Download Aonla Aonla or Indian gooseberry (Emblica officinalis) is an

Aonla
Aonla or Indian gooseberry (Emblica officinalis) is an indigenous fruit to Indian
subcontinent. Owing to hardy nature, suitability to various waste-lands, high
productivity/unit area (15–20t/ha), nutritive and therapeutic value aonla have become an
important fruit.
Its fruits are a rich source of vitamin ‘C’. Aonla fruit is highly valued among indigenous
medicines. It is acrid, cooling, refrigerant, diuretic and laxative. Dried fruits have been
reported to be useful in haemorrhages, diarrhoea, dysentery, anaemia, jaundice, dyspepsia
and cough. Trifla and chavanprash are well-known indigenous medicines in Ayurvedic
system using aonla. Besides fruits, leaves, bark and even seeds are being used for various
purposes.
Its cultivation is common in India, particularly in Uttar Pradesh comprising Pratapgarh,
Rai Bareilly, Varanasi, Jaunpur, Sultanpur, Kanpur, Agra and Mathura. Its intensive
plantation is being done in the salt-affected areas of Uttar Pradesh, including ravinous
areas in Agra, Mathura, Etawah, Fatehpur and semi-arid tract of Bundelkhand. Aonla
cultivation is also spreading rapidly in the semi-arid regions of Maharashtra, Gujarat,
Rajasthan, Andhra Pradesh, Karnataka, Tamil Nadu, Aravali ranges in Haryana and
Kandi area in Punjab, Himachal Pradesh extending to Ghar area in Uttar Pradesh.
Climate and soil
Aonla is a subtropical plant and prefers dry subtropical climate. Heavy frost during
winter is not conducive to its cultivation. A mature aonla tree can tolerate freezing as well
as high temperature of 46°C. Warm temperature seems conducive for the initiation of
floral buds. Ample humidity is essential for initiation of fruit growth of dormant fruitlets
during July–August. Dry spells result in heavy dropping and delay in initiation of fruit
growth.
Since aonla is a hardy plant, it can be successfully grown in variable soil conditions. The
deep root system, reduced foliage, dormancy of fertilized fruitlets (April–June) makes
aonla an ideal plant for arid and semi-arid conditions. Aonla can be cultivated in marginal
soils—slightly acidic to saline/sodic (pH 6.5–9.5) conditions. Heavy soils or high
watertable areas are not suited for its cultivation.
Varieties
There are 3 main varieties of aonla—Banarasi, Francis (Hathijhool) and Chakaiya. These
varieties have their own merits and demerits. Banarasi, an early-maturing aonla, is a shybearing, prone to heavy dropping of fruits with poor shelf- life. Francis suffers from
severe incidence of fruit necrosis. Chakaiya fruits are fibrous, smaller in size and also
have a tendency to bear heavy crop in alternate years. Other varieties identified and
released for commercial cultivation are:
Kanchan (NA 4)
A seedling selection from Chakaiya, it is heavy and regular bearer (7.7 female
flowers/branchlet), with medium-sized fruits, having higher fibre content. It is preferred
by industries for pulp extraction and manufacturing of various products. This has been
adopted very well in the semi-arid regions of Gujarat and Maharashtra.
NA 6
A seedling selection from Chakaiya, it is prolific and heavy-beared (10.8 female
flowers/branchlet). It is ideal for preserve and candy, owing to low fibre content.
NA 7
A seedling selection of Francis, it is precocious, prolific and regular-bearer (9.7 female
flowers/branchlet). This is an ideal variety for preparation of products and has a great
promise.
Besides, Anand 1, Anand 2 and Anand 3 have been selected as promising strains in
Gujarat.
Propagation and Rootstock
Aonla has long been raised through seeds and inarching. From seed propagation, there is
prolonged juvenility and wide variability. On the other hand only limited number of scion
shoots are available for inarching owing to upright tree habit.
It can be successfully propagated through patch/modified ring budding in north India
during mid-May to September with 60–100% success. Besides, Veneer grafting also has
successfully been attempted. Considering the efficiency and requirement of single bud,
budding is an ideal method of propagation.
Six months to one-year-old seedlings obtained from ‘desi’ aonla tree are being used as
rootstock. Mature aonla fruits are collected during January–February and their seeds are
extracted after drying. Seeds are sown in raised beds April onwards and these are
transplanted in separate bed for subsequent budding.
Propagation of aonla in polybag, polytube, ‘‘root trainer’’ or in-situ orchards needs to be
standardized and commercialized.
Mosambi
Citrus fruits rank third in area and production after banana and mango in India and
sweet orange are the second largest citrus fruits being cultivated. Sweet orange growing
states are Andhra Pradesh, Maharashtra, Karnataka, Punjab, Haryana and Rajasthan.
Maximum area under sweet oranges is in Andhra Pradesh followed by Maharashtra and
Karnataka. Well marked belts of sweet orange cultivation in the country are Abohar,
Fazilka, Ferozepur, Faridkot and Hoshiarpur in Punjab; Hisar in Haryana; Ganganagar
district in Rajasthan; Marathwada region of Central Maharashtra, Ahmednagar, Pune and
Nasik of Western Maharashtra and Anantapur, Kodur, Cuddapah Nelgonda, Chittor
districts of Andhra Pradesh.
