Peaches (Prunus persica)

  1. Introduction

Common names: English: Nectarine

The peach tree is native to China and belongs to the family Rosaceae. It is a deciduous tree growing to 4 – 10 m tall with well branched crown. It is the least hardy of the temperate fruits. The fruits are 3 cm – 8 cm diameter, round and fleshy, greenish at first and ripen to yellow-red. The skin of some varieties is covered with short hairs that rub off but nectarine a sub species of peach is hairless. The seeds are deeply pitted and furrowed. Peaches are a good source of Vitamin A and C, potassium and iron.

  1. Cultivars

In Kenya, locally selected cultivars like Waldo, Killiecrankie, Alexander and Jewel have been supplemented by the importation of cultivars like Neethling, Kakamas, Texas, Culemborg, and Floridagold.

144       Fruit Production Technical Handbook                                                                                 Peaches

 

Table 14.1: Varieties

Name Description
Killiecrankie The tree is a robust grower
and prolific  bearer. Fruits are
round to oval and medium to
large in size.
The skin is mainly yellow with
a fine red shade when mature.
The flesh is creamy white to
yellow, sweet, and of good
quality.
Flordagold The tree is vigorous but
rounded and compact in
growth with strong branches.
It is very productive and
requires heavy thinning to
improve fruit size.
The fruits are yellow-fleshed,
semi-clingstone type, firm and
of medium to large size. The
shape is round oblong with
near equal halves.
At maturity, 60% of the fruit
surface is red over a bright
yellow back ground.
Flordaprince The tree is vigorous, with semi
upright growth. The external
surface of fruits is red blush with
yellow colour. Average yield is up
to 100kg per tree. The fruit ripens
early and is semi-clingstone
cultivar.
Fruit flesh is yellow and firm with
some red colouring near the
peel.

 

Name Description
Flordaking An early maturing variety that
requires just 70 days from full
bloom to maturity.
The fruit has a red-blushed skin and
golden yellow flesh that is juicy and
pleasantly sweet.
Kakamas The tree is vigorous with a
spreading growth habit and its
chilling requirements are medium.
It produces heavily and regularly.
Fruits are round to ovate with a
point and a marked suture.
Skin and flesh colour ripens to a
dull golden yellow.
It can be stored for 2 weeks at
0.5 °C. It has outstanding canning
qualities but seed residues may be
a problem.
Neethling It is a vigorous tree with a
spreading growth and low chilling
requirements.
The fruit is round with yellow skin.
The flesh has a good taste and a
non-melting, fine and firm texture.
Its canning quality is good.
Sunred A semi-freestone cultivar with small
to medium-sized fruit that is round
without a suture, bulge or beak.
The external blush is bright red,
covering most of the fruit.
The flesh is yellow, firm and of
excellent flavour.

146       Fruit Production Technical Handbook                                                                                 Peaches

 

  1. Ecological requirements

Altitude

Most suitable altitude is 1,200 m – 2,500 m a.s.l. At higher altitudes, temperatures are too low for the production of good quality fruits, and ‘leaf curl’ disease may be prevalent. At low altitude the crop will not fruit.

Rainfall

Peaches require adequate rainfall of 800 mm – 1000 mm per year. In case of low rainfall irrigation is necessary.

Soils

Peaches can be grown on a wide variety of soils provided they are well drained on the upper soil profile, i.e. from 1.2 m – 1.8 m. They do best in fairly deep sandy loam soils, with a pH of 6.0 – 6.5 and good drainage. The tree can tolerate clays and gravel soils provided they are deep and well drained.

Temperature

Peaches require sufficiently low day and night temperatures to break the dormancy. Optimum temperatures are 6 0C – 8 0C; however chemicals such as Dormex (hydro-gen cyanamide) can be used to break dormancy. Very low temperatures of – 20 0C injure fruit buds. Temperatures of 2 0C – 3 0C during bloom may result in blossom injury of up to 90%.

  1. Agronomic practices

Land preparation

Proper site selection and cultivar choice rank as two important factors in successful peach growing.

The land should be cleared of vegetative material and ploughing done. Planting holes should be dug 60 cm x 60 cm x 60 cm deep before the rains.

Spacing

The holes should be spaced at 5 m x 6 m or 6 m x 7 m depending on the cultivar. The top soil should be separated from the sub-soil. The top soil should then be mixed with 20 Kg of manure and put back into hole.

Propagation

Peaches can be propagated vegetatively or by seed. The cultivars are generally propagated by budding which can be done 5-6 months after germination. T-budding should be used and the best success is with buds from new growth. Seeds should be viable and stratified at 40 0C for 3 – 4 months before planting.

Planting

Peaches are planted as bare- root seedlings when dormant, or from pots or polybags during the growing season. The seedling should be planted at the centre of the hole to allow adequate spread of roots.

All common peach cultivars are self-pollinating and thus trees should be planted in solid blocks for easier spraying and picking.

Fertilizer application

CAN should be applied at the rate of 0.5Kg/year/tree multiplied by the tree age in year’s up to a maximum of 3Kg/tree/year e.g. 1st year; 0.5 x 1= 0.5 Kg; 2nd year 0.5 x 2=1 Kg. This should be done during the long rains and distributed evenly under the branch spread.

