Everything you need to know about growing cherry! Learn about: 1. Botany of Cherry 2. Climate and Soil Required for Growing Cherry 3. Orchard Cultural Practices 4. Planting Operation 5. Cultivation 6. Propagation and Rootstocks 7. Flowering and Fruiting 8. Pollination and Fruit-Setting 9. Training and Pruning 10. Harvesting and Handling.
Botany of Cherry:
Cherries belong to the family Rosaceae, genus Prunus and subgenus Cerasus. Prunus avium and Prunus cerasus are the two most important commercial species.
Sweet Cherry:
It is a tall tree with strong central leader, bark red-brown, scaling is transverse strips. Leaves usually oblong-ovate to oblong-obovate, gradually taper pointed, blade 10-15 cm long, soft in texture, hanging limp on the young growths, margins doubly acute- glandular-serrate at first but becoming more or less obtuse-serrate, the petiole usually bearing one or more large glands near top.
Flowers white about 3 cm across, appearing with the first leaves from clusters of buds on lateral spurs, the inner glandular bud-scales large and persistent for a time, on glabrous pedicels about 3 cm long, calyx tube constricted near top, the lobes entire. Fruit is globular or heart shaped, yellow or red with mostly sweet flesh.
On the basis of the texture of flesh, sweet cherries have been divided into two pomological groups i.e. Heart and Bigarreau. The Heart Cherry cultivars have soft and tender flesh and heart-shaped fruits. The fruit colour varies from dark with reddish juice to light coloured with colourless juice. The Bigarreau group are usually roundish, may be more or less heart-shaped. The colour of fruit and juice also varies from dark to light red. Cherry fruit is drupe and its edible portion is edicarp and mesocarp.
Sour Cherry:
The tree is usually 6-9 m tall, open headed, round topped or spreading and often without a central leader. The branches are slender and more or less drooping. Fruit is 2 cm in diameter, roundish-oblate or cordate with slightly compressed sides. Leaves are much smaller and darker green in colour. The commonly grown cultivars are more hardy than sweet cherry.
Climate and Soil Required for Growing Cherry:
The sour cherry can tolerate more cold than sweet cherry. In the nursery stage sweet cherry suffered more bud damage at – 25 to – 33°C as compared to sour cherry. In the orchard also the sweet cherry suffer more from frost than sour cherry. Sour cherry requires 15°C mean temperature during the growing period and do not thrive well in warm climate.
The sweet cherry is badly damaged at both severe cold and warm climate. Sweet cherries are well adapted to an elevation. 1500 – 2500 MSL. It require 1000 – 1500 hr. chilling period during winter. Climatic conditions of Kashmir and high hills of Himachal Pradesh are ideal for commercial growing of sweet cherry. Always select frost free site for cherry as it is badly damaged by spring frosts. Hill slop is a preferable site where the cold air may drain down. The trees grown on the southern aspect on low elevations may suffer from drought in May-June.
The southern aspect at higher elevations proves beneficial. An annual rainfall of 100 – 120 cm well distributed throughout the year is desirable. Heavy rains at the time of flowering and towards the ripening period cause heavy damage. Rain at flowering time results in blossom wilt as the spores of wilt enters through the stigma of the opened flowers. Fruit cracking is common due to rain at the time of fruit ripening. The fruits become under sized and shrivelled due to high transpiration rate.
The cherry grow better on soil having high level of fertility. It gives better performance on well-drained warm, deep, free-working and sandy loam soils. Soil should be able to hold sufficient water for 15-20 days during the period of high water requirement. Cherries do not tolerate wet feet; therefore, water-logged soils should be avoided. Planting of Cherris in clay soils should be avoided.
Orchard Cultural Practices for Growing Cherry:
i. Irrigation:
The water need of cherries is more during spring and early summer. During growth and development period of fruit, the plants need irrigation at weekly interval. The rains start from middle of June and continue up to mid-September. Only, one irrigation after the rainy season is sufficient. Overwatering in cherries is not desirable as the plant is very sensitive to wet feet. The provision of drainage of excess rain water should be made. The average yield in sweet cherry increased when it is irrigated before and during fruit ripening. Its tree produce 20 per cent higher yield when irrigated at 80-85 per cent soil moisture level.
ii. Manuring and Fertilization:
The application of 150 g Nitrogen for every 2.5 cm girth of the plant is recommended in Himachal Pradesh. The fertilizer should be applied in early spring at about 2-3 weeks before bloom in a 60 cm wide land under the canopy of the plant. As most of the roots are at depths of 11-40 cm, placement of fertilizer and tillage should be shallow. In Himachal Pradesh, 500 g nitrogen, 250 g phosphorus and 650 g potassium is added to a ten year old plant of cherry. FYM, phosphorus and potash should be applied in December. Half nitrogen is applied in spring before flowering and the other half one month later.