Climate and soil
The production of sweet orange is largely favoured by dry, semi-arid to subtropical
conditions. However, plants grow well under sub-tropical climate and can even withstand
occasional light frosts. However, good results are not sure under cooler climates. Several
hours of exposure to a temperature of –3°C will cause severe injury to plants. On the
other hand, very high temperature are also detrimental. The average temperature for
growth is about 16–20°C. Hence, it can tolerate well maximum temperature of 32°–40°C
and minimum of 17°–27°C as it exists in most of the sweet orange growing belts of the
country. Being evergreen citrus require good amount of water and as least well
distributed annual rainfall of 500–775mm is necessary. When rainfall is unevenly
distributed over the year, additional irrigation will often be necessary. Under warmer
conditions, the colour development is poor, however, excellent deep orange colour of the
skin develops when grown under subtropical conditions. Quality is very good under dry
semi-arid conditions, while under humid conditions fruits turn insipid.
Sweet Orange can be grown on a wide range of soil. These will grown in almost any soil
if it is sufficiently aerated and deep allowing the roots to penetrate to desired depth. In
India, sweet orange is being cultivated on a wide range of soils e.g., alluvial, sandy loam
to loam, red sand soils to black clayey soils. In Andhra Pradesh, it is grown on red soil
with loamy sub-soils, red sandy soils and black clayey soils. The sweet orange growing
areas of Maharashtra have black soils. Thus, a well drained sandy loam to clay loam is
preferred by sweet oranges.
Varieties
Many varieties of sweet orange have been introduced into India but only a few prolific
ones having good quality could be established on commercial scale. Currently, exotic
varieties like Jaffa, Hamlin and Pineapple are performing well in Punjab, Haryana and
Rajasthan. Jaffa is a famous mid-season sweet orange while Hamlin is an early-season
variety. Pineapple is another mid-season variety. Another late season variety Valencia
has also shown good adaptability.
However, main varieties of sweet orange in India being cultivated on commercial scale
are Blood Red, Mosambi and Satgudi. Blood Red is the most important variety in
Haryana, Punjab and Rajasthan. and Mosambi is most popular in Maharashtra. Satgudi is
extensively grown in Andhra Pradesh.
Propagation and rootstock
The optimum performance of a variety depends on the proper selection of rootstock for a
given set of growing condition. Rootstocks are known to influence the overall
performance of a scion including quality. They are also helpful in countering particular
scion varieties, to various abiotic and biotic stresses including adaptability to various
types of soils. Hence, the selection of a rootstock for the adaptability to various agroclimatic conditions and suitability for a particular scion is a must.
In Punjab, Jatti Khatha and Karna Khatta for Blood red and other sweet orange varieties
are the most commonly used rootstocks. For Mosambi scion, Rangpur lime is the best
rootstock in Maharashtra. In Andhra Pradesh, commercially used rootstock, rough lemon
for Satgudi scion is being replaced now by Rangpur lime, which is highly tolerant to
drought and also have high productivity and comparable fruit quality.
Budding, i.e. with ‘T’ budding and Potch budding or Shield budding are the most
commonly used propagation methods for sweet oranges. When the rootstock plants of the
selected rootstock are one year old or come to a buddable stage, the bud of a desired
scion variety is budded at a height of about 25–30cm from the ground level. To ensure
good budding success, the budding is done during the months (January–March or
September–October) of active growth or when there is good sap flow in the plants. Thus,
budded plant should be immediately irrigated. Bud wood of the scion must be taken from
virus free indexed plants so that healthy, productive and true-to-the-type are produced.
Cultivation
Planting
Planting is generally done during monsoon in north-western and western parts of the
country, i.e. Punjab, Haryana, Rajasthan and Maharashtra, while in southern India, it is
done at the onset of rainy season.
Land should be ploughed in a cross manner to soften the upper surface. The pits of 60cm
× 60cm × 60cm size should be dug. They are filled with 15–20kg farmyard manure in
south and north India, while in western Maharashtra, the pits should be filled up first with
clay soil, murram, soil + farmyard manure mixture apart from 10% BHC powder and
micronutrients @ 25g each of Zn, Fe, Mn and Cu if initial fertility level is low.
A planting distance of 6m from plant to plant and 6m from row to row is generally
followed in square system of planting. However, planting distance as well as planting
density depends upon the cultivar, rootstock used and agroclimatic conditions. In general,
a density of 250–300 plants/ha in Punjab and Haryana is ideal for sweet orange cultivars
budded on Jatti Khatti rootstock. The optimum planting density for Satgudi Seedling
oranges is 170–200 plants/ha when budded on Sathgudi stock itself. In Maharashtra,
plants of Mosambi variety budded on Rangpur lime are planted at a distance of 6m × 6m,
accommodating 270 plants/ha.
Training and pruning
The trees are trained to a single system and any shoot emerging from the portion below
the bud union should be nipped off regularly. The first year growth beyond height of 0.7–
1m should be punched off to develop side shoot. Only 4–6 well having wide angle with
the main trunk, all around should be allowed to grow up to 3–4m. Thereafter no training
is required. Training of plants should be completed in first 3 years so that plants attain a
mechanically strong canopy. The pruning in pre-bearing trees may be done at any time
avoiding the peak winter.
