Permeating irrigation involves placing a plastic tube between the rows
40 cm (16 inches) below the soil surface.Tiny holes are made in the tubes.A water containment
area is established beside a plot of fruit trees to which the tubes are connected.No machines or
electricity are needed.
Thinningof Flowers and Fruits
Thinning of flowers and fruits is conducted more carefully in China than in other countries.In
general, flower thinning by hand begins at the pink bud stage.Fruit thinning is usually
conducted twice, in mid-May and early June.There is quite a good understanding of fruit
thinning in China, with consideration given to ecological conditions, tree vigor, tree age, trunk
thickness, nutrient area, structure of trees and distribution of fruits.To determine a proper load,
thinning practices have proven successful in some orchards after several years’ experience.
1) determine the cropload per unit land according
to the cultivar, density, age and management level; 2) determine the average yield per tree and
adjust by trunk thickness (medium to vigorous tree 0.4 kg/cm2); 3) determine the number of
fruits which should remain according to the weight per fruit; 4) add 10% more fruit in case of
accidental drops; 5) determine the distance between fruits according to flower amount and
distribution; 6) make proper adjustment among individual trees.
Measures to Improve Flower Bud Formation
In China, apple trees usually grow too strongly because of vigorous rootstocks and the
unfavorable climate (severe drought in spring and extensive rain in late summer and early
autumn).Therefore, it is necessary for growers to apply great effort to induce sufficient flower
bud formation every year to keep the trees bearing normally.The main measures used include:
1) little pruning when trees are young; 2) training branches horizontally as early as possible;
3) girdling the trunk or limbs; 4) spraying or root-feeding growth inhibitors (e.g., PP333) or
flower-inducing agents; 5) judicious management of soil, fertilization and irrigation;
6) controlling diseases and pests perfectly; 7) summer pruning to adjust accumulation and
distribution of nutrients.
Growth Regulator
Many growth regulators are used extensively in apple production.Four of special importance
are:1) Promalin and auxin plus gibberellin-like substances which are used to increase
longitudinal growth of a fruit; 2) root-inducing products (ABT Rooting Powder series No. 1-5)
which are used in planting or transplanting young trees; 3) PP333 which is used for controlling
tree growth in high-density orchards; 4) auxin and auxin-like substances which are used for
inducing dormant bud break.
Bagging
Fruit bagging with paper bags has had a long history in pear growing and in recent years the
techniques have been applied to apples.The use of bagging has increased to supply international
market needs and to increase grower income.Several paper-bag factories have been established
in the main apple-growing regions and many kinds of bags for different cultivars and districts
have been developed.With bagging, fruit appearance has been improved greatly and sprays have
been reduced.
regions.The trees used for bagging should be healthy, of medium vigor and have a good supply
of flower buds.It is important to thin surplus flowers and young fruits as early as possible and to
allow only one fruit per cluster.Insecticides and fungicides are applied 1 or 2 days before
bagging.Fruit are bagged 35 to 50 days after flower abscission.Leaves on spurs and bourse
shoots around the fruit are removed 5 to 7 days before removing the bags to improve light
penetration to the fruits.Total defoliation is between 30 and 60%.Outer bags are removed
1 month before harvest and the inner bag 3 to 5 days later.After defoliation and bag removal,
reflective film mulching is placed under the trees and fruits are turned to expose the green side of
the fruit to light.
Winter Injury to Young Trees
In northern China, freezing and drying injuries are great threats to 1 to 3-year-old trees.Drying
causes excessive losses every year.Drying injury is physiological drought which happens when
a water balance between absorption and transpiration cannot be maintained.Some preventive
measures have been used with young trees to reduce drying:1) control late-stage growth by
reducing irrigation and nitrogen application; 2) spray growth inhibitors or use pinching to stop
tree growth in late autumn; 3) apply enough water before the soil freezes; 4) make an earth
mound around the southwest side of a tree; 5) whitewash the trunk, crotch and sometimes part of
the central leader before freezing; 6) mulch around a tree with plastic film in winter; 7) paint
with protective substances such as methyl cellulose and polymeric ethyl alcohol.
