Temprate Fruits (1+1)

CULTURAL PRACTICES

Orchard floor and weed management

• Weeds if allowed to grow in the orchard exhausts nutrients and moisture from soil. Thus it is suggested that apple orchard should be managed as clean basin management system.
• In this system, the basin of trees are kept clean and free from weeds either by hand weeding, use of mulches and weedicides.
• In the initial years of plantation, the intercrops like peas, beans, cabbage, cauliflower and ginger are grown in the vacant area in between the trees but not in basin area.
• Some green manuring crops like bean, peas and gram can also be grown which helps in improving soil texture and nutrient status.
• In bearing orchard, mulching of basin area of trees with 10 cm thick layers of hay or black alkathene is a good floor management practice for efficient weed control and insitu moisture conservation.
• Sod grasses like white clover, red clover, orchard grass and rye grass are grown in the vacant area between the trees.
• For herbicidal weed control , pre-emergence and post emergence weedicides can also be used. Spray of simazine at the rate of 4 kg/ha in March, followed by two sprays of glyphosate @ 800 ml/ha at monthly intervals in July and August have been found very effective to control the weeds in apple orchards.

Irrigation

• Apple require optimum soil moisture particularly during the period of fruit growth and development to get good size and better quality fruits.
• The cultivation of apple in India is mainly in hilly areas, where land is sloppy and water for irrigation is also inadequate. Moreover, in these areas rainfall is also very less or no rainfall occurs particularly during critical period of growth.
• The most critical periods of water requirement is April to July, when flowering, fruit set , fruit growth and development occurs.
• Therefore, water management is very important in apple orchards Water management includes rainwater harvesting, in-situ soil moisture conservation and efficient use of water for irrigation through drip irrigation.
• The rain water should be harvested and collected in water storage tanks. The harvested water should be used for irrigation particularly during critical periods of water requirement.
• Drip irrigation method saves more than 50 per cent irrigation water and can be adopted in water scarce areas.
• About 6-8 irrigations at 7-10 days interval should be given during April to July in Apple.
• Besides irrigation,tree basins should be mulched with hay or black polythene in the month of March.

Fruit Thinning

• Heavy bearing in apple during on year, results in small sized and poor quality fruits. Therefore, judicious thinning at proper stage of fruit development (pea stage) is must to regulate cropping and improving fruit size and quality.
• The thinning can be achieved either manually or with the use of growth regulators.
• Removal of fruit lets by hand thinning is very laborious and uneconomical, therefore chemical thinning with foliar spray of 20 ppm Nepthalene acetic acid (NAA)at petal fall results in optimum fruit thinning

Fruit Drop

• Although apple bloom profusely, yet a small percentage of flower will mature into fruit.
• Most of the flowers fall soon after full boom with small amount dropping later. Fruit drop is a serious problem in apple.
• In most of the commercial varieties 40 to 60 per cent fruit drop occurs in three phases.
• Early Drop is a natural and occurs due to lack of pollination after petal fall to three weeks later. This drop can be controlled by assuring effective pollination and placement of bee hives and planting of more pollinizer varieties in the orchard.
• The June Drop is a major drop which is caused by moisture stress. This drop can be controlled with the application of irrigation water and mulching of tree basins.
• The Pre-Harvest Drop occurs before harvesting of fruits and caused economic loss to farmers, which is due to reduction in levels of auxins and increase in ethylene in the fruit. Application of 10 ppm NAA 20-25 days before harvest checks this drop.

Use of growth regulators:
Growth regulators plays a significant role in breaking seed dormancy and improving seed germination, rooting in cuttings of clonal rootstocks, flowering fruit set, vegetative growth, fruit size and shape, colour development, ripening and abscission and control of fruit drop in apple. The role of these growth regulators are broadly described as:

