Pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds ...
of
fruit trees
A fruit tree is a tree which bears fruit that is consumed or used by animals and humans — all trees that are flowering plants produce fruit, which are the ripened ovaries of flowers containing one or more seeds. In horticultural usage, t ...
is required to produce seeds with surrounding fruit. It is the process of moving pollen from the
anther
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10
Morphology and terminology
A stamen typically consists of a stalk called the filam ...
to the stigma, either in the same flower or in another flower. Some tree species, including many fruit trees, do not produce fruit from
self-pollination
Self-pollination is a form of pollination in which pollen from the same plant arrives at the Stigma (botany), stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen i ...
, so
pollinizer
{{Unreferenced, date=May 2009
A pollenizer (or polleniser), sometimes pollinizer (or polliniser, see spelling differences) is a plant that provides pollen.
The word '' pollinator'' is often used when ''pollenizer'' is more precise. A pollinato ...
trees are planted in orchards.
The pollination process requires a carrier for the pollen, which can be animal, wind, or human intervention (by
hand-pollination
Hand pollination, also known as mechanical pollination is a technique that can be used to pollinate plants when natural or open pollination is either undesirable or insufficient.
Method
This method of pollination is done by manually transfer ...
or by using a pollen sprayer).
Cross pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, a ...
produces seeds with a different genetic makeup from the parent plants; such seeds may be created deliberately as part of a
selective breeding
Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant mal ...
program for fruit trees with desired attributes. Trees that are cross-pollinated or pollinated via an insect pollinator produce more fruit than trees with flowers that just self-pollinate. In fruit trees, bees are an essential part of the pollination process for the formation of fruit.
Pollination of fruit trees around the world has been highly studied for hundreds of years. Much is known about fruit tree pollination in
temperate climate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...
s, but much less is known about fruit tree pollination in
tropical climate
Tropical climate is the first of the five major climate groups in the Köppen climate classification identified with the letter A. Tropical climates are defined by a monthly average temperature of 18 °C (64.4 °F) or higher in the cool ...
s. Fruits from temperate climates include
apples
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...
,
pear
Pears are fruits produced and consumed around the world, growing on a tree and harvested in the Northern Hemisphere in late summer into October. The pear tree and shrub are a species of genus ''Pyrus'' , in the family Rosaceae, bearing the p ...
s,
plums
A plum is a fruit of some species in ''Prunus'' subg. ''Prunus'.'' Dried plums are called prunes.
History
Plums may have been one of the first fruits domesticated by humans. Three of the most abundantly cultivated species are not found i ...
,
peach
The peach (''Prunus persica'') is a deciduous tree first domesticated and cultivated in Zhejiang province of Eastern China. It bears edible juicy fruits with various characteristics, most called peaches and others (the glossy-skinned, non-fu ...
es,
cherries
A cherry is the fruit of many plants of the genus ''Prunus'', and is a fleshy drupe (stone fruit).
Commercial cherries are obtained from cultivars of several species, such as the sweet ''Prunus avium'' and the sour ''Prunus cerasus''. The nam ...
,
berries
A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...
,
grapes
A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus ''Vitis''. Grapes are a non- climacteric type of fruit, generally occurring in clusters.
The cultivation of grapes began perhaps 8,000 years ago ...
, and nuts which are considered dry fruits. Fruits from tropical climates include
bananas
A banana is an elongated, edible fruit – botanically a berry – produced by several kinds of large herbaceous flowering plants in the genus ''Musa''. In some countries, bananas used for cooking may be called "plantains", distinguis ...
,
pineapples
The pineapple (''Ananas comosus'') is a tropical plant with an edible fruit; it is the most economically significant plant in the family Bromeliaceae. The pineapple is indigenous to South America, where it has been cultivated for many centurie ...
,
papayas
The papaya (, ), papaw, () or pawpaw () is the plant species ''Carica papaya'', one of the 21 accepted species in the genus ''Carica'' of the family Caricaceae. It was first domesticated in Mesoamerica, within modern-day southern Mexico and C ...
,
passion fruit
''Passiflora edulis,'' commonly known as passion fruit, is a vine species of passion flower native to southern Brazil through Paraguay and northern Argentina. It is cultivated commercially in tropical and subtropical areas for its sweet, seedy ...