Establishingan Orchard
In China, establishment of an orchard to a high standard has been advocated for many years.The
main recommendations include:1) select the desired cultivar and proper rootstock (usually
seedlings ofMalus baccataorM. macromalusor interstems of M.26 on the seedlings); 2) choose
Extra or First-class grafted trees which have been in the nursery for over 2 years and, if possible,
use virus-free dwarf trees; 3) improve the soil thoroughly by digging a deep ditch and filling with
manure and weathered soil; 4) soak root systems in water for at least 24 hours before planting,
use proper root pruning, and dip in a solution of root-inducing powder; 5) plant trees to avoid
being either too shallow or too deep; 6) irrigate the trees immediately after planting and mulch
with plastic film around each tree; 7) head back and cover the whip with a long, narrow plastic
bag to reduce evaporation; the bag is removed when new growth is about 5 cm (2 inches) in
length.
vigorous rootstocks, 4 to 6 m (13.1 to 19.7 feet) with vigorous rootstocks if tractors are used and
2 to 4 m (6.5 to 13.1 feet) with dwarfing rootstocks or interstocks.Spacing within rows is
usually 2 to 3 m (6.6 to 9.8 ft).
Training and Pruning
A great change has taken place in training and pruning of apple trees in recent years, as growers
move to higher density plantings.The main training systems used are slender spindle for dwarf
trees and free spindle for standard trees although, in some cases, small canopy central leader
systems are also used.
Many measures for summer pruning
and training have been used:scoring above buds, ringing, spreading in the growing season to
pinching, twisting, pruning to thin out and remove water sprouts, girdling, widening angles of
scaffold branches by supporting, pulling down and hanging weights, and shoot softening.
Softening is damaging a shoot from base to apex by bending and twisting several times but not
breaking.
IMPROVEMENT OF GROWING PRACTICES
The techniques used in apple production which play an important role in increasing yield and
quality have been improved in recent years.
(compact trees) systems is a major feature in the overall reform in cultural practices.With high-
density planting, training and pruning are greatly simplified with comprehensive management of
soil, fertilization and irrigation.New training systems with small canopies and simple structures
have shortened the training time compared with the past.Together with effective measures to
hasten flower bud formation and to control the canopy growth, the time from planting to bearing
has been shortened.Early production occurs in the third year after planting, with full production
in the fifth year, and the unit output, under good care, can attain production of 15 to 26 MT/ha.
standpoint of producing top-quality fruit.After the introduction of Fuji apples into China,
inferior coloration and poor fruit finish were obvious in some districts at low elevation and
latitude.The inferior fruit could not compete in the marketplace.In recent years, the apple
project team at the Agricultural University of Hebei has made systematic studies of many factors
which influence fruit quality.Based on the climatic characteristics in lower-latitude regions in
central Hebei, they proposed a set of cultural techniques by which the extra-fancy fruits can be
produced with overall red color and attractive appearance comparable to those produced in
Japan.The techniques were listed above under bagging.It can be predicted that fruit quality
will be raised soon with the popularization of these techniques.
PROBLEMS
Lower Yieldper Unit Land Area
Although the total output of apples in China has ranked first in the world and the yield will
increase undoubtedly with time, a marked difference exists between China and more developed
countries in productive efficiency per unit of land (Table 2).The yield of apples from some
advanced countries ranges from 20 to 35 MT/ha, e.g., France 32 MT/ha, New Zealand 34 MT/ha,
Italy 29 MT/ha and US 25 MT/ha.The average yield in China, however, is much lower.In
China there are small differences among provinces, e.g., Liaoning 4.48 MT/ha, Shandong
4.39 MT/ha, Henan 3.55 MT/ha, and Shaanxi 3.24 MT/ha.
In China, the level of management varies
with different farmers and orchards.It is possible that yield could reach 37.5 to 45 MT/ha in
some Fuji plantings, and 40 MT/ha or so in some Starkrimson Delicious plantings.These
orchards will play an important role in teaching other growers.It is reasonable to assume that
one of the shortcuts to narrow the difference between high- and low-yield orchards is to
popularize the existing experience.
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