Fruitfulness and Pollination

I came across this article and it mays help some new fruit tree growers to have a clearer picture of pollination requirement.

To better select fruit for planting, growers should
become familiar with the terms used to describe
pollination characteristics and fruitfulness of different
fruit types. Some of the most basic terms that
need to be understood are pollination, self-pollination,
cross-pollination, self-fruitful, cross-fruitful,
parthenocarpic, and perfect-flowered.
Pollination refers only to the transfer of pollen
from the anthers (male structure) of one flower to
the stigma (female structure) of the same or another
flower. The processes of pollination and subsequent
seed formation are generally necessary for
fruit set and development of most fruit plants.
Self-pollination occurs when flowers are pollinated
by pollen within the same horticultural variety
from the same or different trees. Most peach
varieties, such as Redhaven, are fruitful when selfpollinated
and therefore can be planted in very
large blocks without using a second variety.
Cross-pollination occurs when flowers of one
variety are pollinated by pollen from a second variety.
For example, Golden Delicious varieties are
often used in apple orchards to cross-pollinate Red
Delicious varieties.
Self-fruitful implies that a single variety of a
given fruit type will produce satisfactory fruit crops
when grown by itself. This may occur because the
variety is self-pollinating (such as peach) or because
they are parthenocarpic (such as some persimmons,
figs, and satsumas).
Cross-fruitful implies that cross-pollination is
required among two or more varieties to produce
satisfactory crops. Red Delicious apple varieties, for
example, are cross-fruitful when cross-pollinated
with varieties of Golden Delicious.
Parthenocarpic basically means fruit are produced
without complete seed development, resulting
in seedless fruits. Satsuma, for example, has
sterile pollen, mostly nonviable ovules, and is highly
parthenocarpic, which results in the production
of seedless fruit.
Perfect-flowered means that flowers of that
variety have functional male and female parts.
Carlos is a perfect-flowered muscadine grape that is
self-fruitful and is used as a pollinator for female
type varieties such as Fry.
Pollination and fruiting characteristics of fruit
plants are described in Table 1.
Whether a fruit type is self-fruitful or requires
cross-pollination influences how varieties are
arranged in a planting. For self-fruitful plants, single
varieties perform well when planted alone. For fruit
types requiring cross pollination, two or more varieties
of each type should be planted. Planting entire
rows with the same variety makes management
of cultural practices and harvesting much easier
and more cost effective. When only the minimum
number of pollinators is desired, a pollinator variety
should be planted as every third plant in every
third row.
Insects, especially bees, are essential pollinators of most fruit plants,
such as rabbiteye blueberries shown here.
Arlie Powell, Extension Horticulturist, Professor, David
Himelrick, Extension Horticulturist, Professor, William
Dozier, Professor, and David Williams, Extension
Horticulturist, Associate Professor, all in Horticulture at
Auburn University
For more information, call your county Extension office.
Look in your telephone directory under your county’s name to
find the number.
Issued in furtherance of Cooperative Extension work in agriculture and
home economics, Acts of May 8 and June 30, 1914, and other related
acts, in cooperation with the U.S. Department of Agriculture. The
Alabama Cooperative Extension System (Alabama A&M University and
Auburn University) offers educational programs, materials, and equal
opportunity employment to all people without regard to race, color,
national origin, religion, sex, age, veteran status, or disability.
UPS, 9.1M16, New March 1999, ANR-53-E
Visit our Web site at: www.acesag.auburn.edu
1
Apple
Pear
Asian pear
Peach
Nectarine
Quince
Plum
Cherry, sweet
Cherry, sour
Oriental persimmon,
astringent
Oriental persimmon,
nonastringent
Pomegranate
Fig, common
Cross-pollinating
Cross-pollinating
Cross-pollinating
Self-fruiting
Self-fruiting
Self-fruiting
Cross-pollinating
Cross-pollinating
Self-fruiting
Self-fruiting
Self-fruiting or
cross-pollinating
Self-fruiting
Self-fruiting
Plant two or more varieties of each type for cross-pollination.
Golden Delicious apple varieties tend to be at least partially selffruitful
when planted alone.
Use a second variety every two to four rows. Plant only two to
three rows of the same variety.
Some varieties appear partially self-fruitful, but a minimum of two
varieties should be used.
Plant two or more varieties of each type for cross-pollination.
Exceptions to this general rule are Methley, Homeside, and AU
Producer plums, which are generally self-fruitful.
Sweet cherries are not recommended in Alabama because of
freeze problems. Pollination requirements are also very exacting.
Montmorency sour cherry is self-fruitful.
Nonastringent persimmon varieties, such as Fuyu, are self-fruiting
but can shed excessively and may require the use of pollinators,
such as Gailey, to ensure full cropping.
Table 1. Pollination and Fruiting Characteristics of Fruit Types
Fruit Type Characteristic Description
Tree Fruit
Bunch grape
Muscadine grape,
perfect-flowered
Muscadine grape, female
Blackberry
Raspberry
Blueberry, rabbiteye,
highbush, and southern
highbush
Strawberry
Self-fruiting
Self-fruiting
Cross-pollinating
Self-fruiting
Self-fruiting
Cross-pollinating
Self-fruiting
Female muscadine grape varieties must be planted with perfect
types for cropping.
Two or more varieties of the same type, such as rabbiteye,
must be planted for cross-pollination.
Rabbiteye blueberries generally fruit best when a varietal
sequence of two to one is used across the planting, such as two
rows of Tifblue and one row of Premier.
Highbush blueberry varieties are more self-fruitful but usually
benefit from interplanting two or more varieties.
A few of the varieties available, such as Apollo, require crosspollination.
Subtropical and Exotic Fruit
Satsuma
Kumquat
Meyer lemon
Kiwifruit
Feijoa
Self-fruiting
Self-fruiting
Self-fruiting
Cross-pollinating
Cross-pollinating
Kiwifruit have male and female varieties that must be interplanted
to ensure cropping. One male is used for every five to ten female
plants.

http://www.aces.edu/pubs/docs/A/ANR-0053-E/ANR-0053-E.pdf

Tony

One interesting point about parthenocarpy missing from this is that (I believe) many pear varieties are capable of it, apparently, depending on the conditions AFTER bloom. Warm clear days provide a kind of energy surplus that encourages the pears not to jettison unpollinated and seedless fruit. I read in Childers classic fruit growing book that years ago, when such orchards existed, commercial Bartlett orchards in S. CA often didn’t include any other variety of pear, so dependable was the parthenocarpic crop.

This is probably one thing that leads to confusion about whether certain varieties of pears are self fruitful or not. If the weather is good in early spring many pears will not only bear some fruit, but will bear a full crop without cross pollination or any pollination at all.

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