Application of 600 g N, 300 g P2O5 and 900 g K2O is recommended for 15 years old plants of sweet cherry in Kashmir Valley. Total phosphorus and potassium and half nitrogen is applied 2 weeks before expected bloom and remaining half of nitrogen 3 weeks after fruit-set.
Zinc deficiency symptoms in cherries are noticed. Small, narrow, chlorotic leaves are produced which are at usually distorted or wavy. Foliar spray of zinc sulphate at 2.5 kg in 100 litres of water in early spring at 2-3 years interval may correct its deficiency.
iii. Mulching and Weed Control:
Clean basin management is a most common method of floor management in sweet cherry plantation in Himachal Pradesh. Most of the cherry orchards are maintained under permanent sod with a clean basin management. Mulching in the tree basins with 10-15 thick hay in April helps to conserve soil moisture and also control the weed growth. To improve the fertility level and soil texture, green manuring in the tree basins is very useful practice. The crops like bean, pea, red clover and white clover are good for green manuring. Pre-emergence herbicide Diuron @ 4 kg/ha or post-emergence herbicide paraquat @ 5//ha can check for weed flora for 4-5 months in sweet cherry orchards.
Planting Operation for Cherry:
While planting, there should not be hard pan or big stone either below or on its sides which may restrict the development of the roots. The pit for cherry plantation should be 1 x 1 x 1 x m dimension. The pit may be filled with a mixture of top soil and farmyard manure in 1:1 ratio. All the broken or injured roots should be cut off and treat the cut portion with fungicide. In areas where winter is not too severe, planting may be done in early winter, so that the root system is well established before the opening of the buds in spring. The planting of cherries may be delayed to late winter in the areas having severe winter.
The distance between the trees should vary from 9-12 metres, in this way 75-123 plants per hectare will be accommodated. In vigorous rootstock F 12/1 and in Mazzard seedlings, the distance should be kept 12 metres. The distance in Mahaleb seedling should be 9 metres.
The cherry tree remains in a profitable condition for over 60 years. It is also recommended that orchard of sweet cherry should be planted 6 x 6 m apart by square or hexagonal system in Kashmir Valley and Himachal Pradesh.
Cherry Cultivation:
Cherry is a perishable fruit. Its cultivation in India is very limited and is confined mostly to Kashmir. There are two types of cherries, the sweet cherry (Prunus avium) and the sour cherry (Prunus cerasus), which is used for canning or cooking. They require a climate similar to that for apple. Most commercial varieties of cherry are self-incompatible and some are even cross-incompatible.
In establishing a cherry orchard the varieties planted should be able to pollinate one another. Sweet cherry is generally propagated by whip grafting on seedlings of wild cherry called Paja (Prunus puddum). The grafts are ready for transplanting within two years. Grafting in situ is also practiced.
Cherry trees are affected by sunscald. They are, therefore, planted on, slopes where the sun is not too strong and the trees are kept low headed. The planting distance is 10 to 13 metres.
The trees require staking immediately after planting. The cherry orchard can be successfully managed by sod culture. It requires very little pruning. The fruit, which is borne in clusters on long stems, should not be harvested when wet. If it rains, when the fruits are ripening, the fruits crack and rot.
The cherry tree starts bearing from the fifth year and reaches full bearing after 10 years. It continues to bear up to the age of 50 years. Fruit-thinning is not practiced. The yield is low, being about 10 kg per tree. The fruit is packed in small baskets in Kulu and in wooden boxes containing 5 to 10 kg in Kashmir.
Most of the commercially successful cherry varieties in India have a light colour and firm flesh. These belong to the Bigarreau group, which includes sweet cherries with firm flesh and colourless juice. Early Amber or Pink Early, Frogmore, and Governor Wood are such early varieties. Double Heart, which is probably Napoleon, is important in Kashmir. Senecca is the earliest black cherry of the Heart group and Early Rivers also belongs to the same group.
Propagation and Rootstocks of Cherry:
The cherries are propagated by stooling, cutting, budding and grafting. Budding or grafting is done on the seedlings or vegetatively propagated rootstocks. The cherries are mostly grafted on the seedlings of Prunus cerasoides or Prunus avium or Stockton morello (Prunus cerasus).
Vegetative Propagation:
i. Stooling:
In Spring, the mother plant is cut back at the ground level before sprouting. When the shoots attain 25-30 cm length, their bases are covered with a mound of soil or sawdust building the mound to a height of 20-30 cm. Roots arise from the bases of the shoots and grow into the mound. Treating the ringed portion of F 12/1 rootstock with 7500 ppm IBA during summer, cent per cent rooting can be obtained.