,
avocado
The avocado (''Persea americana'') is a medium-sized, evergreen tree in the laurel family (Lauraceae). It is native to the Americas and was first domesticated by Mesoamerican tribes more than 5,000 years ago. Then as now it was prized for i ...
,
mango
A mango is an edible stone fruit produced by the tropical tree ''Mangifera indica''. It is believed to have originated in the region between northwestern Myanmar, Bangladesh, and northeastern India. ''M. indica'' has been cultivated in South a ...
, and members of the genus ''
Citrus
''Citrus'' is a genus of flowering plant, flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as Orange (fruit), oranges, Lemon, lemons, grapefruits, pomelos, and lim ...
''.
Temperate fruits
Apples
Most
apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...
plants/trees are
self-incompatible
Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization in sexually reproducing organisms, and thus encourage outcrossing and allogamy. It is contrasted with separation of sexes among individuals ...
, that is, they do not produce fruit when pollinated from a flower of the same tree or from another tree of the same
cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...
, and must be
cross pollinated
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, a ...
. A few are described as "self-fertile" and are capable of self-pollination, although even those tend to carry larger crops when cross pollinated from a suitable
pollenizer
{{Unreferenced, date=May 2009
A pollenizer (or polleniser), sometimes pollinizer (or polliniser, see spelling differences) is a plant that provides pollen.
The word '' pollinator'' is often used when ''pollenizer'' is more precise. A pollinator ...
. A relatively small number of
cultivars
A cultivar is a type of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and when Plant propagation, propagated retain those traits. Methods used to propagate cultivars include: division, root and st ...
are "triploid", meaning that they provide almost no viable pollen for themselves or other apple trees. Apples that can pollinate one another are grouped by the time they flower so cross-pollinators are in bloom at the same time.
Pollination management
Pollination management is the horticultural practices that accomplish or enhance pollination of a crop, to improve yield or quality, by understanding of the particular crop's pollination needs, and by knowledgeable management of pollenizers, p ...
is an important component of apple culture. Before planting, it is important to arrange for pollenizers – varieties of apple or
crabapple
''Malus'' ( or ) is a genus of about 30–55 species of small deciduous trees or shrubs in the family Rosaceae, including the domesticated orchard apple, crab apples, wild apples, and rainberries.
The genus is native plant, native to the temper ...
that provide plentiful, viable and compatible
pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...
. Orchard blocks may alternate rows of compatible varieties, or may plant crabapple
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
s, or
graft
Graft or grafting may refer to:
*Graft (politics), a form of political corruption
*Graft, Netherlands, a village in the municipality of Graft-De Rijp
Science and technology
*Graft (surgery), a surgical procedure
*Grafting, the joining of plant ti ...
on limbs of crabapple. Some varieties produce very little pollen, or the pollen is
sterile
Sterile or sterility may refer to:
*Asepsis, a state of being free from biological contaminants
* Sterile (archaeology), a sediment deposit which contains no evidence of human activity
*Sterilization (microbiology), any process that eliminates or ...
, so these are not good pollenizers. Good-quality nurseries have pollenizer compatibility lists. Growers with old orchard blocks of single
varieties
Variety may refer to:
Arts and entertainment Entertainment formats
* Variety (radio)
* Variety show, in theater and television
Films
* ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont
* ''Variety'' (1935 film), ...
sometimes provide bouquets of crabapple
blossom
In botany, blossoms are the flowers of stone fruit trees (genus ''Prunus'') and of some other plants with a similar appearance that flower profusely for a period of time in spring.
Colloquially, flowers of orange are referred to as such as wel ...
s in
drums
A drum kit (also called a drum set, trap set, or simply drums) is a collection of drums, cymbals, and other Percussion instrument, auxiliary percussion instruments set up to be played by one person. The player (drummer) typically holds a pair o ...
or pails in the orchard for pollenizers. Home growers with a single tree and no other variety in the
neighborhood
A neighbourhood (British English, Irish English, Australian English and Canadian English) or neighborhood (American English; see spelling differences) is a geographically localised community within a larger city, town, suburb or rural area, ...
can do the same on a smaller scale.
During the bloom each season, commercial apple growers usually provide
pollinator
A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains.