Pruning of bearing trees though differs with variety. It consists of removal of dead,
diseased, criss-cross and weak branches. Removal of water sprouts and suckers from each
rootstocks below the bud union is also essential and should be attended to regularly
alongwith thinning of the shoots for better penetration of sunlight and aerations. The cut
ends after pruning should be treated with Bordeaux paste to avoid fungal infection. The
best time for pruning in bearing trees is after the harvesting during late winter or early
spring. After each pruning, spraying of Bavistin (1ml/litre water) is beneficial to avoid
any secondary infection.
Manuring and fertilization
Fertilizer requirement of the plants is influenced by various factors like age of the plant,
root-stock used soil and climate alongwith the crop load in bearing trees. No uniform
fertilizer recommendation can be made for all sweet orange cultivars in different agroclimatic regions. The fertilizer schedule commonly adopted in different parts of the
country is given in Tables 1 and Table 2.
The fertilizers should be applied in a ring from below the canopy of the trees depending
on age. For a mature tree furtilizer is applied in a 30–40cm wide ring made at a radial
distance of 100–200cm from the trunk as maximum feeder roots are located in the zinc
below the tree canopy.
Though the requirement of major elements is by and large met by supplementing N, P, K
fertilizers, farmers usually forget to apply micronutrients, the most essential part of citrus
nutrition. Very often the diagonistic symptoms of nutrients are very fieble to get usliced.
Further, deficiency symptoms of Mn, Fe and Zn resemble very closely, making it difficult
to judge which nutrient is really deficient. It is also well known that the deficiency of zinc
alongwith N and to same extent P is a major nutritional problem of sweet orange in north
India, western Maharashtra and south India. Deficiency of Fe and Mn is also observed in
some areas. Hence a micronutrients mixture should be given when the leaves have fully
expanded after a new flush growth. A combined spray of different micronutrient is
presented in Table 3.
Aftercare
Most of the sweet orange cultivars are planted 6–8m apart, leaving much area unutilized.
The interspaces can profitably be utilized for growing some short-duration crops. The
additional crop not only provides additional income to the orchardists, but also helps to
check weed growth, conserve soil moisture and prevents soil erosion. During the initial
years of the orchard development, and vegetables as soybean and cotton are successfully
cultivated as intercrops. Peas, turnips and cabbage rabi crop and bottlegourd, bittergourd
and lady’s finger in kharif as intercrops as intercrops are grown as water crops in north
India.
Weed control
In order to eliminate competition for nutrition by weeds in sweet orange orchard, control
of weed is very essential. Apart from interculture operations, that check weed growth,
chemical weed control is also necessary during certain period of the year to avoid
disturbances to feeding roots. Both pre-emergent and post-emergent sprays for weed
control are necessary.
Application of Diuron as a pre-emergence weedicide spray @ 3 kg/ha twice at 120 days
interval is quite effective to control weeds up to 280 days.
For post-emergent control, use of 2, 4-D (Fornoxone) @ 5 kg/ha in 500 litre of water
followed by a composite spray of 2.5 litres Paraquat (Gromaxone) plus 1.25 kg 2, 4-D
(Fernoxone) in 500 litres of wate/ha 10–20 after the first spray is quite effective in
controlling weeds. The conposite spray of Paraquat and 2, 4-D may be repeated twice at
30 days intervals if needed. The controls/reduces the weed growth for about 4–5 months.
Irrigation
Sweet oranges require more water because sap circulation never entirely ceases and
transpiration takes place throughout the year. Being are evergreen plant, sweet orange
requires good amount of water and water deficiency moisture stress at critical periods
such as front development checks the growth reduces fruit size and quality. Thus
moisture stress during the period of growth, flowering and fruit development should
always be avoided.
The frequency of irrigation is influenced by soil, climate, variety and age of plants. In
northern India and western Maharashtra, water is applied at every 6–8 days intervals from
March to June and every 10–12 days intervals during November–February. Sweet orange
being is susceptible to waterlogging and Phytophthera rot stagnation of water in the
orchard and around the tree trunk is to be avoided.
In young plants up to the age of 8-year, the irrigation should be given through basin
system of irrigation. In grown up and old orchards, food system of irrigation may be
adopted avoiding water content with tree trunks. In western Maharashtra, drip irrigation
system is gaining popularity, ring system of irrigation is adopted for this. Double
ring system or bed irrigation is best in reducing the water contact with the tree trunk thus
avoiding fungal of infection.
A grown up sweet orange tree needs about 25–20 irrigations in a year, amounting about
1,325mm of water. Its plants have highest demand of water during fruit development. It
is advisable to irrigate the orchard after the fruits have attained pea size.
Harvesting and Postharvest Management
Sweet oranges mature in 9–12 months. Being to a non-climacteric fruit, there is no
improvement in colour, taste and flavour after harvesting. Therefore, fruits should be
harvested when they are fully ripe and attain proper size, attractive colour and acceptable
sugar: acid blend.