Weed control

Cultivate lightly to control weed competition especially in the first year of growth. Or-chards under grass should be mowed or sprayed with herbicides; straw mulch also helps control weeds.

Pruning

Peaches are pruned more heavily than any other temperate fruit trees. The tree is pruned and trained to an open centre to facilitate the penetration of light and cir-culation of air. This takes 2 – 3 years following which the trees should be ready to bear fruits. Peach trees produce fruit on one-year-old wood only, so they should be pruned annually to remove old wood and allow new growth to develop for the fol-lowing year’s crop. Thus, the terminal and lateral shoots which have developed over the outer surface of the tree are the most important for fruit production. The best and most fruits are produced on the upper third of the tree.

Formative pruning

  • At planting, the central shoot is cut to 1 m above ground.
  • Remove broken branches, those near the ground and those with narrow crotch angles with the main trunk. The latter easily break off from the tree during fruit bearing period.
  • During the second season (2nd year), select 2 – 3 branches which are equal in size, having wide crotch angles and uniformly distributed around the trunk. These branches form the main scaffold branches (framework of the tree).
  • Remove all other undesirable branches.

Rejuvenative pruning

Rejuvenative pruning is done to revive trees in decline. The tree is severely cut back so as to allow the dormant buds to develop. 

Thinning

Thinning is used to control the number of fruits per tree in order to increase fruit size and quality as well as to ensure adequate vegetative growth. It is recommended that fruits should be thinned within 4 – 6 weeks after bloom or after the natural shading has taken place. Thin the fruits leaving one every 20 – 25 cm along the branch.

  1. Pests and Diseases

Table 14.2: Pests

Pest Symptoms Control
Sucking aphids Poor fruit set, curled, distorted leaves, Use recommended
(Myzus persicae) and dieback of tender young shoots. insecticides e.g. Decis
2.5EC,Duduthrin 1.7EC
Codling moth Eggs deposition on ripening fruits and Remove and bury
(Cydia pomonella) the hatching caterpillars penetrate infected fruits Eradicate
into the pulp. Infested fruit will drop host plants e.g. wild
prematurely. castor.
Fruit flies Small, white, legless maggots on the Use recommended
(Cydia molesta) rotting pulp of ripening fruits. insecticides e.g.
Duduthrin 1.7EC,
Confidor 70WG
when there is severe
Infestation
Table 14.3: Diseases
Disease Symptoms Control
Scab

Small brown spots on the fruit skin. Use recommended
(Cladosporium fungicides e.g. Copper
spp) The centre’s of the spots become Oxychloride
brown and corky, and deformation or
splitting of attacked fruits follows.
Mildew Infection starts as white, felty patches Use resistance varieties
(Podosphaera ssp.) especially at the leaf margin, later Use recommended
extending over the whole leaf surface fungicides e.g.
and down over the entire shoot. Bayleton WP25, Nimrod
Young infected leaves and shoots are 25EC, Cosavet DF
stunted and often die back.
Disease Symptoms Control
Leaf curl The disease appears soon after leaf Use recommended
(Taphrina emergence with the developing fungicides e.g. Copper
deformans) leaves showing yellow areas which based fungicides,
become dark red, thick and wrinkled. Daconil 720SC
Infected leaves fall prematurely and
young shoots become distorted and
die.
Peach Rust

Cankers develop after petal fall on Use resistant varieties
1-year-old fruiting wood. They appear Use recommended
as blisters and longitudinal splits in fungicides e.g. Amistar
the bark. The lesions appear as bright Top 325SC, Cupravit.
yellow, angular spots on the upper
surface of leaves. Early and severe
defoliation also may reduce yields
and stimulate the production of new
leaves and buds late in the growing
season. They first develop as small,
brownish spots with green halos on
mature, yellow fruit. The lesions are
sunken and extend into the fruit.
Armillaria root

Infected peach trees wilt suddenly Remove the infected
rot and die. plants in the affected
(Armillaria mellea) Cutting through the bark at the base area followed by wound
of the trunk will reveal the fungus as a paint treatment.
thin white strip.
Anthracnose Small chlorotic spots appear on the Pruning of dead
(Colletotrichum fruit surface. The spots gradually branches and twigs
spp) enlarge and become noticeable Use recommended fun-
as circular, sunken, tan lesions on gicides e.g copper based
ripening fruit. fungicides.
The sunken lesions have a glistening
or slimy surface.
  1. Harvesting

A fully productive orchard (about 9 – 12 years old) can produce around 15 tons/ ha. Under optimal growing conditions and good husbandry 25 – 30 tons per Ha can be achieved. Peaches begin bearing a commercial crop in their 3rd or 4th year and reach full production at 9 – 12 years of age. The trees have a life span of 15 – 20 years. Care should be taken when harvesting since the flesh is very tender and prone to damage. Fruits should be picked when nearly mature and firm. Peaches do not ripen uniformly on the tree and it is therefore necessary to carry out several picking operations at 2 day intervals. Ripe fruits will readily detach from the tree with a slight twist.

Post harvest management

The fruits will not keep for long under room temperature and should be kept in a cool place. The fruits may be stored for 1 – 2 weeks at 10 0C after harvesting. Boxes lined with cotton prevent the skin from damage.

  1. Utilization

Peaches are consumed fresh or processed into jams, juices and nectars.

  1. Marketing

The fruits are marketed locally.