The mound is kept moist throughout the summer. The shoots normally become well-rooted by the winter and are transplanted in the nursery rows for a year to produce strong plants for budding or grafting. Suckers of Prunus mahaleb and Prunus avium are removed during winter. When the suckers attained thickness of 0.6 cm in diameter, then they can be grafted or budded during the next spring.
ii. Cutting:
Hardwood stem cuttings are made between late fall to early spring. The cuttings can be treated with 100 ppm IBA for 24 hours to obtain higher success. Semi hard wood cuttings are leafy and are usually taken during mid or late summer.
Colt rootstock is easy to root and can be easily multiplied through cuttings. Hard-wood cuttings are prepared in February and treated with IBA 2500 ppm for 10 seconds and planted in the nursery beds for rooting. These are grafted with desired scion variety in March.
iii. Budding and Grafting:
Budding is done after the sap flow started i.e. from the last week of April to the last week of May. T-budding gives higher per cent success. For grafting, the scion wood is collected during the winter when the buds are dormant. Cleft grafting is considered the best method which is performed during February-March.
Rootstocks:
The most common rootstock in Kashmir, Himachal Pradesh and Kumaon hills of Uttarakhand is Paja (Prunus cerasoides var. Majestic) seedlings. Colt (a semi dwarfing rootstock) Primus avium x Prunus pseudocerasus) is used in Kashmir. The old plantations are found on Mazzard (Prunus avium) or Mahaleb (Prunus mahaleb) rootstocks. The wild cherry Prunus paddum (bird cherry) found growing wild in Shimla hills and adjoining areas is also sometimes used as a rootstock. The Paja rootstock has been observed to show delayed incompatibility with commercial cultivars of sweet cherry.
The plants of cherry on Paja make good growth during the first 8-9 years, then start showing signs of ill-health, decline and completely decline or die after 14-15 years. In Himachal Pradesh, Paja rootstock has now been dispensed with and the clonal rootstock Colt and Mazzard F 12/1 are recommended. Colt is compatible with most of the sweet cherry varieties. It has good charge and resistant to gummosis and crown rot.
Mazzard F12/1 is a semi-vigorous rootstock. The cherry performance on Prunus cornuta is also studied. It is a vigorous and deciduous species growing wild in the Himalayan ranges between elevation of 2140 and 3060 metres. The graft success of cherry cv. Emperor Francis was 93 per cent on Prunus cerasoides and 63 per cent on Prunus cornuta. However, the average linear growth of the grafts was 95 cm on Prunus cornuta compared to 41 cm on Prunus cerasoides.
Flowering and Fruiting in Cherry Trees:
The sweet cherries grafted on vigorous rootstocks like F 12/1 take about eight years to come in commercial bearing. The flowers of cherry appear laterally on one year old spurs and shoots. The spur elongates in almost a straight line for several successive years because the terminal bud is a leaf bud. The flowers of sweet cherries are bisexual and hypogynous.
The growth of cherry fruits follows a double sigmoidal curve i.e. there are three stages of fruit development. In stage first, the epidermal fruit cells increase in number and size rapidly. In second stage, the growth slows down, and thereafter increases tremendously in the stage third.
Pollination and Fruit-Setting of Cherry:
A large number of cherries are self-unfruitful and thus do not set crops with their own pollen they need cross-pollination. The cherries are also cross-incompatible with some other commercial varieties. Thus, only the compatible varieties can be inter-planted to get commercial crops. The compatible varieties to be grown should be those whose periods of flowering sufficiently overlap, to effect cross-pollination. Stella which is a self-fruitful variety should preferably be used in the combinations of other varieties.
The other donor varieties like Vista, Vic, Senecca and Vega can be planted with any variety to get good fruit set. It is important that their flowering period must overlaps with main varieties. Honey bee usually carries the pollen grains from the anthers of one cultivar to the stigma of another cultivar. In case of sour cherries, yield is increased to an average of 67.8 per cent by planting self-fertile cultivars compared with 13.4 per cent in self-incompatible cultivars.
Open pollination gives adequate fruit set for a commercial crop in cherries which ranges from 7-50 per cent depending upon cultivar, climate and management practices being followed. Frequent and high rainfall and low temperature during flowering often interferes pollination which can be overcome by increasing the number of bee-hives in cherry orchards. GA3 200 ppm + DPU (diphenyl urea) 300 ppm + NOXA 50 ppm or NAA 10 ppm or 2, 4, 5 TP 10 ppm applied in spring increased fruit number in sweet cherry. Paclobutrazol @ 0.8 g in an area of 2 x 2 metre weed free soil under each tree of cv. Early River of sweet cherry in March increased fruit size and yield considerably.
