Fruit-tree related terminology and categorization – Pomology

What is pomology?

Pomology, derived from the Latin word “pomum,” meaning fruit, is the scientific field devoted to the study and cultivation of fruit trees and their fruits. As an interdisciplinary branch of horticulture, pomology encompasses a wide range of disciplines, including botany, genetics, physiology, and agronomy. Through the diligent exploration of fruit tree species, their growth patterns, genetic variations, and fruit production, pomologists develop and enhance the quality, yield, and diversity of fruits, making significant contributions to the agricultural industry.

Which are the main four fruiting categories of pomology?

Pomology divides fruiting trees into various categories based on several factors, including botanical classification, fruit type, growth habit, and climatic requirements. The primary categorization is often based on fruit type and includes pome fruits, stone fruits, nuts, and citrus.

Which trees fall into the Pome Fruits category?

• Pome Fruits:

Pome fruits belong to the Rosaceae family and are characterized by a core surrounded by a fleshy edible layer. Examples of pome fruits include apples, pears, and quinces. These fruits have a distinctive texture and are typically rich in nutrients, making them popular choices for fresh consumption, cooking, and processing into various products such as juices and sauces.

Which trees fall into the Stone fruits category?

• Stone Fruits:

Stone fruits, also known as drupes, are classified under the Rosaceae family as well. They are characterized by a single seed (stone or pit) surrounded by a fleshy exterior. Common stone fruits include peaches, plums, cherries, apricots, nectarines, and crimson. Stone fruits are prized for their succulent flavors and are enjoyed fresh, dried, canned, and used in various culinary creations.

Which trees fall into the Nuts category?

• Nuts:

Nuts are defined by the presence of seeds encased within a hard, woody shell. They are typically formed from the ovary wall of the tree’s flower, which undergoes a process of maturation and hardening to protect the seed within. Some well-known nut trees include almonds, chestnuts, walnuts, pistachios, and hazelnuts.

Which trees fall into the Citrus category?

• Citrus Fruits:

Citrus fruits belong to the Rutaceae family and are known for their juicy pulp and distinctive aroma. They are characterized by a leathery rind and segmented flesh. Citrus fruits encompass a wide variety, including oranges, lemons, limes, grapefruits, and tangerines. These fruits are appreciated for their refreshing taste, high vitamin C content, and versatility in both culinary and non-culinary applications.

Apart from these primary categories, pomology also considers other factors such as tree growth habits (e.g., dwarf, semi-dwarf, standard), fruit-bearing tendencies (e.g., alternate bearing), climatic adaptability, and disease resistance. These categories assist pomologists in understanding and managing the specific requirements of different fruit tree varieties, optimizing their growth and productivity, and ensuring the availability of diverse and high-quality fruits for consumers.

Regardless of the types of trees included in the above categories, the branch of pomology also distinguishes three smaller categories which include the following trees:

Oleacea

Wild olive(Olea europaea var. oleaster or Olea europaea var. Sylvestris)

Jasmine (gen. Jasminum)

Olive (born Olea)

Privet (gen. Ligustrum)

Lilac (gen. Syringa)

South European flowering ash (gen. Fraxinus)

Vitaceae

Vine (gen. Vitis)

Ampelopsis (gen. Ampelopsis)

Virginia creeper (gen. Parthenocissus)

Small Fruiting trees

Strawberry (Fragaria)

Blackberry (Rubus)

Raspberry (Rubus)

Bilberry (Vaccinium)

Hippophaes (Hippophae L.)

Aronia

Goji Berry (Lycium)

Cranberry (Vaccinium)

What is Fruiting Frequency, and why is it important?

Another important factor for categorizing trees is their fruiting frequency. Fruiting frequency refers to the number of times a tree bears fruit within a year. This frequency can be seen once, twice, or multiple times each year. Fruiting in trees is influenced by many factors, such as species, variety, local climate, soil conditions, care practices, availability of water and nutrients, sun exposure, as well as the age of the tree. There is no standardized terminology for this categorization since the exact same variety of lemon trees, for example, can show different fruiting frequencies depending on the geographical location planted. However, it is important to use this characterization on a local scale since this information is of immense importance for farmers who want to decide on tree variety for their orchards. The fruiting frequency of a tree variety will directly influence crop yields and, subsequently, economic yields.

What are the categories of trees according to their fruiting frequency?

Fruiting patterns mainly depend on weather patterns. Trees will exhibit increased fruit production under favorable climate conditions that are long-lasting. For example, the Mediterranean climate allows a large percentage of trees to bear fruit more than once a year. At the same time, the same variety of trees would only be able to fruit once a year in a colder environment such as the one in Northern Europe.

What does ‘single-bearing’ refer to in botany?

• Single-bearing (or single-cropping) trees: This term refers to trees that produce a single crop or set of fruit per year. This is also their main harvest. The production lasts for a specific timeframe before the tree enters a period of dormancy. Single-bearing trees refer to many different species, mostly pomes and drupes, such as apple, pear, and cherry trees. The crop size plays an important role in fruiting frequency since the amount of energy needed by the tree to produce it is increased.

What does ‘twice-bearing’ refer to in botany?

• Twice-bearing (or double-cropping) trees: This term refers to trees that produce two crops or sets of fruit per year. The first harvest occurs during springtime, while the second is during autumn. In the spring months, trees blossom and produce a small number of fruits, while during the autumn months, they produce their main harvest. Twice-bearing trees include many trees, especially citrus trees.

What does ‘multi-bearing’ refer to in botany?

• Multi-bearing (or everbearing) trees: This term refers to trees that have multiple fruiting periods throughout the year, often not tied to specific seasons. In scientific literature, one could come across phrases such as ‘multiple-cropping,’ ‘continuous fruiting,’ ‘prolonged fruiting’, or ‘remontant,’ which all refer to the same behavior. These trees produce fruits at different points on the branches and tips. These fruits are usually smaller in size compared to single-bearing or twice-bearing trees. Examples of such trees include fig, olive, or avocado trees. There is also the concept of ‘indeterminate’ growth, which in botany refers to plants that continue to grow and produce new leaves and flowers throughout their growing season instead of maturing all at once. This could also lead to extended or multiple fruiting periods.

Further reading:

Further reading

Fruit-tree related terminology and categorization – Pomology

The most Popular Lemon Tree Varieties

Lemon Tree Pruning for Optimal Growth and Yield

Nutrient needs and Fertilization of Lemon trees

Important Citrus Diseases caused by Fungi

Important Virus Diseases in Citrus trees

Bacterial Citrus Diseases: Identification and Control