APPLE (Pyrus malus Linn.)
Introduction
and Importance
The cultivated apple (Malus domestica Borkh ) is reported to have originated in
the temperate region of western Asia, between Black sea and Caspian sea. Apple
is a symbol of health, beauty and love. This fruit has universal cultivation and
worldwide consumption in many forms. In Pakistan, various forms of apple showing
great diversity in size, shape, colour and taste are grown from the time
immemorial, particularly at high elevations (About 1300 m) in the areas
adjoining Afghanistan, Iran and China. Most of the developed varieties have been
introduced during the British period. The total area, reported under apples in
Pakistan is about 45875 hectares with an annual production of 589281 tonnes
(1998-99).
The cultivated varieties of apples presently grown in Pakistan have been given the name as Pyrus malus Linn. These are grafted on the rootstock Pyrus baccata (Crab apple).
Apple is a very nutritious, aromatic and delicious fruit. It is very rich in Vitamin C, B and A. It contains about 11% sugar besides essential minerals in appreciable amounts. It has colour appeal, appetite and is most refreshing. It can be used in many different ways. It is cooked, made into preserves, Jellies, candied, canned, prepared as fresh apple juice, made into cider or vinegar. The peel is used for making pectin.
Inspite of some serious pests and disease problem there is an increasing trend for bringing more area under apple because of better returns.
Production
Technology
Climate: Most of the commercially grown
apple cultivars in Pakistan requires a cooler climate than all other fruits.
Apple thrives and fruits best under a relatively cool slow growing season,
usually met with at higher altitudes. Therefore, proper selection of varieties
is of major importance. Varieties grown under such conditions are Amri, Kashmiri
Amri, Golden Delicious, Red Delicious, Sky spur, Banki, Kulu etc. Low chilling
varieties such as Anna, Summer Gold and Golden Dorset have been identified
giving encouraging results and hence can successfully be grown in lower
elevations.
Rainfall
is also an important factor associated with fruit production especially for high
chill varieties where no other source of irrigation is available. An annual
rainfall between 25 to 30 inches evenly distributed throughout the year is most
desirable. In low rainfall areas best production can be achieved by
supplementing irrigation water.
Soil: Although apple tree grows and bears fruit in a wide range of soil, the most suitable appears to be deep rich, well drained fertile loam soil. The soils should be free from hard substrata and waterlogging conditions.
Propagation: Apple plants are raised on the seedlings/suckers rootstock which are more adaptable to the soil and climatic conditions. The rootstocks are grafted with desired scion variety during December-January. Usually tounge or cleft grafting gives a good success and is performed about 20-30 cms above ground level. T budding at the onset of monsoon rains is also practiced.
Planning
and Planting: While planting an orchard, proper decisions regarding
selection of varieties, rootstocks, tree size and spacing, pollination and
planting procedures must be made with understanding. Planting distance varies
according to variety, vigour of rootstock, the fertility level of the soil and
general climatic conditions of the area. Most often planting is done in square
system. However, on slopes contour planting should be preferred.
Fertilizer Requirements: Application of manures and fertilizers start right from the planting of orchard and the first application is made at the time of filling of pits. In an orchard of average fertility, NP and K may be applied in the ratio of 70:35:70 grams per year age of the tree respectively and the dose may be stabilized after 10 years (700:350:700 g of NPK per tree). These applications may be supplemented by FYM at 10 kg per year age of the tree. The increase or decrease in the fertilizer doses may be regulated on the basis of fertility status report of the soil and plants.
Irrigation: Apple orchards at high elevations are largely dependent on natural rainfall. A greater part of the apple growing season in this region gets regular precipitation except in May-June. During these months some arrangements should be made for irrigation water because this period coincides with natural fruit drops which can be lessened if trees are supplemented with irrigation. In Quetta region there is no rainfall during summer hence irrigation should be applied after 10 days to young plants and 15 days in case of mature and bearing trees.
Pruning:
The pruning of apple is often ignored by many orchardists, mainly because they
are unaware of the objectives of this practice. Young non-bearing apple trees
are prunned to train or shape them in such a way that a strong framework
consisting of stout limbs is built to support maximum crops of fruit without
breakage. Prunning of bearing trees is practiced to keep the tree tops low so as
to facilitate thinning, spraying, picking, to make the trees well opened for
penetration of sun light which in turn promotes better quality and colour of the
fruit and to remove weak, diseased and undiseasable branches. Best time of
pruning is late dormant season because it will eliminate the severe injury from
extremely low winter temperature and heal up the cuts quickly.
Harvesting,
Packing And Storage
Fruits should be harvested at proper picking maturity. The time of picking will
depend upon the degree of maturity which in turn depends upon the keeping
quality of the fruit. Apples picked at immature stage results in poor quality
and flavour, tend to shrivel and are subject to physiological disorders such as
scald, bitter pit, soft and brown core. Fruits do not mature evenly on the tree,
therefore, more than one pickings are required. Avoid bruising and stem
punctures. Picking should start from lower branches of a tree advancing towards
the top. After picking apples should be put under cover in the coolest, well
ventilated place. Apples may be packed in wooden crate, card board boxes,
cartons or in film bags. Before packing the fruit should be graded according to
size and exterior quality of the apple. The length of post harvest life during
storage will depend upon the stage of maturation at harvest time, the length of
the fruit remains at ordinary storage temperature and at cold temperature,
season of picking and the variety itself.
Insects and Diseases
Apple Tree Borer (Apriona cinerea)
Larva of the beetle is limiting factor in the production of apples in Swat and
Azad Kashmir. After hactching the grubs start boring into the shoots from the
top and make long galleries downward which reach the main stem in big trees and
root portion of the young tree.
Control: Phosphatic insecticides are put in the hole which kill the larvae.
Sanjose
Scale (Aspidiotus pernicious)
This pest attacks pome and stone fruits and nuts. They suck cell sap and passes
winter as nymphal stage. The infected plant turn pale and flowers are shed.
Control: After fruit formation spray Lorsban.
Wholly
Apids. (Eriosoma ganigerum)
White wool is seen on the twigs. The pest suck the cell scap. Infected part of
the plant are dried. Remains active during summer.
Control: Lorsban or Karate should be sprayed
Codling
Moth
This is fruit borer and is very destructive. The adult lay eggs on the calyx end
of the fruit. Larvae enters the fruit and eat the flesh. After feeding it fall
to the ground.
Control:
Tarcol bands are made on the trunk to prevent larvae crawling to the tree.
Remove old bark
Spray Lorsban at small fruits
Distruction of larvae and pupae from the soil and around trees.
Powdery
Mildew
This is a fungal disease and appears on new leaves and fruits in form of white
powdery deposits which hinders normal photosynthesis process. The infected
leaves turn pale, twisted and fruit stops growth.
Control:
Spray fungicide like Benlate, Dithene M-45, Topsin-M etc. at dorment stage or at bud break.
Another spray at the petal fall stage is needed.
Apple
Scab
The newly emerged leaves and fruits have black irregular spots. The infected
fruit looks ugly and remains stunted and rot in the storage.
Control: Spray before bud break Dithene M-45, Captan, Topsin-M
etc.