Sweet oranges can be allowed to remain on their trees on reaching maturity for several
weeks without deterioration, except in area and varieties where the incidence of fruitsucking moth (south India) and granulation (north India) are problems. In such areas, an
early picking is advised.
Main harvesting season in north India is from December to February, while in south India
it is October–March. In Andhra Pradesh, Sathgudi oranges are harvested during
November–March. In central and western India, November–January for ambe bahar and
March–May for mrig bahar are time for harvesting. Fruits should preferably be harvested
by clipping with secateurs.
Sweet oranges are tight skinned fruits possessing comparatively better shelf-life than
loose skinned mandarins. Ripening is a terminal period of maturation, when fruits
develop complete blend of flavour, texture and aroma contributing to optimum eating
quality. The period of ripening and TSS : acid ratio at which sweet oranges should be
harvested are given in Table 4.
Washing, drying, sorting, grading and wrapping in tissue paper is usually adopted for
postharvest handling and packaging. Latest technology of packing fruits in corrugated
boxes instead of hardwood boxes helps in lengthening the shelf-life of fruits. Nowadays,
shrink wrapping of fruits in desired number of packs is also getting popular. Perforated
polythene packing is also gaining popularity.
Dipping fruits or spraying fruits with 5% fungicidal emulsion and then dipping them in
500 ppm Benlate or 0.1% Carbendazin (Bavistin) solution helps reduce spoilage and keep
them in good condition at room temperature for 20 days after harvesting.
Sweet orange variety Malta can be effectively stored at 4.4°c in cold storage for 2–3
months, while that of Sathgudi at 2°c over 4 months. Mosambi obtained in western
Maharashtra can be stored at temperature of 5°c and 85–90% relative humidity for 3
months.
Sitaphal
Edible
fruits of genus Annona are collectively known as annonaceous fruits.
Of the 40 genera of the Annonacae family, genus Annona has 120 species, 6 of them
having pomological significance. Annona fruits are syncarpia formed by fusion of pistil
and receptacle into a large fleshy aggregate fruit. Annonaceous fruits have morphological
affinity for each other but each type is unique in its taste, flavour, pulp colour and texture.
The edible annonas have important features which are given in Table 1.
Among annonaceous fruits, custard-apple is the most favourite in India. Its plants come
up unattended in parts of Andhra Pradesh, Assam, Bihar, Karnataka, Maharashtra,
Madhya Pradesh, Orissa, Rajasthan and Tamil Nadu as a scrub or hedge plant. Of late,
custard apple has gained commercial significance and exclusive orchards are emerging in
Andhra Pradesh and Maharashtra.
Other annonas are cultivated on a limited scale. Bullock’s heart is more commonly found
in south India than in north India. It is usually associated with gardens and compounds
and not commercial orchards. Cherimoya is mostly restricted to Assam and hills of south
India. Atemoya and sour sop are cultivated in some gardens as miscellaneous fruits.
Atemoya, cherimoya and ilama also provide excellent opportunities for a large-scale
exploitation in India.
Climate and soil
Most annonaceous fruits are acclimatized to tropical climate. Although custard-apple
withstands heat and drought conditions, high atmospheric humidity is necessary during
flowering to improve fruit set. But continuous rains during fruit set are not desirable. An
annual rainfall of 60–80cm is optimum. It cannot stand frost or a long cold period.
Bullock’s heart grows well in humid regions of south India and cannot withstand severe
summer. It tolerates frost to some extent. Cherimoya prefers subtropical climate, but it
can flourish on higher elevations (2,000m) in tropics. While climatic requirements for
atemoya are quite similar to those of custard-apple. Sour-sop in contrast, is a fruit of the
humid tropics.
Annonas thrive naturally in rocky terrain with shallow, gravelly, well-drained soils.
However, they may grow well in arable, red, sandy shallow soils slightly acidic in
reaction. Heavy soils are not suitable, especially in waterlogged areas. In Andhra Pradesh,
annonas come up on chalka—red sandy or gravelly soils. They can grow well even on
calcareous soils containing lime as high as 50%.
Varieties
Custard-apple seedlings are found growing wild in India. Since custard-apple is a crosspollinated crop, wide variation in forms and sizes of fruit as well as colour of the pulp are
available. This natural variability available within the species is often exploited to
identify superior gentoypes which are usually named after the place of collection or
selection and fruit colour. Depending on external fruit colour, custard-apple is
distinguished into green, red and yellow. But green ones are by far more common and
popular than the other types. Balanagar, Barbados Seedling, British Guinea,
Kakarlapahad, Local Sitaphal, Mahaboobnagar, Saharanpur Local and Washington are
some of the varieties with green skin. Most of these varieties are not easily identifiable.
Some of the traits that distinguish them are fruit shape and size, form of areoles and
number of seeds/fruit. But in fruits of a given tree, these attributes vary considerably as
they are largely influenced by pollination and the environment. Thus, the varietal or
genetic differences get masked confusing the varietal identification. Moreover, varietyspecific pulp qualities are not clearly explained. However, some varieties can be
recognized by the plant habit and foliage attributes. Two natural hybrids (mostly between
custard-apple and cherimoya), Israeli Selection and Israeli Hybrid, have been introduced.