Insects are the maj ...
s to carry the pollen.
Honeybee
A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the current cosmo ...
hives
Hives, also known as urticaria, is a kind of skin rash with red, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and does not leave any long-lasti ...
are most commonly used in the United States, and arrangements may be made with a commercial
beekeeper
A beekeeper is a person who keeps honey bees.
Beekeepers are also called honey farmers, apiarists, or less commonly, apiculturists (both from the Latin '' apis'', bee; cf. apiary). The term beekeeper refers to a person who keeps honey bees i ...
who supply hives for a fee. Honeybees of the genus ''Apis'' are the most common pollinator for apple trees, although members of the genera ''
Andrena
''Andrena'' is a genus of bees in the family Andrenidae. With over 1,500 species, it is one of the largest genera of animals. It is a strongly monophyletic group that is difficult to split into more manageable divisions; currently, ''Andrena'' i ...
'', ''
Bombus
A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only extant group in the tribe Bombini, though a few extinct related gener ...
'', ''
Halictus
The genus ''Halictus'' is a large assemblage of bee species in the family Halictidae. The genus is divided into 15 subgenera, some of dubious monophyly, containing over 200 species, primarily in the Northern Hemisphere (a few species occur in So ...
'', and ''
Osmia
Mason bee is a name now commonly used for species of bees in the genus ''Osmia'', of the family Megachilidae. Mason bees are named for their habit of using mud or other "masonry" products in constructing their nests, which are made in naturally ...
'' pollinate apple trees in the wild.
Solitary bee
Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfami ...
s or wild bees such as ground-nesting mining bees (''Andrena'') may play a far bigger role in pollination than at one time suspected, and are alternative pollinators in orchards.
Bumble bee
A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only Extant taxon, extant group in the tribe Bombini, though a few extinct r ...
s are sometimes present in orchards, but not usually in enough quantity to be significant pollinators; in the home garden with only a few trees, their role may be much greater. Apple growers also rely on several species of wild bees for pollination in their orchard.
Increasingly Orchard bees (spring mason bees, genus ''Osmia'') are being used in fruit tree pollination. According to British writer Christopher O'Toole in his book ''The Red Mason Bee'', ''
Osmia rufa
''Osmia bicornis'' (synonym ''Osmia rufa'') is a species of mason bee, and is known as the red mason bee due to its covering of dense gingery hair.O. cornuta'' are used in Europe, while in western North America, the "Blue Orchard Bee" (''
Osmia lignaria
''Osmia lignaria'', commonly known as the orchard mason bee or blue orchard bee, is a megachilid bee that makes nests in reeds and natural holes, creating individual cells for its brood that are separated by mud dividers. Unlike carpenter bees, ...
'', more black than blue in color) is a proven orchard pollinator. In
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
Osmia cornifrons
''Osmia cornifrons'', also known as the horned-face bee, are solitary bees indigenous to Northern Asia. Physically, this species of bee is recognized for its horn-like extensions originating from its lower face. Populations of ''O. cornifrons'' ...
''—provides up to 80% of the apple pollination.
Beyond Japan, ''Osmia cornifrons'' is also used increasingly in the eastern US, because like other mason bees it is up to 100 times more efficient than the honeybee—a mere 600 hornfaced bees being required per hectare, as opposed to tens of thousands of honeybees. Home growers may find these more acceptable in suburban locations because they rarely
sting
Sting may refer to:
* Stinger or sting, a structure of an animal to inject venom, or the injury produced by a stinger
* Irritating hairs or prickles of a stinging plant, or the plant itself
Fictional characters and entities
* Sting (Middle-eart ...
.
Symptoms of inadequate pollination are small and misshapen apples, and slowness to ripen. The
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s can be counted to evaluate pollination. Well-pollinated apples have best quality, and will have seven to ten seeds. Apples with fewer than three seeds will usually not mature and will drop from the trees in the early
summer
Summer is the hottest of the four temperate seasons, occurring after spring and before autumn. At or centred on the summer solstice, the earliest sunrise and latest sunset occurs, daylight hours are longest and dark hours are shortest, wit ...
. Inadequate pollination can result from either a lack of pollinators or pollenizers, or from poor pollinating
weather
Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the ...
at bloom time. Multiple bee visits are usually required to deliver sufficient grains of pollen to accomplish complete pollination.