Training and Pruning of Cherry:
Training of Young Trees:
Sweet cherry plants should be trained to central modified leader system. The plant is headed back at 90-100 cm at the time of planting. The wide angled scaffold branches should be kept 20-25 cm and located spirally around the main stem. While forming a well-shaped tree, the selected scaffold branches should be headed back minimum to have a good balance between them and the leader. During second year, the central leader is retained and all the other upright branches should be removed by cutting close to the trunk.
At this time only 3-5 wide angled main branches at 20-25 cm distance and spirally around the tree are retained. The lower scaffold branches may be kept 50 cm above ground. During pre-bearing period, scaffold should be headed back only when they grow very long and willowy and when it is desirable to have secondary shoots. The leader is cut back when the trees grows larger just close to a suitable outward growing branch.
Pruning of Bearing Trees:
Pruning in bearing trees is done with a view to remove week and unnecessary branches. The centre of bearing tree should be kept open. In sweet cherry, fruit is borne laterally on spur which arise on one year old shoots. The spurs grow less than 2.5 cm in a year with a terminal leaf bud. The productive life of the spurs is 10-12 years in sweet cherry. As compared to sour cherry, less renewal wood is needed in sweet cherry. As such 10 per cent of fruit bearing area should be removed annually.
In sour cherry, 10-20 cm long annual shoot growth is sufficient in full grown bearing trees. The fruit buds in this cherry are produced laterally on one year old terminal growth. The fruiting spurs are produced on 2-3 year old vigorous shoots. Most of the crop is borne on the periphery of the tree. Therefore, the pruning in some cherries should comprise thinning out of long branches. Pruning in cherries should be done late in season after growth has started as the danger of infection by silver leaf disease is then minimised.
Harvesting and Handling of Cherries:
In cherries, the stage of maturity for harvesting is of great importance in maintaining consumer acceptance. The harvesting of cherries before maturity results in flat fruits and less yield as its fruit usually make rapid development during the last few days before full maturity is reached. The cherries should not be allowed to overripe on the trees which results in loss of weight and volume.
The colour development of fruit is the best guide, though it varies with the cultivar and the purpose for which the fruit will be used. Total soluble solids of fruit is an another reliable index of fruit maturity. The taste of fruit may also guide the time of picking. Fruits of sweet cherries picked earlier do not taste well. The fruit picked late may be either very sweet or insipid. The fruit picked at right stage of maturity have better size, colour, general appearance, taste, flavour, firmness and sugar-acid blend.
Sweet cherry varieties can be picked on the basis of number of days taken from full bloom to maturity. The fruits of Black Heart require 52-58 days, Guigne Noir Hative 54-60 days, Bigarreau Napolean 65-68 days and Bigarreau Noir Grossa 69-74 days from full bloom to maturity. The fruit of different varieties ripens from third week of May to second week of June in Kashmir.
The fruit of cherry is picked by hand for which labour is required. The sweet cherry is picked with the stems unless they are to be delivered for processing. Pulling the cherries from the supporting stems causes a slight wound. The fruit can be artificially ripened by spraying 400 ppm ethephon two weeks before harvesting. Sour cherry used for processing is picked by pulling or stripping the fruits from the stems leaving the latter on the trees. Ethrel is used by some growers to collect fruits by shaking the trees.
The yield of sweet cherry is extremely variable from year to year. Sweet cherry trees grow larger than sour cherry and bear heavily. A good yield of 6.3 to 9 tonnes or more per hectare is obtained from standard trees. The mean yield of high yielding cultivars is recorded as high as 13 to 21 tonnes per hectare (57-92 kg per tree). The average yield is 15-20 kg per fruits per tree. The fruits are packed in 5 kg CFB boxes for better marketing.
Storage:
To reduce losses from rotting and poor quality, rapid cooling of fruits immediately after picking is recommended. A hydro-cooling can be used in the orchard. The shelf life of cherry fruits can be extended by spraying 30-50 ppm GA3 in the orchard before harvesting. Post-harvest dipping of fruits in 40 g per litre solution of calcium chloride for 2 hours at ambient temperature (20°C) maintained fruit firmnes after 30 days of storage. The storage life of sweet cherry is 18 days in normal temperature (0°C and 85% RH) and 30 days in controlled atmosphere (8% carbon dioxide + 5% oxygen). Some cherries can be stored for 15 days at 0-2°C and 24 days at 5% CO2 + 3% O2.