Cultivation:

Influence of Climate Factors on Clementine and Tangerine Cultivation

Acidity

The level of acid present in a substance, such as fruit juice.

Air temperature

The measure of how hot or cold the air is in a specific location.

Breeding programs

Programs that aim to create new plant varieties with desired traits through controlled crossbreeding.

Clementines

A type of citrus fruit that is smaller and sweeter than regular oranges.

Commercial acceptance

The degree to which a product is accepted and desired by consumers in the market.

Cultivar

A cultivated variety of a plant that has been selected and maintained by humans.

Hybrids

Offspring resulting from the crossbreeding of two different species or varieties.

Mandarins

A group of citrus fruits that includes clementines and tangerines.

Mediterranean climate

A climate characterized by hot, dry summers and mild, humid winters, typically found in regions bordering the Mediterranean Sea.

Organoleptic quality

The sensory characteristics of a food or beverage, including taste, aroma, texture, and appearance.

Peel color

The color of the outer skin or rind of a fruit.

Relative air humidity

The amount of moisture present in the air compared to the maximum amount it can hold at a given temperature.

Respiratory activity

The process by which living organisms take in oxygen and release carbon dioxide.

Soluble solids

Substances that can dissolve in a liquid, such as sugars and other compounds found in fruit.

Tangelos

Hybrids created by crossing mandarin trees with grapefruit trees, typically more adapted to tropical climates.

Tangerines

A type of citrus fruit that is similar to oranges but smaller and easier to peel.

Thermal amplitude

The difference in temperature between the highest and lowest points during a specific day.

Thermal variation

The difference in temperature between the highest and lowest points during a specific time period.

The optimal growing conditions for clementines and tangerines are influenced by various climate factors such as air temperature, relative air humidity, and thermal variation throughout the day. In tropical regions with high and constant average temperatures, the quality of the fruit is often compromised. This is due to the high respiratory activity of the fruits, which results in a lower concentration of soluble solids and acidity.ref.42.8 ref.42.8 ref.7.152 Consequently, the fruit quality is not as desirable in these regions. In contrast, regions with a Mediterranean climate, characterized by hot and dry summers and mild humid winters, provide more favorable conditions for clementine and tangerine cultivation. Fruits grown in these regions are of higher quality and have greater commercial acceptance.ref.7.152 ref.7.152 ref.42.8

The intensity of fruit peel color, which is an important quality characteristic, is regulated by air temperature and daily thermal amplitude. When mandarins are produced under temperatures above 30 ºC, their quality tends to deteriorate. To overcome these limitations and improve fruit quality, breeding programs often employ strategies such as crosses between different species.ref.25.23 ref.25.447 ref.7.152 By crossing mandarin trees, such as 'Clementina', with grapefruit trees, hybrids called tangelos are created. These hybrids are usually more adapted to tropical climates and exhibit improved fruit quality.ref.7.60 ref.7.152 ref.7.152

To further enhance fruit quality and overcome temperature limitations, a recent cultivar called 'Tango' mandarin has been developed. This cultivar produces seedless mandarins of high organoleptic quality and has gained popularity worldwide. It is mainly grown in Andalusia, Spain, and its harvest season typically begins at the end of December and may continue until the end of February.ref.7.122 ref.7.152 ref.7.152 However, the optimal time to harvest 'Tango' mandarins and their sensitivity to low temperatures are still under investigation.ref.7.122 ref.7.16 ref.7.152

Clementines are believed to have originated in the subtropical and tropical areas of Asia, particularly in parts of Southeast Asia including China, India, and the Malay Archipelago. The first documented reference to citrus fruits, including mandarins and pummelos, was during the reign of Ta Yu in China between 2205 and 2197 BC. The cultivation of citrus fruits spread to northern Africa and southern Europe towards the end of the first millennium, introduced by the Arabs.ref.39.24 ref.39.24 ref.15.22 The first crops of citrus fruits appeared in Florida around 1655 and in California around 1769.ref.39.24 ref.39.25 ref.15.23

However, the specific origin and cultivation of clementines are not mentioned in the provided document excerpts.

Harvesting Practices for Clementines and Tangerines

The best practices for harvesting clementines and tangerines depend on the specific cultivar and the desired fruit quality. For instance, clementines like the 'Clemenules' variety, which are considered early mandarins, are typically harvested from early September to late December. At the beginning of the season, these clementines are often treated with degreening ethylene to enhance their external color.ref.7.152 ref.7.16 ref.7.97

On the other hand, tangerines such as the 'Tango' cultivar are mid-late season maturing varieties and are harvested from the end of December to the end of February. However, the optimal time to harvest 'Tango' mandarins and the changes in fruit quality during this period are still under study. Conducting further research to study the specific characteristics of each cultivar is crucial in determining the optimal harvest time and ensuring high-quality fruit.ref.7.122 ref.7.152 ref.7.152

It's important to note that the choice of rootstock onto which the mandarin cultivar is grafted can also influence the harvest time and fruit quality. The rootstock plays a vital role in maintaining acidity and sugar contents throughout the harvest and affecting external coloration. In Spain, the most commonly used rootstock is Carrizo Citrange (CC), which is known for its tolerance to citrus tristeza virus.ref.7.122 ref.7.231 ref.7.97 However, it may also present problems such as iron chlorosis and salinity.ref.7.231 ref.7.97 ref.7.228

Determining the optimal harvest time for clementines and tangerines depends on several factors, including the cultivar and desired fruit quality. In the case of early mandarins in the Mediterranean Region, fruit can be harvested at the beginning of the season, even before full external coloration, and then subjected to ethylene degreening treatment to enhance the external color. Ethylene treatment accelerates chlorophyll degradation and carotenoid biosynthesis, resulting in improved external color.ref.7.97 ref.7.97 ref.7.16 However, the time required to achieve the desired color of the fruit depends on the initial fruit color, and prolonged exposure to ethylene can make the fruit more susceptible to senescence alterations.ref.25.23 ref.7.97 ref.25.438

As for the potential drawbacks or risks associated with degreening ethylene treatment, the longer the exposure time, the more susceptible citrus fruit is to senescence alterations. Additionally, post-treatment storage time can accentuate the incidence of disorders like calyx senescence, especially when fruit is exported to distant countries with strict cold-quarantine treatments. However, degreened fruit intended for the European Union market has a lower risk of developing disorders compared to fruit exported to countries like the USA or Japan.ref.25.438 ref.25.437 ref.25.227

The use of Carrizo Citrange rootstock may lead to potential problems of iron chlorosis and salinity. Iron chlorosis refers to the condition where the leaves of the citrus tree turn yellow due to iron deficiency, and salinity refers to the presence of excessive salts in the soil, which can negatively affect plant growth. However, there are alternative rootstocks available that can mitigate these issues while still providing tolerance to citrus tristeza virus.ref.7.232 ref.7.49 ref.7.36