Fruits of both are less seeded. A hybrid Arka Sahan has slow ripening (6–7 days), better
shelf-life (2–3 days), less number of seeds (10/100g fruit weight) and high brix (31°). On
an average its fruits weigh 210g each. A 6-year-old plant yields 17kg fruits. Other
annonas are usually propagated by seeds. There are no well-recognized varieties used for
cultivation.
Propagation and rootstock
Most of the annonas are traditionally propagated by seeds. The seed viability lasts for 3–4
years. However, fresh seeds germinate better. Hard seed-coat can be softened either by
soaking the seeds in water for 2–3 days or keeping them under running water for 50–70hr.
Treating seeds with GA3 at 500ppm assists germination. Seeds are sown 2cm deep either
in nursery beds or in pots under partial shade. Regular watering is necessary to maintain
good soil moisture. Seeds are slow to germinate and take 3 weeks. Nevertheless it may
extend to as long as 8–10 weeks. When seedlings are 10–12cm tall, they are transferred
to pots or plastic bags containing sand and peat or equal parts of garden soil, sand and
decomposed farmyard manure. The 30cm tall seedlings become ready for transplanting.
Seed originated plants are not true-to-type, lack precocity and vigour, whereas grafting or
budding helps largely to overcome these drawbacks. A. squamosa, A. reticulata, A.
cherimola and A. atemoya are grafted or budded on their own species and each other. A.
muricata can be grafted on A. reticulata and A. glabra. However, A. reticulata which
promotes vigour and shows good graft congeniality is commonly employed as a rootstock
for most of the annonas.
Generally, 18-month-old or 30cm tall plants having pencil thickness are selected for
grafting. Scion of well-matured wood from which the leaves have dropped at the end of
the dormant phase is used to graft either by veneer or cleft technique. Shield or Tbudding carried out in spring is also equally effective. Patch and chip budding are other
methods. Large buds, about 4cm in length, collected from 1-year-old wood after the leaf
drop give good success. The graft should be uncovered once it has taken in order to avoid
rots. Since propagation by cuttings and air-layers gives poor results, they are not widely
practised. Commercial production of plants through tissue culture is not yet successful.
However, multiple shoot production from leaf explants of seedlings and root initiation
from shoots are successful.
Cultivation
Planting
Pits of 60cm × 60cm × 60cm size are dug and left open to sun for a week. They are filled
with top soil mixed with 25–30kg of well-decomposed farmyard manure. Custard-apple
should be transplanted 5m × 5m apart (400 plants/ha). However, setting plants closer may
be preferred. Plants spaced at 4m × 4m (625 plants/ha) not only accommodates over 50%
additional plants/unit area but promotes better fruit set by improving pollination, a
problem in annonas. Due to larger canopy, atemoya and bullock’s heart require a plantto-plant spacing of 6m × 6m and cherimoya and sour-sop 8m × 8m spacing.
Planting should be carried out preferably in spring so that plants establish roots in
summer, start growing as the weather warms up and put up vigorous growth during rains.
However, if adequate irrigation facilities are lacking, monsoon is the optimum time for
planting. To keep the graft-joint well above the ground is a must. As soon as a young tree
is planted, it should be irrigated till it establishes.
Pruning
Annonas require little pruning. It is essential to develop a good crown and better yields
over a long period of time. Without pruning, the plants become bushy and their bearing
efficiency comes down. Hence, timely removal of misplaced limbs is necessary to build a
strong framework. Selective and mild pruning of deadwood and very old branches should
be carried out to avoid congestion and encourage well-spaced branching. Severe pruning
is detrimental for the plant growth. Yellowing of leaves starts as the harvesting season of
fruits ends. The leaves begin to drop with the onset of winter and fresh growth occurs in
spring. Flowering occurs singly or rarely in small clusters mostly on current season’s
growth and occasionally on old wood. Training to a single stem is the only option when
rootstock is employed.
Manuring and fertilization
Applying manures and fertilizers to custard-apple is not common but its plants respond
very well to fertilization, increasing vigour, yield and fruit quality. Fertilizer application
checks decline and extends longevity of trees. To specify the precise dose common to all
soils is difficult, but general recommendations are given in Table 2. The area below the
crown of trees should be cleaned of weeds. Then apply fertilizers in the basin under the
tree but not within 30cm of the trunk. Subsequently it is desirable to irrigate the trees and
incorporate the fertilizers. Fertilizer application should coincide with rapid vegetative
growth and fruit development. As fruits are borne on new as well as old wood,
application of slightly higher dose of N is not harmful. There is a lack of information on
fertilizer application to other annonas species but they can be benefited by following the
doses recommended for custard-apple.
Aftercare
After planting, the young plants must be watered and supported by stakes to keep them
erect. To start with a 60cm × 60cm basin around the plant is adequate. Regular watering
during dry periods, occasional hand digging of the basins to check weeds, to keep the soil
loose, attending plant-protection measures, manuring, removing of sprouts on stock and
building up of a good framework are necessary cultural operations. The basins around the
plant should be enlarged as the plants grow bigger. They should be made little larger than
the spread of the plant.