1. Plant propagation: Growth regulators help in breaking seed dormancy and initiation of rooting in cuttings of clonal rootstocks. GA3 at 100-200 ppm can overcome the physiological dormancy and stimulate germination in seeds. Application of IBA at 2000 ppm and NAA @200 ppm helps in rooting in cuttings of clonal rootstocks.
2. Effect on growth: Growth regulators like auxin and GA3 helps in increasing the vegetative growth, growth retardants like PP333 retard the growth of trees and help in flower bud formation. Foliar spray of PP333 @ 500 to 1000 ppm reduces the vegetative growth of apple trees. Application of 250 ppm GA3 stimulate the vegetative growth but also enhances alternate bearing phenomenon.
3. Effect on fruit set and yield: In apple there is a problem of fruit setting in marginal and warm areas. Application of triacontanol (20 ppm), miraculan (0.6 ml/L), Paras 0.6 ml/L or Biozyme at 2ml/ L sprayed at bud swell and petal fall stages helps in improving fruit set and yield in Delicious apple.
4. Fruit drop: The problem of pre-harvest fruit drop is more severe in early maturing cultivars, where 40-60% of fruit drops. The pre-harvest dropping is mainly because of hormonal imbalance and can be controlled with the application of 10 ppm NAA, (1 ml of Planofix in 4.5 L of water) one week before the expected fruit drop.
5. Fruit thinning: Many cultivars like Red Gold , Starking Delicious and Golden Delicious are prone to bear heavily resulting in smaller, low quality fruits thus promote biennial bearing cycle. The application of 10-20 ppm NAA, 7-15 days after petal fall is most effective for fruit thinning and to maintain regular production of good size and quality fruits.
6. Improvement of fruit shape: In apple market price depends upon the size and shape having well developed calyx lobes especially in Delicious Group apples. Application of promalin 30-60 ppm (GA3+7 + cytokinin) at pea stage helps to improves the shape of the apple fruits.
7. Improvement of fruit colour and maturity: Apple surface colour development is greatly hampered in low lying apple growing areas due to warmer conditions. Fruits with poor colour fetch low prices. Application of ethrel (2- chloro ethyl phosphonic acid) @ 1200 ppm a..i. or 4.5 ml ethrel/ litre of water + 25 ppm NAA improves surface red colour in apple.

Maturity indices and Harvesting

• Apple is a climacteric fruit in which the maturity of fruit does not coincide with ripening.
• The fruits do not attain ripe edible quality on the tree at harvest. If the fruits are picked immature, these fruits lack flavour and taste, which shrivel in storage.
• The harvesting of over mature fruit develops soft scald and internal breakdown and has poor shelf life.
• To judge the optimum harvesting time several maturity indices are adopted.
• The maturity indices like days from full bloom to harvest, change of ground colour of fruit from green to yellow to pale, TSS of fruit pulp, ease of separation of fruit from spur, change of seed colour to light brown and fruit firmness are used singly or in combination.
• The entire fruit does not attain full colour and mature on the tree at one time, therefore, fruits should be picked in 2-3 pickings.
• Harvesting of fruit is done in such a way that bruising and stem puncture are avoided and pedicel must retain with fruit.
• Fruits of apple are grasped between index finger, middle finger and thumb and quick twist of wrist will easily pluck the fruit along with pedicel.
• Picked fruits are placed softly in the picking bag or basket and transported to packing houses for grading and packing.

PRE- AND POST-HARVEST MANAGEMENT

• After harvesting of fruits, proper handling, grading and storage is important. In apple fruits, about 30% post harvest losses have been recorded, which can be minimized by proper handling of fruits.

(a) Precooling:-

• Immediately after picking, the fruits should be placed in a cool and ventilated place for removal of field heat before packing.
• For the removal of field heat, the methods like use of air cooler, cold water sprinkling, fruit washing and keeping of fruits over night in a cool place are adopted.

(b) Grading:-
The fruits are graded according to fruit size and fruit appearance like colour and shape. On the basis of size, the apple fruits are graded manually or by mechanical grades as:

• On the bases of fruit colour shape, quality and appearance fruits are graded as AAA, AA, and A.
• The quality of fruits during transportation, storage and marketing are influenced by the packing. Usually, apples are packed in telescopic corrugated fibre board (CFB) cartons.
• The usual dimensions of telescopic CFB carton with trays are 50.4 x 30.3 x 28.2 cm (outer jacket) 50 x 30 x 28.2 cm (inner case).
• The each layer of fruit in carton is separated by a fruit trays which are different for different size grades.

(c) Storage

• Apple fruit has long storage life and shelf life of fruits can be prolonged by providing optimal storage conditions.
• The cold storage retards fruit deterioration and reduce decay from pathogen and to prevent shrivel ness resulting from water loss.
• Apple fruits can be stored for 4-6 months after harvest in cold storage at a temperature of -1.1 to 0 oC with 80-90 per cent relative humidity.

(d) Processing

• About 30 per cent of apple fruits are rejected as cull fruits before packaging for fresh fruit market.
• The culled fruits can be processed and preserved as fruit pulp for making various value added products like jam, fruit leather, fruit toffees and fermented products like wine can be prepared from preserved pulp.
• From fresh fruit juice can be made.