Propagation Methods in Clementine and Tangerine Cultivation

In clementine and tangerine cultivation, two primary propagation methods are commonly used: grafting and seed propagation. Grafting involves the process of attaching the scion, which is the fruiting cultivar, onto a second citrus cultivar known as the rootstock. The rootstock serves as the lower trunk and root system of the grafted plant.ref.11.15 ref.11.15 ref.11.16 It is important to note that rootstocks used in citrus cultivation are specifically selected or created for their suitability as rootstocks.ref.7.122 ref.11.15 ref.11.16

In addition to grafting, induced mutagenesis has been employed to obtain new citrus cultivars. One common method used is gamma irradiation, which allows for the modification of specific traits while preserving the main genetic background of the initial cultivar. Sexual breeding is another propagation method utilized in citrus cultivation, with most citrus and related genera exhibiting diploidy.ref.15.36 ref.12.43 ref.11.31

Alternaria brown spot (ABS)

A disease that affects citrus orchards, particularly susceptible cultivars like 'Fortune' mandarin.

Antimicrobial peptides (AMPs)

Peptides that have antimicrobial properties and can be expressed in plants to confer resistance against bacterial infections.

Asian citrus psyllid

A significant vector of diseases like citrus greening in citrus orchards.

Candidatus Liberibacter asiaticus

The bacterium that causes citrus greening disease.

Citrus greening

A devastating disease in the citrus industry caused by Candidatus Liberibacter asiaticus and transmitted by the Asian citrus psyllid.

Controlled release fertilizers

Fertilizers that slowly release nutrients over an extended period of time, improving plant growth and nutrient availability.

Degreening ethylene treatment

A treatment applied to enhance external coloration of fruits during the harvesting process.

Grafting

A propagation method commonly used in citrus orchards where a scion (desired variety) is attached to a rootstock.

Induced mutagenesis

A breeding technique that induces mutations in plants to create new varieties.

Integrated pest management

A holistic approach to pest management that includes regular monitoring, early detection, and a combination of strategies for effective pest and disease management in citrus orchards.

Polymerase chain reaction (PCR)

A laboratory technique used to amplify a specific DNA sequence, often used for the detection of Candidatus Liberibacter asiaticus.

Precision management practices

Specific and targeted management practices, such as the application of balanced fertilizers, herbicides, and pesticides, for sustainable citrus production.

Quantitative real-time PCR (qPCR)

A variation of PCR that allows for the quantification of DNA, often used for the detection of Candidatus Liberibacter asiaticus.

Seed propagation

A propagation method where citrus trees are grown from seeds.

Septoria spot

A fungal disease caused by Septoria citri that affects citrus orchards, particularly in Italy.

Sexual breeding

A breeding technique that involves the crossing of two parent plants to create new varieties.

Alternaria brown spot (ABS)

A disease that affects citrus orchards, particularly susceptible cultivars like 'Fortune' mandarin.

Antimicrobial peptides (AMPs)

Peptides that have antimicrobial properties and can be expressed in plants to confer resistance against bacterial infections.

Asian citrus psyllid

A significant vector of diseases like citrus greening in citrus orchards.

Candidatus Liberibacter asiaticus

The bacterium that causes citrus greening disease.

Citrus greening

A devastating disease in the citrus industry caused by Candidatus Liberibacter asiaticus and transmitted by the Asian citrus psyllid.

Controlled release fertilizers

Fertilizers that slowly release nutrients over an extended period of time, improving plant growth and nutrient availability.

Degreening ethylene treatment

A treatment applied to enhance external coloration of fruits during the harvesting process.

Grafting

A propagation method commonly used in citrus orchards where a scion (desired variety) is attached to a rootstock.

Induced mutagenesis

A breeding technique that induces mutations in plants to create new varieties.

Integrated pest management

A holistic approach to pest management that includes regular monitoring, early detection, and a combination of strategies for effective pest and disease management in citrus orchards.

Polymerase chain reaction (PCR)

A laboratory technique used to amplify a specific DNA sequence, often used for the detection of Candidatus Liberibacter asiaticus.

Precision management practices

Specific and targeted management practices, such as the application of balanced fertilizers, herbicides, and pesticides, for sustainable citrus production.

Quantitative real-time PCR (qPCR)

A variation of PCR that allows for the quantification of DNA, often used for the detection of Candidatus Liberibacter asiaticus.

Seed propagation

A propagation method where citrus trees are grown from seeds.

Septoria spot

A fungal disease caused by Septoria citri that affects citrus orchards, particularly in Italy.

Sexual breeding

A breeding technique that involves the crossing of two parent plants to create new varieties.

Pest and Disease Management in Clementine and Tangerine Orchards

Effective pest and disease management is crucial for ensuring the health and productivity of clementine and tangerine orchards. Several strategies can be employed to manage pests and diseases in these orchards. One approach involves the use of controlled release fertilizers, which have been shown to improve plant growth and nutrient availability.ref.11.29 ref.54.100 ref.11.29 Precision management practices such as the application of balanced fertilizers, herbicides, and pesticides are also necessary for sustainable citrus production.ref.54.100 ref.54.99 ref.11.29

The citrus industry faces constant threats from various bacterial, fungal, and viral infections. One particularly devastating disease is citrus greening, which is caused by Candidatus Liberibacter asiaticus. This disease has had a significant impact on the industry and is transmitted by the Asian citrus psyllid (Diaphorina citri).ref.15.27 ref.54.60 ref.54.246 Polymerase chain reaction (PCR) and quantitative real-time PCR (qPCR) can be used for the detection of Candidatus Liberibacter asiaticus.ref.54.276 ref.54.276 ref.15.27

Another disease that affects citrus orchards is Alternaria brown spot (ABS), which particularly affects susceptible cultivars like 'Fortune' mandarin. Control measures for ABS typically involve the application of fungicides, with the frequency depending on the climate and cultivar susceptibility. However, the systematic use of fungicides may have environmental and health concerns.ref.15.27 ref.12.37 ref.15.27 Certain citrus genotypes, such as 'clementine', 'Willowleaf', and 'satsuma' mandarins, have exhibited resistance to ABS.ref.15.159 ref.15.160 ref.12.37

Septoria spot, caused by Septoria citri, is another fungal disease that affects citrus orchards, with Italy being one of the affected countries. This disease can cause leaf spots and stem cankers, leading to production losses. Preventive measures for fungal diseases like Septoria spot include selecting suitable plantation sites, surface leveling of the ground to avoid waterlogging, soil drainage, and rational irrigation management.ref.19.4 ref.19.1 ref.19.15 Localized irrigation methods, such as drippers, are generally less conducive to leaf and fruit diseases.ref.19.3 ref.19.15 ref.19.1

In terms of pest management, the Asian citrus psyllid is a significant vector of diseases like citrus greening. While aggressive agrochemical treatments are commonly used to control pests, they may not provide a lasting and sustainable solution. Biotechnological approaches, such as the expression of antimicrobial peptides (AMPs) or genes inducing plant defense mechanisms, have shown promise in conferring resistance against bacterial infections.ref.54.276 ref.54.279 ref.54.99

It is important to note that the strategies and approaches for pest and disease management may vary depending on the specific region and circumstances. Integrated pest management practices, including regular monitoring and early detection, are crucial for effective pest and disease management in citrus orchards.ref.54.99 ref.54.247 ref.54.181

The document excerpts do not provide specific information about the kinds of mold that clementine and citrus fruits are susceptible to.