In young orchards, a lot of land remains vacant between the rows for 4–5 years. Hence,
short-duration vegetables—tomato, onion, chilli, okra, brinjal, radish or cowpea,
greengram, horsegram, or any green manure crop—can be intercropped. These crops
should not be raised too near the tree, lest they compete with them for nutrients.
Irrigation
Most of the annonas produce a moderate crop even in the absence of irrigation. Irrigating
plants at least during flowering and fruit development is essential. Fruit quality is
superior in irrigated plants with more edible pulp/ segment. Plants receiving regular water
grow luxuriantly with each bearing. Pruning, fertilization and irrigation are quite essential
to get maximum yield.
In regions having limiting water, pitcher, trickle or drip irrigation systems help in
judicious use of water. Fruits are raised as rainfed in low rainfall areas land shaping to
divert rain water near the plantation may be taken up. Contour terraces, contour bunds
and micro-catchments also help in efficient water use. Even ploughing of the plantation
during rainy season helps better conservation of moisture. Custard-apple plants especially
in neglected areas are benefited from these operations.
Harvesting and Postharvest management
Custard-apple starts bearing fruits at the age of 4–5 years. It declines by about 15th year
depending upon the maintenance. Custard-apple produces single crop in a year during
August–October in south India and September–November in north India. On maturing,
fruits turn light green. The inter-areolar space widens, the fruits turn creamy-white.
Custard-apples are harvested manually when they are fully mature but still firm. If they
are left for a longer time on trees, they split open and are spoiled. About 4–5 pickings are
required. Occurrence of deformed fruits is due to carpels with unfertilized areoles failing
to grow. Fruit yield varies widely from tree-to-tree. Normally a 7-year-old tree produces
100–150 fruits, the total yield being 7 tonnes/ha.
Bullock’s heart and cherimoya are ready for harvesting during January–February and
December–January, yielding 50–75 fruits/plant. Since both have thick stalks, it is
necessary to harvest them with the stalks using secateurs. Atemoyas are somewhat early
(September–October) and are shy-bearer. Higher yield (50–60 fruits) may be obtained
with hand-pollination. Sour-sop, the largest annona, produces about 25 fruits/tree during
June–August in south India.
Annonas are climacteric fruits. Custard-apple takes about 3 days to ripen, while others 4–
7 days. Prior to ripening the pulp of matured custard-apple is not separated into segments
or flakes. It is only during conversion of starch to sugar this differentiation occurs. In ripe
fruits of bullock’s heart and cherimoya the pulp is more or less homogeneous mass of
closely cohering carpels which cannot be separated easily.
Ripe fruits of custard-apple and sour-sop are very fragile and with the slightest pressure,
the fruits easily get disintegrated into segments. Hence extra care is necessary while
handling. Ripe custard-apples can be stored for about 2 days, but other annonas can be
stored for 3–4 days. This may be partly due to the characteristic feature of the rind. In
bullock’s heart and cherimoya, the carpels are not associated with external areolar
divisions on the rind and the surface appears to be contiguous or almost fused unlike that
in custard-apple. Thus the fruits do not split easily along the deep furrows between the
interareolar spaces, the weakest portions of the rind.
Custard-apple, atemoya, bullock’s heart and cherimoya are normally used as fresh fruits.
Ripe fruits are popular among the poor. The unripe fruits of custard-apple are eaten in
Andhra Pradesh after baking or roasting. The raw fruits of sour-sop are commonly used
to prepare soup or vegetable.
The pulp of custard-apple mixed with milk is made into a delightful drink or ice-cream.
Development of a repulsive off-flavour on heating beyond 65°C and presence of gritty
cells are major constraints in processing custard-apple. But its juice is a potential
ingredient to prepare squash, syrup, nectar and a fermented alcoholic beverage. Jam, jelly,
conserves and tarts can also be prepared from the pulp of custard-apple. It is also possible
to can the pulp. The sweetish sour flesh of sour-sop is fibrous, juicy with pleasant aroma
and is amenable for preparation of ice-cream, sherbat and syrup.
Physiological disorders
With the end of harvesting season, the leaves of custard-apple turn yellow and with the
onset of winter, leaves fall down. New growth commences in spring after passing a
dormant phase in winter. But in certain neglected plants or those under severe moisture or
nutritional stress, the dormancy sets well in advance and some fruits turn brown, become
quite hard and without further growth remain on tree for months even in the following
season. Such fruits are referred to as ‘stone fruits’. This disorder can be corrected by
practising clean cultivation, manuring, timely irrigation and application of
superphosphate and bone-meal. If plants are well attended, they flower in time and their
fruits mature before the plants enter dormancy without stone formation. Sometimes, very
young fruits turn black, become hard and stop further development. This mummification
of fruits appears to be a natural thinning mechanism, especially during periods of drought.
Tree decline caused by water stagnation is another problem. Such trees shrivel and drying
of old branches takes place and they die suddenly. Stagnation of water during heavy rains
should be avoided.
Sapota
Sapota or sapodilla (Manilkara achras), popularly known as chiku, is an important fruit.
