From the 1986 Journal of the California Rare Fruit Growers
DESCRIBING MANGO VARIETIES
San Diego, California 92120
Most agricultural crops can trace the early efforts of domesticating wild species to amateur undertakings. The identification of superior selections is an essential part of attracting a more intense phase of study and experimentation which can result in the successful clonal propagation of plants having commercial potential.
The accurate description of plant growth, flowering and fruiting characteristics allows each horticulturist to communicate about the plants being studied without the reader having to physically view a plant specimen.
Mr. S. R. Gangolly developed concepts for the nomenclature and classification of mango in his Master of Science thesis at the University of Madras in India. The following major features provide the horticulturist with an opportunity to describe mangos:
1. VEGETATIVE CHARACTERISTICS
Tree Shape or Form.
The silhouette of a tree is commonly expressed in the literature with terms such as tall, medium and dwarf. The value of this description is questionable without quantitative data correlated to numerical terms. Cultural care, soils and climatic conditions can influence normal growth patterns. A description of the original tree at specific ages can vary widely from subsequent clonally propagated trees. Even clonally propagated trees may differ within an orchard and between orchards in different climate zones.
The shape of a typical adult-bearing age mango tree in good health and exhibiting normal growth can provide a basis to describe distinctive groups.
A. Oval Shape: The spread is much smaller than the height.
B. Round Shape: The spread and height are almost equal.
C. Dome Shape: The spread is much wider than the height.
The attachment angle of the leaf is distinctive in some mango varieties.
A. Upright or Erect: The angle is less than 45 degrees.
B. Spreading: The angle is between 60 and 80 degrees.
C. Drooping or Downward: The angle is greater than 100 degrees.
Shape of Leaf.
The leaf shape is a distinctive varietal characteristic in mangos. There are three elements used to describe leaf shape.
A. Mango leaves are lance-shaped. The term lanceolate is used to describe this type of leaf; however, this leaf type can be divided into three sub-classes.
(1) Elliptic-Lanceolate: The leaf is very narrow from the leaf base to leaf tip.
(2) Ovate-Lanceolate: The widest portion of the leaf is nearest the leaf base.
(3) OvaI-Lanceolate: The widest portion of the leaf is halfway between the base and the leaf tip.
B. The leaf margins may have distinctive forms which can be described.
(1) Flat: The leaf midrib and leaf margin are flat.
(2) Crinkled: The leaf is 'puckered' between the midrib and leaf margin.
(3) Twisted: The midrib is twisted into a spiral.
(4) Wavy: The leaf margin is wavy, but the midrib is straight.
(5) Folded: The midrib is straight. The leaf margin curves upwards to form a boat-like shape. The degree of divergence from flat is divided into two groups.
(a) Slightly Folded
(b) Strongly Folded
C. Shape of Leaf Tip. There are three leaf classifications of leaf tips.
(1) Acute: A blunt point.
(2) Acuminate: A sharp point with a long, drawn-out tip.
(3) Sub-Acuminate: Intermediate between Acute and Acuminate.
D. Leaf Thickness.
F. Odor of Crushed Leaves.
F. Color of Mature Leaves.
Leaf thickness and color of mature leaves are extremely variable within a variety due to vigor of the tree growth caused by external factors such as soil moisture, fertility and climate.
2. FLORAL CHARACTERISTIES
A. Shape of Panicle. The flower inflorescence usually consists of a panicle with 50 or more male and a smaller number of perfect flowers.
(1) Conical Panicles: The length of the main axis of the panicle greatly exceeds the width (spread).
(2) Pyramidal Panicle: The width (spread) of the base of the panicle is roughly equal to the length. The width (spread) tapers from the base to the tip of the panicle.
B. Size of Panlcle. Mango varieties can be distinguished by the length and width (spread) of the panicle if measurements are provided as an index.
C. Hairiness of Panicle. The appearance of the panicle can be a diagnostic toc~ if a reliable measurement index was established. Terms like glabrate, sparsely puberulent, moderately puberulent and densely puberulent have not been standardized to obtain the same appraisal from different evaluators.
D. Color of Panicle. A standard color index can be used to describe the color of the panicle, but the color can vary on a tree depending on the exposure of the branch to climatic influences.
F. Size of Stamens and Pistil. Many varieties differ in the relative size of stamens and ~stil to one another.
(1) Long Stamens: The stamens are longer than the pistil.
(2) Equal Stamens: The stamens and pistil are equal in length.
(3) Short Stamens: The stamens are shorter than the pistil.
F. Relative Position of Stamens and Pistil.
G. Proportion of Perfect Flowers. The percentage of perfect flowers to staminate flowers can vary from season to season and may vary from panicle to panicle on an individual tree within a season. This is not considered a reliable diagnostic tool.
3. FRUIT CHARACTERISTICS
The goal of the grower is to produce high-quality fruit. It is no surprise that most of the efforts to describe the mango should be based on the various factors that relate to physical fruit qualities.
The external physical characteristics of fruit representative of the variety or seedling can be described by measuring the width and height of the fruit and classifying the various parts of the fruit.
A. Major Diameter. This is a side view of the fruit which provides a view of the following parts:
(1) Ventral Shoulder
(2) Dorsal Shoulder
B. Minor Diameter
The external physical characteristics of the stone (seed encased in a fibrous husk) representative of the variety or seedling can be described by measuring the width and height of the husk and describing the amount and location of the attached fiber.
The amount of fiber contained in the fruit flesh can be measured. The usual descriptions are:
(1) Fiberless. The most desirable fruit.
(2) Almost Fiberless. Accepted by most new mango consumers.
(3) Some Fiber. Accepted by many consumers familiar with mangos.
(4) Moderate Fiber. Accepted by mango devotees. Usually grown only in home gardens.
(5) Very Fibrous. No commercial importance. Usually discarded unless it has some beneficial genes for plant breeding.
EXAMPLES OF MANGO FRUIT AND SEED HUSK WITH ATTACHED FIBER
The most subjective description of any fruit relates to the flavor, taste and aroma of fruit in various stages of ripeness. Obviously the maturity of the fruit when it is harvested will have an effect on the chemical changes which occur in the ripening process. Mangos with traces of a turpentine taste would be considered unacceptable by most mainstream American consumers trying a mango for the first time.
Varieties selected for commercial production must have qualities that will provide consumer satisfaction when harvested at a specific degree of maturity that allows for a reasonable length of time in cool storage, transportation, in produce-department displays and by the consumer prior to consumption.
It is possible to measure and describe various horticultural qualities not previously mentioned. The following topics have commercial and home gardening importance:
1. Salt tolerance
2. Cold tolerance
3. Disease resistance
4. Insect resistance
6. Drought tolerance
8. Accumulated heat units to mature fruit
A. Length of harvest in weeks
B. Months of expected harvest
10. Dwarf rootstock
The positive identification of plant materials can be achieved with lab tests. This is an expensive and time-consuming process. The horticultural description of varieties provides a method of evaluation of the performance of a specific clone, but can not be relied upon to identify separate plants of similar physical appearances.
A comprehensive discussion on the subject of evolving a standard system of nomenclature and classification can be obtained by consulting "A Monograph on Classification and Nomenclature of South Indian Mangos" by K.C. Naik and S.R. Gangolly, published by Government Press, Madras, India in 1950.