In conclusion, the cultivation of clementines and tangerines is influenced by various climate factors such as air temperature, relative air humidity, and thermal variation throughout the day. The optimal growing conditions vary depending on the region and climate, with tropical regions often experiencing lower fruit quality due to high respiratory activity. Harvesting practices depend on the specific cultivar and desired fruit quality, with degreening ethylene treatment being applied to enhance external coloration.ref.42.8 ref.42.8 ref.7.97 Propagation methods commonly used include grafting and seed propagation, with induced mutagenesis and sexual breeding also being employed. Pest and disease management in clementine and tangerine orchards require a combination of strategies such as the use of controlled release fertilizers, precision management practices, and the application of appropriate fungicides and pesticides. Integrated pest management practices are crucial for effective pest and disease management in citrus orchards.ref.7.16 ref.12.43 ref.16.3

Varieties:

Varieties of Clementines and Tangerines

The document excerpts provide information on the main varieties of clementines and tangerines discussed. These include the Clemenules, Nova, Ortanique, and Tango cultivars.ref.28.114 ref.16.3 ref.7.16

1. Clemenules is considered the most representative cultivar of clementines and is classified as an early mandarin. It has a relatively early harvesting period, extending from early September to late December.ref.7.16 ref.7.152 ref.16.3 This variety is known for its unique characteristics and is highly sought after in the market.ref.7.152 ref.7.16 ref.16.3

2. Nova is a hybrid variety that was introduced into Spanish citriculture to meet the late-season mandarin demand of international markets. It extends the harvesting period until May, offering consumers a longer availability of this citrus fruit.ref.25.23 ref.58.182 ref.7.152

3. Ortanique is another hybrid variety that was also introduced to meet the late-season mandarin demand. Similar to the Nova variety, it extends the harvesting period until May, providing a longer window for consumers to enjoy these fruits.ref.25.23 ref.7.152 ref.7.16

4. Tango is an interesting alternative to be commercialized when the clementine season comes to an end. It is a mid- to late-maturing variety and can be harvested from the end of December to the end of February.ref.7.16 ref.7.122 ref.7.122 Tango serves as a continuation of the clementine season, offering consumers a similar flavor profile during the later months.ref.7.16 ref.7.122 ref.7.152

These varieties each have their unique characteristics and contribute to the overall diversity of clementines and tangerines available in the market. The introduction of hybrid varieties such as Nova and Ortanique has allowed for an extended harvesting period, meeting the demands of consumers who enjoy these fruits later in the season.ref.7.16 ref.7.122 ref.25.23

The provided document excerpts do not contain specific information about the Ortanique and Nova varieties and their characteristics and taste profiles. Therefore, it is not possible to determine how these varieties differ in terms of their characteristics and taste profiles based on the given information.

The best practices for harvesting clementines and tangerines depend on the specific cultivar and the desired quality of the fruit. For example, clementines like the 'Clemenules' variety are considered early mandarins and are typically harvested from early September to late December. At the beginning of the season, these clementines are often subjected to degreening ethylene treatment to enhance their external color.ref.7.152 ref.7.16 ref.7.97

On the other hand, tangerines such as the 'Tango' cultivar are mid-late season maturing varieties and are harvested from the end of December to the end of February. However, the optimal time to harvest 'Tango' mandarins and the changes in fruit quality during this period are still being studied. It is crucial to conduct further research and study the specific characteristics of each cultivar to determine the optimal harvest time and ensure high-quality fruit.ref.7.122 ref.7.152 ref.7.152

It is worth noting that the choice of rootstock onto which the mandarin cultivar is grafted can also influence the harvest time and fruit quality. The rootstock plays a crucial role in determining the maintenance of acidity and sugar contents throughout the harvest and affects external coloration. In Spain, the most widely used rootstock is Carrizo Citrange (CC), which is known for its tolerance to citrus tristeza virus.ref.7.122 ref.7.231 ref.7.244 However, it may also present problems such as iron chlorosis and salinity.ref.7.231 ref.7.228 ref.7.231

Flavor Profiles

The flavor profiles of different clementine and tangerine varieties can vary based on several factors. These include genotypic differences, preharvest climatic conditions, cultural practices, maturity, and harvesting methods. Additionally, the content of organic acids and sugars can differ depending on species, varieties, processing, and environmental and horticultural conditions.ref.25.23 ref.25.23 ref.11.30 The document mentions that a comprehensive analysis of fruit quality traits in 46 distinct mandarin varieties revealed wide genetic variability among mandarin varieties, indicating high genetic diversity in fruit quality traits among citrus species and varieties.ref.25.23 ref.11.30 ref.25.23

The provided document excerpts do not contain specific information about the impact of genotypic differences on the flavor profiles of clementines and tangerines, or the specific genetic traits that contribute to certain flavor characteristics. Therefore, there is no information available to answer the question.ref.51.2 ref.51.2 ref.51.2

Preharvest climatic conditions and cultural practices can affect the flavor of clementines and tangerines. The flavor of citrus fruits is influenced by the balance between soluble solids and acidity in the juice, which is determined by factors such as air temperature, relative air humidity, and thermal variation throughout the day. In tropical regions with high and constant average temperatures, low fruit quality is observed due to the high respiratory activity of fruits, resulting in lower concentration of soluble solids and acidity.ref.7.231 ref.33.109 ref.42.8 On the other hand, in regions with a Mediterranean climate, fruits have higher quality and greater commercial acceptance due to hot and dry summers, mild humid winters, and high thermal amplitude. The color of the fruit peel is regulated by air temperature and daily thermal amplitude, with chlorophyll degradation and carotenoid accumulation favored at temperatures below 13 ºC and delayed at temperatures above 20 ºC. Additionally, mandarins produced under temperatures above 30 ºC have low quality.ref.42.8 ref.42.8 ref.25.447 Cultural practices, such as crosses between species, can also affect fruit quality. For example, crossing mandarin trees with grapefruit trees can result in hybrids called tangelos, which are more adapted to tropical climates. These factors interact with each other to determine the overall flavor of clementines and tangerines.ref.33.84 ref.25.447 ref.42.8