Native to tropical America especially from south Mexico or central America, this species
is mainly grown for its chickle, "the gutta parcha" extracted from its latex from stems. It
is used as a base material in chewing gum and in some other industrial uses. However, in
India it is cultivated for its delicious sweet fruits. The fruit is fleshy berry, variable in
shape, size and weight (75–150g). The skin is thin, rusty brown somewhat scurfy looking
like Irish potato, and the pulp soft, melting, crumbling with a sandy or granular texture
with 1–5 hard, black seeds. The fruit is a good source of digestible sugar (12–18%) and
an appreciable source of protein, fat, fibre and minerals, Ca, P and Fe. It has become
most popular fruit crop in Gujarat, Maharashtra, Karnataka, Tamil Nadu, Andhra Pradesh
and Kerala.
Climate and soil
Sapota, a crop of tropical region, needs warm (10°–38°C) and humid (70% relative
humidity) climate where it flowers and fruits throughout the year. However, if taken to
subtropics or higher elevation like in Punjab and Haryana, it gives only one crop from
summer flowering in April and May. Under moisture-stress also, it produces one crop
only.
Varieties
There are about 41 varieties spread all over the country. However, commercially sapota
industry is based on a few varieties and in some areas it is only monoculture like Kalipatti
in Gujarat and Maharashtra. Distribution of cultivars according to region is given in
Table 1.
Propagation and Rootstock
Sapota is propagated through seed, which has been the basis of its variability in India.
But inarching using rayan as rootstock, air-layering and softwood cuttings, using IBA
(2,000ppm) treatment are successful methods of propagation. However, plants raised
through air-layering or cuttings establish poorly and are vulnerable to wind damage.
However in west-coast, air-layering is common and such plants perform better in shallow
soils. For air-layering, 1–2 years old 45–60cm long juvenile matures shoots of pencil
thickness with plenty of healthy dark green leaves are selected. On the base of such
shoots a ring of bark (2.5–3cm wide) is removed on which IBA + NAA (10,000ppm)
each in lanolin paste is applied, covered with rooting media like sphagnum moss,
vermiculite or garden soil and wrapped with plastic. In 3 months, roots emerge, then
layers are slowly separated and establish in nursery. They are planted in the next season.
Sapota on rayan is the best in respect of plant vigour, productivity and longevity.
Propagation of sapota by inarching using rayan as rootstock is the most accepted method
of its commercial cultivation. Two years old potted rayan plants with pencil thickness are
utilized and grafting is done in December–January. The plants are ready for separation in
June–July of following year. This method is tedious, cumbersome and time-consuming.
Softwood grating using rayan as rootstock gives 93% success in-situ. It is an
economically viable, faster, efficient and best technique. July–August is ideal time for it.
Since detached scion is used in this method, it is possible to store scion sticks in banana
sheath to help exchange of plant material.
Cultivation
Planting
Since sapota is a crop of warm and humid tropics, it can be planted in any season
provided irrigation facilities are available. But it is beneficial to plant the grafts in
beginning of the rainy season. In areas having heavy rainfall, it can be planted in
September. In light soils, pits of 60cm × 60cm × 60cm size, whereas in heavy and
gravely soils pits of 100cm × 100cm × 100cm size are made in April–May and exposed
to sun for 15 days. Top 30cm soil is mixed with equal quantity of well-rotten compost or
farmyard manure, 3kg superphosphate and 1.5kg muriate of potash are used for pit filling.
To begin with all sides and bottom of the pit are dusted with 5% BHC dust and pits
mixture is added to fill the pit and remaining vacant space is filled with remaining soil to
a height of 15cm above soil surface. Such pits are left to monsoon rains for settling and
then planting is done at appropriate time. At the time of planting, a small hole sufficient
to accommodate the ball of soil and roots of grafts is made in the centre of the pit and
planted with scion in the direction of heavy wind to avoid damage to joint. After planting,
soil around the plant is gently and firmly pressed and stakes are provided to avoid wind
damage. Planting should preferably be done in the evening to avoid sun heat. The plants
are then lightly watered. Young plants should also be protected against sun scold by
providing dry grass thatch on top and three sides excepting the south-east for sunlight.
Such well-cared plants establish fast.
Since sapota tree makes uniform all-round growth, square system of planting is
recommended. However, in land with 5–15% slope, contour planting is recommended.
Depending on growth habit, sapota orchards are planted at 10m × 10m but being slower
in growth, it takes longer period to occupy allotted space. Therefore, high-density
plantations having 5m × 5m spacing up to the age of 13 years are very remunerative.
Thereafter yields begin to decline.
Training and pruning
A seedling tree grows excellently giving a shape of an umbrella. However, plants raised
through inarching require training for appropriate shape and framework development. No
definite system of training has been developed for sapota. Most trees are trained in
central leader system.
Sapota being an evergreen tree requires no regular pruning but regulation of vegetative
growth to improve productivity and quality of fruits is necessary. At times thinning of
branches is affected in old plantation. Pruning in sapota is confined to open the tree to
light, and removal of dead and diseased branches.
Manuring and fertilization
Owing to evergreen nature of the plant, any inadequacy in its nutrition leads to suboptimal yield. Deficiency of N leads to yellowing of leaves from margin to mid-rib. The
P-deficient plants have purplish flecks on lamina with rusty pigmentation all over and
inadequacy of K is marked by development of chlorotic symptoms along leaf margins
which become dark grey in advanced stage. Zinc deficiency is marked by small and erect
leaves, short internodes and defoliation of terminals, whereas in calcareous soils Fe
deficiency causes general yellowing of leaves with premature shedding.