Pears
Like apples,
pear
Pears are fruits produced and consumed around the world, growing on a tree and harvested in the Northern Hemisphere in late summer into October. The pear tree and shrub are a species of genus ''Pyrus'' , in the family Rosaceae, bearing the p ...
s are self-incompatible and need to attract insects in order to be pollinated and produce fruit. One notable difference from apples is that pear blossoms are much less attractive to honeybees due to their pale coloring and light odor. Bees may abandon the pear blossoms to visit dandelions or a nearby apple orchard. The majority of pollinators of pear trees are
honey bee
A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the current co ...
s, although pears are also visited by
blow flies
The Calliphoridae (commonly known as blow flies, blow-flies, carrion flies, bluebottles, greenbottles, or cluster flies) are a family of insects in the order Diptera, with almost 1,900 known species. The maggot larvae, often used as fishing b ...
and
hoverflies
Hover flies, also called flower flies or syrphid flies, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, whi ...
area of Italy, honeybees could not be used to pollinate pears due to the spread of
fireblight
Fire blight, also written fireblight, is a contagious disease affecting apples, pears, and some other members of the family Rosaceae. It is a serious concern to apple and pear producers. Under optimal conditions, it can destroy an entire orchard ...
in the 1990s, and ''
Osmia cornuta
''Osmia cornuta'', the European orchard bee, is a species of bee in the genus ''Osmia''.
Description
10–15 mm. Males with conspicuously hairy faces. Females are unmistakable due to the black hair on the head and thorax, the rust-red h ...
'' were used as pollinators instead. A way to combat the low attraction of honey bees to pear blossoms is to use bee attractants to entice the bees to pollinate the flowers.Bee attractants may include
pheromones
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...
that mimic the brood pheromone or the juvenile pheromone, or other attractants. There are also other methods for attracting honey bees to pear blossoms. One is
saturation pollination Saturation pollination is a pollination technique for agricultural crops in areas dominated by non-crop plant species that are preferred by pollinators. The technique involves keeping a larger number of bee colonies than normally maintained for hone ...
, that is to stock so many bees that all area blossoms are worked regardless of the attractiveness to the bees. Another method is to delay the movement of the beehives into the orchards until there is about 30 percent bloom. The bees are moved into the orchard during the night and will usually visit the pear blossoms for a few hours until they discover the richer nectar sources. The recommended number of hives per acre is one.
Plums and prunes
Most Asian plums require a second variety for cross-pollination, whereas most European plums are self-fertile. European plums that dry well are also called prunes, the common name for the dry fruit. Several of the Asian plums bloom early and pollinator management is similar to apricots. However the fruiting wood especially of Asian plums can be brittle and over-pollination requires aggressive thinning of fruits.
Apricots
Apricots are botanically similar to
almond
The almond (''Prunus amygdalus'', syn. ''Prunus dulcis'') is a species of tree native to Iran and surrounding countries, including the Levant. The almond is also the name of the edible and widely cultivated seed of this tree. Within the genus ...
s and like almonds they can bloom early, making pollinator management similar except that a tree can overcrop if the fruit is not thinned.
Peaches and Nectarines
Most peaches and nectarines are self fertile and thus require fewer pollinators than apples and pears.
Cherries
Pie cherries, also called sour cherries, are self-fertile. In some varieties, fruit yield could increased by utilizing pollinators. Most sweet cherries need a second variety for pollination, and even self-fertile varies have improved fruit-set with a second variety. Pie cherries can pollinate sweet cherries. Cherries do not need thinning.
Figs
Some figs produce fruit without pollination. Figs that are pollinated rely on
fig wasp
Fig wasps are wasps of the superfamily Chalcidoidea which spend their larval stage inside figs. Most are pollinators but others simply feed off the plant. The non-pollinators belong to several groups within the superfamily Chalcidoidea, while th ...
s.