The flavor of clementines and tangerines can be influenced by maturity and harvesting methods. In the case of early mandarins in the Mediterranean Region, fruit can be harvested before full external coloration and then subjected to ethylene degreening treatment to enhance external color. Alternatively, fruit can be harvested later when it has completed typical external coloration.ref.7.97 ref.7.97 ref.7.228 The rootstock used can also affect the internal quality parameters, such as acidity and sugar contents, which can determine the harvest time and influence the maintenance of these parameters throughout harvest. Different rootstocks can also affect the external color of the fruit, allowing for advanced harvests. For example, the 'Clemenules' clementine is an early mandarin that reaches internal maturity before full coloration, so it is usually submitted to degreening ethylene treatment to enhance external color.ref.7.97 ref.7.228 ref.7.113 The rootstock can also affect the maintenance of acidity levels throughout the harvest, which is important for prolonging the commercial period and maintaining fruit quality. However, the optimal stages of maturity and specific harvesting techniques that result in the best flavor may vary depending on the specific variety, rootstock, and growing conditions.ref.7.97 ref.7.106 ref.7.34

The volatile profiles of different clementine varieties can also vary, with differences in the levels of monoterpenic compounds, aliphatic aldehydes, acetic esters, and sesquiterpenes. These compounds contribute to the aroma and flavor of the fruits and can result in distinct taste experiences.ref.25.248 ref.48.26 ref.48.26

However, the specific flavor profiles of different clementine and tangerine varieties were not explicitly mentioned in the provided document excerpts. Further research and analysis would be necessary to obtain comprehensive information on the flavor profiles of these varieties.ref.48.3 ref.51.3 ref.51.3

In conclusion, the document excerpts provide insights into the main varieties of clementines and tangerines, including Clemenules, Nova, Ortanique, and Tango. These varieties contribute to the overall diversity of citrus fruits available in the market. Factors such as genotypic differences, environmental conditions, and horticultural practices can influence the appearance and color of these fruits.ref.7.229 ref.7.16 ref.7.122 Additionally, the flavor profiles of clementines and tangerines can vary based on various factors such as genotypic differences, preharvest climatic conditions, cultural practices, maturity, and harvesting methods. While the document does not provide specific details on appearance, color, and flavor differences among varieties, it highlights the importance of genetic diversity in fruit-quality traits among citrus species and varieties. Further research and analysis are necessary to obtain a comprehensive understanding of the characteristics and flavor profiles of different clementine and tangerine varieties.ref.7.229 ref.11.30 ref.7.16

Market Demand:

Global Demand for Clementines and Tangerines

The global demand for clementines and tangerines is significant. Oranges account for half of the global citrus production and represent over 40% of world citrus exports. Following oranges, tangerines/mandarins, lemons/limes, and grapefruit are the most prominent citrus fruits in terms of global production and export.ref.15.17 ref.28.301 ref.39.25 Among these, tangerines/mandarins make up a substantial portion of global citrus exports, estimated at nearly 30%. China, South Africa, and Turkey are the major exporters of tangerines/mandarins, while Mexico, South Africa, and Turkey have higher lemon exports.ref.28.301 ref.15.17 ref.15.17

Spain, being the fifth largest producer of citrus fruits globally and the first one in the Mediterranean region, plays a significant role in the production of clementines. In 2009, the production of Spanish citrus, including mandarins, clementines, and satsumas, was estimated at over 100 million tons. Spain is known for its significant production of clementines and is a major player in the global market.ref.25.377 ref.15.17 ref.15.17 However, the specific global demand for clementines and tangerines is not explicitly mentioned in the provided document excerpts.ref.7.16 ref.15.17 ref.15.17

The demand for citrus and clementines in North America and Europe is significant. Citrus production and consumption have experienced strong growth since the mid-1980s, with larger production levels enabling higher levels of total and per capita consumption of citrus. Clementines, in particular, are highly preferred by European consumers, with France importing about 278,000 Mt of clementines in 2006.ref.15.17 ref.39.25 ref.15.17 Spain and Morocco are the two biggest exporters of clementines, with Spain exporting 249,965 Mt and Morocco exporting 22,938 Mt. The consumption of clementines by Europeans is very high, and clementines are usually grown in Morocco and Spain. However, it is difficult to determine the exact geographical origin of various clementines due to mixing of batches from different sources.ref.15.17 ref.15.17 ref.15.17 Traceability is assured through rigorous labeling and administrative documentation. The document also mentions the importance of citrus fruits, such as oranges, lemons, limes, and grapefruits, in the global citrus industry, with oranges accounting for over 40% of citrus production and exports. The production of citrus fruits, including oranges, tangerines, lemons, and limes, has grown continuously over the past three decades.ref.39.25 ref.39.25 ref.15.17 Additionally, the document highlights the commercial importance of sweet oranges, lemons, limes, grapefruits, and tangerines, which are grown in over 140 countries worldwide. The United States, Brazil, Mexico, Argentina, China, Spain, South Africa, Italy, Costa Rica, and Turkey are the top ten countries that process citrus fruits. Overall, the demand for citrus and clementines in North America and Europe is driven by their popularity and consumption patterns in these regions.ref.39.25 ref.39.25 ref.15.17

Emerging Market Trends for Clementines and Tangerines

The emerging market trends for clementines and tangerines revolve around the introduction of new mid- and late-season mandarin varieties with seedless fruit. These varieties cater to the market demand from February to May, filling the gap when the supply of other citrus fruits dwindles. One such variety gaining popularity among Spanish citrus producers is the 'Tango' mandarin.ref.7.152 ref.7.122 ref.7.152 The production of 'Tango' mandarins is mainly concentrated in Andalusia, Spain.ref.7.122 ref.7.152 ref.25.377

In response to the growing demand for high-quality mandarins throughout the season, the harvesting period has been extended, and late-season mandarin varieties have been introduced. Consumers have shown a preference for seedless fruit in the fresh fruit market, leading to an increased focus on seedless mandarin production. The 'Tango' mandarin cultivar is being introduced as an alternative to be commercialized when the clementine season ends.ref.7.16 ref.7.152 ref.7.16 This variety is characterized by its low seed count and high organoleptic quality, making it highly sought after worldwide.ref.7.152 ref.7.122 ref.7.16

The consumption and demand for clementines and tangerines have been steadily increasing. However, the provided document excerpts do not provide specific information on the market demand for clementines and tangerines beyond these general trends. Nonetheless, it is evident that the introduction of new varieties and the extension of the harvesting period are responses to this growing demand for small-sized, easy-peel, and seedless citrus fruits.ref.7.152 ref.7.16 ref.7.16

