diseases can cause color changes in lemons, including bacterial blast, botrytis rot, anthracnose, citrus canker, and citrus greening.
- Specific Disorders:
- Citrus greening (Huanglongbing) is a bacterial disease that causes mottling and yellowing of leaves, stunted growth, fruit drop, and abnormal fruit development.
- Phytophthora root rot is a fungal disease that can lead to pale green to yellowish leaves and decline in tree growth.
- Symptoms and Effects on Lemon Coloration:
- Symptoms of citrus diseases and disorders include leaf discoloration, premature leaf drop, twig dieback, and fruit abnormalities.
- Citrus greening is characterized by yellowing that crosses leaf veins.
- Phytophthora root rot can cause pale green to yellowish leaves.
Cultural Practices and Color Changes
- Impact of cultural practices:
- Pruning and fertilization can influence lemon color.
- Pruning improves air circulation and light penetration, leading to better color development.
- Adequate nitrogen enhances the green color of lemons.
- Effects of pesticide use:
- Pesticides can affect lemon pigmentation if not used properly.
- Follow proper application guidelines to minimize discoloration or blemishes.
- Post-harvest treatments and their influence:
- Waxing or coating lemons helps preserve color and prevent moisture loss.
- Storage conditions (temperature and humidity) impact lemon color during the post-harvest period.
Conclusion
The color change of Meyer lemons from yellow to orange can occur due to various factors. This includes the lemons being left on the tree for too long, resulting in a dull orange hue. Additionally, certain Meyer lemon trees may naturally produce orange fruit. Furthermore, the rootstock of the lemon tree can play a role in influencing the color and taste of the fruit, often producing different types of orange fruits. Understanding these factors can help us appreciate the unique characteristics and variations in Meyer lemons.
Sources:
https://www.reviewjournal.com/life/home-and-garden/expert-sheds-light-on-orange-lemons/
https://www.houzz.com/discussions/3591437/orange-meyer-lemons
https://gardening.stackexchange.com/questions/56586/why-is-my-meyer-lemon-producing-orange-fruit
FAQs
Why are my lemons orange instead of yellow?
Lemons can turn orange due to factors such as genetics, environmental conditions, soil composition, nutrient availability, ripeness, citrus diseases, cultural practices, pesticide use, and post-harvest treatments.
What causes lemons to turn orange when they are ripe?
As lemons ripen, they develop orange hues due to the presence of carotenoid pigments, which are synthesized during the ripening process.
Can orange lemons be eaten?
Yes, orange lemons are safe to eat and have a similar nutritional value to yellow lemons.
How can I prevent my lemons from turning orange?
To minimize the chances of lemons turning orange, ensure proper cultural practices, such as pruning and fertilization, avoid excessive pesticide use, and maintain optimal storage conditions.
Are orange lemons a different variety of lemon?
While some lemon varieties are naturally more orange in color, orange lemons can also result from environmental factors and ripening processes.