Temperate nuts
Almonds
The blossoms of most California lmondvarieties are self-incompatible, requiring cross-pollination with other varieties to produce a crop. The single most important factor determining a good yield is pollination during the bloom period. More than a million colonies of honey bees are placed in California Almond orchards at the beginning of the bloom period to pollinate the crop. California beekeepers alone cannot supply this critical need, which is why honey bees travel across the country to the San Joaqin Valley each year. Although the recommended number of hives per acre is 2 to 3, due to the high demand in conjunction with the reduced availability of commercial beehives, many almond growers have to make do with a lower hive density during pollination. These growers started using semiochemical formulations, like SPLAT Bloom, to compensate for the low hive density. SPLAT Bloom manipulates the behavior of the bees, inciting them to spend more time foraging, and thus pollinating flowers in the entire almond orchard (increasing pollination and fruit set), not only close to the hive.
Research into self-fertile almonds has led to the development of several almond varieties that do not need a pollinator tree. Working from an old Spanish variety, "Tuono", researchers in 2008 started making available new self-fertile varieties that more closely match the qualities of the popular "Nonpareil" almond—including varieties "Lone Star" and "Independence". While self-fertile trees do not require pollen from a second tree variety for fruit / nut set, they still depend upon insect pollination for good production. Almond growers with self-fertile almonds report excellent nut set with half (or less) the number of bees in the field.
Wind-pollinated nuts
Hazelnuts (filberts), walnuts, pecans, and chestnuts are all wind-pollinated temperate-zone nuts. Mostly these wind-pollinated nuts are selected varieties that need two different varieties (and favorable winds) for cross-pollination. Insects and birds may visit and consume the pollen, but are not a factor in pollination.
Edible seeds from wind-pollinated coniferous trees such as pine, ginkgo, and monkey-puzzle trees are also harvested and the seeds are colloquially called nuts.
Tropical fruits and nuts
Citrus
Many
citrus
''Citrus'' is a genus of flowering plant, flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as Orange (fruit), oranges, Lemon, lemons, grapefruits, pomelos, and lim ...
cultivars are seedless and are produced
parthenocarpic
In botany and horticulture, parthenocarpy is the natural or artificially induced production of fruit without fertilisation of ovules, which makes the fruit seedless. Stenospermocarpy may also produce apparently seedless fruit, but the seeds are ac ...
ally without pollination. Some cultivars may be capable of producing fruit either way, having seeds in the segments, if pollinated, and no seeds if not. Citrus that requires pollination may be self-compatible, thus
pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...
must be moved only a short distance from the
anther
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10
Morphology and terminology
A stamen typically consists of a stalk called the filam ...
to the stigma by a pollinator. Some citrus, such as
Meyer Lemon
''Citrus'' × ''meyeri'', the Meyer lemon (), is a hybrid citrus fruit native to China. It is a cross between a citron and a mandarin/pomelo hybrid.
Mature trees are around tall with dark green shiny leaves. The flowers are white with a purpl ...
s, are popular container plants. When these bloom indoors, they often suffer from blossom drop because no pollinators have access.
Hand pollination
Hand pollination, also known as mechanical pollination is a technique that can be used to pollinate plants when natural or open pollination is either undesirable or insufficient.
Method
This method of pollination is done by manually transfer ...
by a human pollinator is a solution.
A few citrus, including some
tangelo
The tangelo ( , ; ''C. reticulata × C. maxima'' or ''× C. paradisi''), ''Citrus × tangelo, is'' a citrus fruit hybrid of a ''Citrus reticulata'' variety, such as mandarin orange or tangerine, and a ''Citrus maxima'' variety, such as a pomel ...
s and
tangerine
The tangerine is a type of citrus fruit that is orange in color. Its scientific name varies. It has been treated as a separate species under the name ''Citrus tangerina'' or ''Citrus'' × ''tangerina'', or treated as a variety of ''Citrus retic ...
s, are self-incompatible, and require cross pollination. Pollinizers must be planned when groves are planted. Managed honeybee hives at bloom time are often used to ensure adequate pollination.
Papayas
Passion fruit
Most edible passion fruit varieties are self fertile. Since each flower is only open for 1–2 days and may not get the chance to be pollinated by insects, fruit set can improved by hand pollinating.
Avocados
Mangoes
Mangoes are usually self pollinating and also grown by grafting
Fruit tree pollination
Pollination of fruit trees is required to produce seeds with surrounding fruit. It is the process of moving pollen from the anther to the stigma, either in the same flower or in another flower. Some tree species, including many fruit trees, do no ...