The emerging market trends for clementines and tangerines have impacted overall citrus fruit consumption and demand. The Valencian Community in Spain is the leading producer of clementines, with 'Clemenules' being the most representative cultivar. The production of clementines in Spain accounts for 74% of the total production.ref.7.16 ref.15.17 ref.15.17 Additionally, the introduction of new varieties and extended harvesting periods, such as the 'Tango' mandarin, has contributed to the growing demand for clementines and tangerines. The 'Tango' mandarin is a mid-late season maturing variety that is becoming popular among Spanish citrus producers. The demand for clementines and tangerines is particularly high in Europe, with France importing a significant amount of clementines in 2006.ref.7.152 ref.7.16 ref.7.16 Spain is the first exporting country of fresh mandarins and is the fifth worldwide producer of citrus fruits. The Mediterranean region, including Spain, is the leading citrus fruit-producing region, accounting for 19% of the world citrus production. However, the demand for clementines and tangerines is not limited to Europe, as these fruits are also popular in South Asia, the Middle East, and other regions.ref.15.17 ref.15.17 ref.25.377

Price Fluctuations of Clementines and Tangerines

According to the provided document excerpts, the price of clementines and tangerines fluctuates based on supply and demand dynamics. The demand for small citrus fruits, such as clementines and mandarins, has been rising due to consumer preferences for small-sized, easy-peel, and seedless fruits. However, the lack of seedless mandarin production after February and the increasing consumption and demand for these fruits have prompted the introduction of new varieties to supply the market, primarily from February to May.ref.7.152 ref.16.3 ref.7.16

Preharvest climatic conditions and cultural practices can have an impact on the flavor profiles of clementines and tangerines. The characteristics of mandarins, including their flavor, can be influenced by climate factors such as air temperature and relative humidity. In tropical regions with high and constant average temperatures, lower fruit quality is usually observed due to the high respiratory activity of fruits, resulting in lower concentration of soluble solids and acidity.ref.7.167 ref.7.165 ref.7.231 On the other hand, in regions with a Mediterranean climate, with hot and dry summers and mild humid winters, fruits have higher quality and greater commercial acceptance. The balanced relationship between soluble solids and acidity is decisive for the characteristic flavor of citrus. Cultural practices, such as the use of specific rootstocks, can also impact fruit quality.ref.7.34 ref.7.165 ref.7.231 For example, crosses between mandarin trees and grapefruit trees have been used to produce hybrids called tangelos, which are more adapted to tropical climates. Rootstock selection can influence the acidity content, total soluble solids, sugars, vitamin C, and citric acid in fruit. The rootstock can also affect the susceptibility of fruit to chilling injury and postharvest disorders.ref.7.97 ref.7.228 ref.7.34 Overall, preharvest climatic conditions and cultural practices play a significant role in shaping the flavor profiles of clementines and tangerines.ref.7.97 ref.7.165 ref.7.97

The genetic diversity of fruit quality traits among citrus species and varieties is well-documented. Various factors, such as genotypic differences, preharvest climatic conditions, cultural practices, maturity, and harvesting methods, can influence the vitamin C content, organic acids, sugars, and other nutritional and biochemical attributes of citrus fruits. Studies have shown that there is wide genetic variability among mandarin varieties and natural subgroups, indicating high genetic diversity in fruit-quality traits among citrus species and varieties.ref.11.30 ref.11.78 ref.11.30 The genetic diversity in citrus is a major challenge in classifying the increasing number of citrus varieties. Swingle and Tanaka proposed classification methods based on native and cultivated varieties, respectively, and identified the contributions of different citrus species to the genome constitution of secondary species and hybrids. The use of molecular markers and sequencing techniques has facilitated the determination of the genealogy and phylogenetic history of citrus, highlighting the genetic basis of diversity in citrus fruits.ref.11.78 ref.11.78 ref.11.30 The genetic diversity among citrus accessions has been investigated using nuclear and mitochondrial markers, and genetic diversity statistics have been calculated for each marker within and between different citrus groups. Citrus species have a complex reproductive biology, and conventional breeding methods face limitations such as long juvenile periods, heterozygosity, and lack of resistance against important pathogens. Genetic transformation offers alternatives for genetic improvement, allowing the introduction of specific traits into known genotypes without altering their genetic background.ref.11.30 ref.11.78 ref.11.31 The potential applications of genetic engineering in citrus breeding include the development of disease- and insect/pest-resistant varieties. The production and management of citrus are influenced by soil and climate conditions, and the demand for citrus fruits and their derivatives remains high due to their sensory, nutritional, and health-related qualities. The identification of QTLs associated with citrus Huanglongbing (HLB) infection can facilitate the development of resistant cultivars through marker-assisted selection or genome editing.ref.11.31 ref.11.32 ref.11.31 High-density genetic mapping and fine accuracy are crucial for identifying QTLs associated with phenotypic traits, and advancements in high-throughput genome sequencing and SNP genotyping have improved the construction of genetic maps for citrus.ref.11.31 ref.11.78 ref.11.32

The document excerpts do not provide specific information about new varieties that have been introduced to supply the market from February to May, or how they have impacted the price and demand for clementines and tangerines.

The 'Tango' mandarin cultivar has gained attention as an alternative to be commercialized when the clementine season ends. With its low seed count and high organoleptic quality, the 'Tango' mandarin is in high demand worldwide. The introduction of new, high-quality, mid and late-season mandarin varieties with seedless fruits has been a focus in Mediterranean citriculture.ref.7.16 ref.7.152 ref.7.122 It is expected that the 'Tango' mandarin will experience exponential growth in production in Spain. Nonetheless, the provided document excerpts do not provide specific information on the price fluctuations of clementines and tangerines based on supply and demand.ref.7.152 ref.7.122 ref.7.121

Consumption Patterns of Clementines and Tangerines

The consumption patterns of clementines and tangerines vary across different countries. Clementines have a large demand and commercial consumption worldwide due to their ease of peeling and seedlessness. They are popular in many countries, including those in Europe, the Middle East, and the United States.ref.16.3 ref.39.25 ref.7.16 The preference for clementines stems from their convenient characteristics, making them a favored choice for consumers seeking a quick and hassle-free snack.ref.16.3 ref.7.16 ref.7.16

On the other hand, tangerines have a significant market in Spain, where it is the leading tangerine producer in the Mediterranean region. Spain also exports a substantial portion of its tangerine production, with Germany, France, and the United Kingdom being important markets. China, as the world's leading producer of tangerines, holds a significant market share as well.ref.28.301 ref.15.17 ref.15.17

In summary, the global demand for clementines and tangerines is substantial, with tangerines/mandarins representing a significant portion of global citrus exports. Spain plays a crucial role in the production of clementines, while China leads in tangerine production. Emerging market trends include the introduction of new mid- and late-season mandarin varieties with seedless fruit to meet the growing demand.ref.15.17 ref.28.301 ref.7.16 The 'Tango' mandarin cultivar has gained popularity in Spain due to its low seed count and high organoleptic quality. Price fluctuations of clementines and tangerines are influenced by supply and demand dynamics, but specific information on these fluctuations is not provided. Consumption patterns vary across different countries, with clementines enjoying widespread popularity for their ease of peeling and seedlessness, while tangerines have a significant market in Spain and China.ref.7.122 ref.7.152 ref.28.301

Trade and Distribution:

Storage Techniques for Prolonging Shelf Life

Cold storage is the primary method used to preserve the postharvest life and extend the marketing time of citrus fruits such as clementines and tangerines. By subjecting the fruits to specific temperatures, cold storage effectively slows down respiration and other metabolic processes, thereby prolonging their shelf life. However, it's crucial to note that the storage temperature plays a critical role in maintaining the quality of these fruits.ref.25.447 ref.25.447 ref.25.43 Improper temperature control can lead to physiological disorders and reduce consumer acceptance.ref.25.447 ref.25.43 ref.41.16

Among the various citrus varieties, mandarins, which include clementines and tangerines, are particularly susceptible to chilling injury when exposed to prolonged cold storage at low temperatures. Each cultivar has a specific critical temperature at which chilling injury occurs. Therefore, it is necessary to establish suitable storage temperatures and durations based on the response of the particular cultivar to those temperatures.ref.25.447 ref.25.447 ref.25.358 This ensures that the fruits are stored under optimal conditions that minimize the risk of chilling injury.ref.25.447 ref.25.361 ref.25.37

It's important to highlight that the optimum storage conditions for safe and long-term storage of clementines and tangerines may vary depending on the specific cultivar. This emphasizes the need for careful consideration of the storage requirements of each variety to ensure their optimal preservation. By understanding the critical storage temperature for each cultivar, growers and distributors can implement appropriate storage techniques that maintain the quality of the fruits and extend their shelf life.ref.25.447 ref.7.232 ref.25.447

Challenges in Trade and Distribution

The trade and distribution of clementines and tangerines are not without challenges. Freeze-damage is one such challenge, especially in regions with colder climates. Frost and freezing temperatures can cause significant damage to the fruits, leading to loss of quality and market value.ref.25.447 ref.25.447 ref.25.37 Therefore, it is crucial to implement strategies to protect the fruits from freeze-damage during transportation and storage, such as using appropriate packaging and insulation.ref.25.447 ref.25.447 ref.25.37

Inadequate management of refrigerated storage and transport also poses challenges in the trade and distribution of these citrus fruits. Maintaining the proper temperature and humidity levels throughout the supply chain is essential to ensure the preservation of postharvest quality. Failure to do so can result in a reduction in the shelf life and overall quality of the fruits, ultimately impacting consumer acceptance and marketability.ref.25.447 ref.25.447 ref.25.43

Clementines and tangerines are particularly susceptible to low temperatures, including chilling injury as mentioned earlier. Therefore, it is vital to handle these fruits with care and avoid exposing them to extended periods of cold storage. By implementing suitable storage durations and temperatures, growers and distributors can minimize the risk of chilling injury and maintain the quality of the fruits.ref.25.447 ref.25.358 ref.25.447

The demand for seedless fruit presents another challenge in meeting market demands. While clementines and tangerines are generally seedless, the introduction of new varieties and the need for consistent seedlessness require careful cultivation and selection practices. Growers must ensure that the fruits meet consumer preferences for seedless varieties, as these are often favored in the market.ref.7.16 ref.11.33 ref.16.3

To minimize the risk of chilling injury in clementines and tangerines during storage, growers and distributors can implement several techniques and practices. One approach is to carefully manage the temperature during storage. It is important to store the fruits at temperatures that are suitable for the specific variety, as different varieties have different critical temperatures for chilling injury.ref.25.447 ref.25.447 ref.25.358 Additionally, the duration of storage at low temperatures should be considered, as injury symptoms generally increase with longer exposure. Another technique is to select appropriate rootstocks for the citrus trees, as rootstocks can affect the susceptibility of the fruit to chilling injury and other physiological disorders. Proper fruit handling and packing operations can also help reduce mechanical damages that can lead to increased respiration rate and physiological disorders.ref.25.447 ref.25.358 ref.25.37 Modified atmosphere packaging (MAP) using specific packaging materials can be employed to create an optimal atmosphere around the fruit, reducing the development of postharvest disorders.ref.25.447 ref.25.43 ref.25.447

As for challenges faced by growers in ensuring seedlessness in clementines and tangerines, especially with the introduction of new varieties, specific examples were not provided in the provided document excerpts.ref.11.79 ref.11.33 ref.11.79

Consumer preferences for seedless varieties can impact the cultivation and selection practices of growers. Growers may need to focus on cultivating and selecting seedless varieties to meet the demand of consumers. This may involve breeding programs to develop new seedless varieties or grafting seedless scions onto appropriate rootstocks.ref.27.116 ref.27.116 ref.11.29 Meeting these preferences can present additional challenges, such as ensuring the fruit quality and reducing the risk of physiological disorders associated with seedlessness.ref.27.116 ref.11.33 ref.11.29

In addition to these challenges, factors such as location, rootstock, and preharvest conditions can influence the postharvest behavior and quality of clementines and tangerines. These factors must be considered during cultivation and harvesting to ensure that the fruits are in optimal condition for postharvest handling and commercialization. By implementing proper cultivation, harvesting, post-harvest, and commercialization practices, growers and distributors can overcome these challenges and ensure the successful trade and distribution of clementines and tangerines.ref.7.152 ref.33.109 ref.7.97

Conclusion

In conclusion, the storage techniques used to prolong the shelf life of clementines and tangerines rely on cold storage at specific temperatures. However, it is crucial to establish suitable storage conditions for each cultivar to prevent chilling injury and maintain the quality of the fruits. Challenges in the trade and distribution of these fruits include freeze-damage, inadequate management of refrigerated storage and transport, susceptibility to low temperatures, and the need to meet market demands for seedless varieties.ref.25.447 ref.25.358 ref.25.447 Overcoming these challenges requires proper cultivation, harvesting, post-harvest, and commercialization practices. By addressing these challenges and implementing appropriate strategies, growers and distributors can ensure the successful trade and distribution of clementines and tangerines while maintaining their postharvest quality.ref.25.447 ref.25.358 ref.25.447

Economic Impact:

The Contribution of Clementine and Tangerine Cultivation to the Agricultural Sector

Clementine and tangerine cultivation make a significant contribution to the agricultural sector, particularly in Spain. As the fifth largest producer of citrus fruits worldwide and the leading producer in the Mediterranean region, Spain has a substantial area dedicated to clementines and tangerines. In 2009, the cultivation of clementines and tangerines accounted for 38% of the total citrus fruit area in Spain.ref.15.17 ref.15.17 ref.15.17

Among mandarins, the clementine group holds the highest importance, representing 74% of the total production in the Valencian Community. Spain is also the first producer of tangerines in the Mediterranean region, with a production of 1,967 thousand tons. The production of tangerines has been on the rise, accounting for 45% of the total citrus production in the Comunitat Valenciana.ref.15.17 ref.15.17 ref.7.16 Over the years, the cultivation of tangerines has experienced a significant increase of 32.11%. The surface area dedicated to tangerines has expanded from 67,585 hectares in 1992/93 to 91,611 hectares in 2008/09.ref.15.17 ref.15.17 ref.15.17

The expansion of clementine and tangerine cultivation has played a vital role in the overall citrus fruit production in Spain. By focusing on these crops, Spain has been able to increase its citrus production and maintain its position as a leading global producer. The success of clementine and tangerine cultivation can be attributed to factors such as favorable climatic conditions, suitable soil quality, and skilled agricultural practices.ref.15.17 ref.15.17 ref.15.17 The agricultural sector in Spain has recognized the potential of these crops and has made substantial investments to further develop and expand their cultivation.ref.15.17 ref.15.17 ref.7.16

Impact of the Clementine and Tangerine Industry on the Economy

The clementine and tangerine industry not only contributes to the agricultural sector but also has a significant impact on the overall economy of producing regions, especially in Spain. As the second-largest producer of tangerines in the world, Spain dedicates a considerable portion of its annual production to international marketing. Approximately 70% of Spain's tangerine production is exported, highlighting the importance of this sector in the country's economy.ref.15.17 ref.15.17 ref.15.17

The cultivation, harvesting, post-harvest, and commercialization of clementines and tangerines play a crucial role in the overall economy of Spain. These activities generate employment opportunities, both directly and indirectly, in rural areas where citrus cultivation is prevalent. The industry provides jobs for agricultural workers, as well as workers in packing houses, transportation, and distribution.ref.7.16 ref.7.16 ref.7.16 The availability of employment opportunities contributes to the socioeconomic development of the producing regions, particularly in rural communities.ref.25.22 ref.25.20 ref.7.14

However, the clementine and tangerine industry also faces challenges that can impact the overall economy. Freeze damage is a significant concern for citrus fruits, including clementines and tangerines. Freezing temperatures can affect the quality and marketability of the fruits, leading to financial losses for growers and exporters.ref.25.447 ref.25.37 ref.25.447 To mitigate this risk, proper management of refrigerated storage and transport is essential. Maintaining the optimal temperature during storage and transportation helps prevent freezing and preserve the quality of the fruits.ref.25.447 ref.25.447 ref.25.37

Despite these challenges, the economic impact of the clementine and tangerine industry is substantial. The sector contributes to export revenue, as well as overall economic growth in the producing regions. The revenue generated from the export of clementines and tangerines adds to the country's foreign exchange reserves and strengthens its economy.ref.39.25 ref.7.16 ref.7.16 Additionally, the industry's growth and success contribute to the country's reputation as a reliable supplier of high-quality citrus fruits, attracting international buyers and further stimulating economic activity.ref.39.25 ref.39.25 ref.39.25

Potential Economic Benefits of Expanding Clementine and Tangerine Cultivation

Expanding clementine and tangerine cultivation offers numerous potential economic benefits, including increased production, exportation, economic growth, and job creation. Citrus fruits, including mandarins, clementines, and satsumas, are highly popular and economically important fruit crops grown in tropical and subtropical climates worldwide. Spain, as the fifth largest producer of citrus fruits globally and the leading producer in the Mediterranean region, has experienced significant growth in citrus production.ref.15.17 ref.39.25 ref.7.16

Clementines, particularly tangerines, are the most important group among mandarins, with high production in the Valencian Community in Spain. Spain also holds the distinction of being the second-largest producer and the first exporting country of fresh mandarins. Expanding the cultivation of clementines and tangerines would help meet the increasing demand for these fruits, particularly during the period from February to May when there is a lack of mandarin production.ref.7.16 ref.28.301 ref.15.17 This expanded cultivation can lead to increased production and exportation of clementines and tangerines, resulting in economic growth and job creation in the citrus industry.ref.7.16 ref.15.17 ref.15.17

Furthermore, the development of new late-maturing triploid mandarin varieties through breeding programs can bring additional economic benefits. These new varieties are known for their excellent fruit quality traits, including large fruit size, seedlessness, attractive rind color, and easy peeling. Such high-quality varieties command premium prices in the market, leading to increased profitability for citrus growers.ref.25.23 ref.25.23 ref.7.152 Expanding the cultivation of clementines and tangerines, along with the adoption of new and improved varieties, can enhance the competitiveness of the Spanish citrus industry in the global market.ref.7.122 ref.12.43 ref.7.16

Additionally, the utilization of citrus by-products, such as peels and seeds, can contribute to the development of value-added products. Citrus peels can be processed to extract essential oils, which are widely used in the fragrance and flavor industries. Citrus seeds can be utilized for the extraction of oils, which have various applications in the food and cosmetic industries.ref.23.33 ref.23.32 ref.23.32 The development of value-added products from citrus by-products not only adds to the revenue streams of citrus growers but also reduces waste management costs for the citrus industry.ref.23.33 ref.23.32 ref.23.32

In conclusion, clementine and tangerine cultivation play a significant role in the agricultural sector and the overall economy, particularly in Spain. The expansion of these crops has contributed to the increased production of citrus fruits and has helped Spain maintain its position as a leading global producer. The clementine and tangerine industry has provided employment opportunities, generated export revenue, and stimulated economic growth in the producing regions.ref.7.16 ref.7.16 ref.7.16 Expanding the cultivation of clementines and tangerines offers potential economic benefits such as increased production, exportation, and the development of value-added products. With the adoption of new varieties and the utilization of citrus by-products, the Spanish citrus industry can further enhance its competitiveness and achieve sustainable economic growth.ref.7.16 ref.7.16 ref.7.16

The unique characteristics of Clemenules contribute to its high demand in the market due to its volatile profile and fruit quality. Compared to other clementine varieties, Clemenules has higher levels of monoterpenic compounds, aliphatic aldehydes, and acetic esters, as well as sesquiterpenes. It also has lower levels of certain lipid-derived compounds.ref.25.248 ref.7.16 ref.16.3 These differences in volatile compounds contribute to the distinct aroma and flavor of Clemenules, making it desirable to consumers. Additionally, Clemenules is known for its outstanding fruit quality, including its size, weight, diameter/height ratio, rind size, color, percentage of juice, and absence of seeds. These characteristics make it easy to peel and enjoyable to eat.ref.16.3 ref.25.248 ref.7.16 The high demand for Clemenules is also attributed to its popularity among European consumers, who appreciate its taste, ease of peeling, and seedlessness. It is one of the most important cultivated citrus mandarins and is widely consumed in Europe. The cultivation of Clemenules is also favored by its early harvest period, which allows it to be available in the market from early September to late December.ref.16.3 ref.7.16 ref.7.16 Overall, the combination of its unique volatile profile, fruit quality, and consumer preference contributes to the high demand for Clemenules in the market.ref.25.248 ref.16.3 ref.7.16

The specific qualities that make the Nova hybrid variety well-suited for meeting the late-season mandarin demand of international markets include late harvest, good fruit quality (including size, seedlessness, good rind color, and easy peeling), and high nutritional quality (including high levels of vitamin C and total phenolics). The Nova hybrid variety is part of a breeding program carried out in the Plant Protection and Biotechnology Center in the Instituto Valenciano de Investigaciones Agrarias (IVIA) in Spain, aimed at obtaining new triploid mandarin varieties with late harvest. These new hybrids have been selected for commercial production due to their agronomic performance and excellent fruit quality traits.ref.25.23 ref.25.445 ref.25.23 They are mid- and late-maturing, with good rind color and easy peeling. In terms of nutritional quality, the new hybrids, including Nova, exhibit high levels of vitamin C and total phenolics, comparable to or even higher than their parent varieties. These qualities make the Nova hybrid variety suitable for meeting the late-season mandarin demand of international markets.ref.25.23 ref.25.311 ref.25.311

Appearance and Color Variation

The document excerpts briefly mention that the appearance and color of clementines and tangerines can vary among different varieties. However, specific details regarding the appearance and color differences are not provided. It is important to note that factors such as genotypic differences, environmental conditions, and horticultural practices can influence the appearance and color of these fruits.ref.7.34 ref.7.97 ref.7.34

Genotypic differences refer to the genetic makeup of each variety, which can result in variations in physical characteristics. Environmental conditions, such as temperature and sunlight exposure, can also impact the coloration of the fruit. Horticultural practices, including fertilization and irrigation techniques, may further influence the appearance and color of clementines and tangerines.ref.11.134 ref.11.31 ref.11.135

Additionally, the document mentions that clementines are often subjected to degreening ethylene treatment to enhance their external color. This treatment involves exposing the fruits to ethylene gas, which stimulates color development. By implementing degreening ethylene treatment, producers can ensure a more appealing appearance of clementines in the market.ref.25.167 ref.25.107 ref.25.184

While the document does not provide specific information on appearance and color differences among varieties, it is evident that these factors play a significant role in determining the visual characteristics of clementines and tangerines.ref.7.34 ref.7.34 ref.7.34

Genotypic differences contribute to the appearance and color variation in clementines and tangerines. According to the provided document excerpts, there is high genetic diversity among citrus species and varieties, resulting in vast variation in fruit-quality traits. This genetic diversity is influenced by factors such as frequent bud mutation, interspecific and intergeneric hybridization, and other breeding techniques.ref.28.303 ref.11.31 ref.11.31

Environmental conditions can also have a noticeable impact on the coloration of these fruits. For example, in the Mediterranean region, early mandarins are harvested before full coloration and are then subjected to ethylene degreening treatment to enhance external color. Additionally, the use of rootstocks can influence the external color of citrus fruits, potentially leading to advanced harvests.ref.7.97 ref.25.23 ref.7.228

Horticultural practices, such as fertilization and irrigation techniques, can specifically influence the appearance and color of clementines and tangerines. The content of organic acids and sugars in these fruits may vary according to environmental and horticultural conditions, such as climate, rootstock, and irrigation. Furthermore, the enhancement of certain secondary metabolites, such as carotenoids, through genetic engineering can contribute to the development of better-colored citrus fruits.ref.11.34 ref.7.34 ref.7.34

The optimal harvest time for clementines and tangerines is determined by several factors, including the cultivar and desired fruit quality. In the case of early mandarins in the Mediterranean Region, fruit can be harvested at the beginning of the season, even before full external coloration, and then submitted to ethylene degreening treatment to enhance external color. The degreening treatment with ethylene accelerates chlorophyll degradation and carotenoid biosynthesis, resulting in improved external color.ref.7.97 ref.7.97 ref.7.16 However, the time required to reach the desired color of the fruit depends on the initial fruit color, and longer exposure time to ethylene can make the fruit more susceptible to senescence alterations.ref.25.108 ref.25.108 ref.25.23

Regarding the potential drawbacks or risks associated with degreening ethylene treatment, the longer the exposure time, the more susceptible citrus fruit is to senescence alterations. Additionally, the incidence of disorders such as calyx senescence can be accentuated by post-treatment storage time, especially when fruit is exported to more distant countries with strict cold-quarantine treatments. However, the degreened fruit intended for the European Union market has less risk of manifesting disorders compared to fruit exported to countries like the USA or Japan.ref.25.438 ref.25.437 ref.25.227

Using the Carrizo Citrange rootstock may lead to potential problems of iron chlorosis and salinity. Iron chlorosis is a condition where the leaves of the citrus tree turn yellow due to iron deficiency, and salinity refers to the presence of excessive salts in the soil, which can negatively affect plant growth. However, there are alternative rootstocks available that can mitigate these issues while still providing tolerance to citrus tristeza virus.ref.42.10 ref.12.39 ref.7.232

The document excerpts provide information on the demand for clementines and citrus fruit in North America and Europe.ref.39.25 ref.39.25 ref.39.25

In Europe, clementines are highly preferred by consumers and have a high consumption rate. For example, in 2006, France imported about 278,000 metric tons of clementines, with Spain and Morocco being the biggest exporters of clementines to Europe. The consumption of clementines in Europe has shown an increasing trend over the years.ref.15.17 ref.7.16 ref.58.178 Additionally, regulations in Europe are tightened to ensure quality and safety, and traceability and labeling of imported citrus products are compulsory.ref.39.25 ref.15.17 ref.39.25

In North America, the production and consumption of citrus fruits, including clementines, have also witnessed significant growth. Oranges, tangerines, lemons, and limes have expanded rapidly in production, leading to higher levels of consumption. Processed citrus products have also experienced faster growth.ref.39.25 ref.39.25 ref.39.26 However, specific information on the demand for clementines in North America is not provided in the document excerpts.ref.39.25 ref.39.26 ref.39.25

The document excerpts do not provide specific information about the demand for clementines and citrus fruits in North America and Europe by weight.

Works Cited