A dose of 50kg farmyard manure, 1,000g N, 500g P2O5 and 500g K2O/tree/year is
optimum. This quantity can be regulated on the basis of age of tree and status of nutrients
in soil especially of P and K. Under rainfed conditions, dose of N should be raised to
1.5kg/tree. Castor cake is beneficial for high-quality fruits. The nutrient doses prevalent
in the country are given in Table 2.
Under rainfed condition, fertilizers should be applied before the onset of monsoon.
However, under irrigated conditions it should be applied in 2 splits. Total quantity of
organic manure and half of chemical fertilizers should be applied at the beginning of
monsoon and remaining half in the post-monsoon period (September–October). Since
90% of active roots are distributed within drip up to a depth of 30cm, nutrients should be
applied under tree canopy and mixed thoroughly in soil up to a depth of 15cm. In Zn and
Fe deficiency, the requirement should be met through application of organic manures and
spraying of ZnSO4 and FeSO4 (0.5%).
Aftercare
Depending on growth habit of sapota tree a planting distance of 10m × 10m is ideal.
Being a slow-grower, it takes longer to occupy allotted space. Therefore, intercropping is
imperative. Intercropping banana, papaya, pineapple and cocoa; French bean, tomato,
brinjal, cabbage, cauliflower and cucurbits is recommended depending on climate and
water resources. In established orchards, pre-monsoon and post-monsoon intercultivation
is recommended for better aeration and effective weed control. In young orchards, weed
hazard is common. Use of 2kg Bromacil + 2kg Diuron/ha as pre-emergence spray is
effective for a period of 10–12 months. Mixed plantation with mango and guava should
be avoided to reduce the problem of fruitfly.
Irrigation
Habit of tree and its vegetative growth demand continuous supply of water. But sapota is
grown both under irrigated and non-irrigated conditions. Sapota requires irrigation at 30
days interval in winter and 15 days in summer. Adoption of drip irrigation system is also
beneficial, saving 40% water with 70–75% higher net income. This system should be laid
out with 2 drippers spaced 50cm from tree during initial 2 years and 4 drippers at 1m
from tree until 5 years of age. With dripper discharge rate of 4litres/hr, the system should
be operated for 4 hr during winter and 7 hr during summer on alternate days. Under short
supply of water, timing could be 3hr and 30minutes in winter and 5hr and 40minutes in
summer.
Harvesting and Postharvest management
Sapota takes about 7–10½ months from anthesis to maturity of fruits depending on
variety and climate. Fruits follow double sigmoid pattern of growth. Properly developed
fruits have high TSS and sugar, and reduced acidity, astringency, latex and vitamin C.
Maturity is decided on the basis of ease with which brown scruff gets off the fruit surface
and development of yellowish tinge intermixed with corky-brown colour on the surface
of the fruit. At this stage, practically no green tissue and milky latex are seen on fruits
when scratched with nails. The fruits are hand picked or harvested with special harvester
which has a round ring with a net bag fixed onto a long bamboo. Depending on
management level, 15–20 tonnes fruits are harvested from a hectare.
Since sapota is a climacteric fruit, it has to be ripen artificially. Fruits are highly
perishable and they undergo rapid ripening changes within 5–7 days during which the
fruits become soft, sweet and develop excellent aroma with decline in tannins, latex
sapotin, aldehydes and acidity. These changes are associated with increase in production
of ethylene, rate of respiration, catalase, peroxidase and PME activities. These changes
can be regulated through chemicals, temperature and storage gas composition.
Harvested fruits should be cleaned of latex and scurf by washing in clean water to make
them look attractive. Such fruits should be graded into big, medium and small sizes.
Fruits should be tightly packed in cardboard boxes of 10kg capacity with rice straw as
padding material and with ethylene absorbents and transported quickly to wholesale
markets. For extending shelf-life and to avoid storage rots, fruits can be dipped in GA
300ppm + Bavistin 1,000ppm solution at prepacking stage. For uniform and rapid
ripening Ethephon (1,000ppm) can be utilized at 20°–25°C. Modified storage with 5–
10% (c/c) CO2 can be employed for long storage (21–25 days). Refrigerated vans (12–
13°C) should be utilized for long distance and export markets.
Physiological disorders
Wilt or die-back is common where sapota cultivation is being extended to traditionally
rice-growing regions. Due to anaerobic conditions in monsoon and post-monsoon season
in such areas wilt is of common appearance aggravated by Fusarium spp. This can be
controlled by effectuve drainage facility before planting.
The shape of fruit is related with number of seeds in it which depend on conditions for
pollination at anthesis. High temperature and rainfall during flowering cause oblongation
of fruits. Therefore, cultivation of sapota in areas with extreme summer temperature
should be avoided.
Sometimes fruits do not develop into their normal shape but develop a depression or
furrow towards the calix-end. This symptom usually appears immediately after heavy
rainfall and is aggravated by high intensity of irrigation. Therefore over-irrigation should
be avoided.
The fruits exposed to intense sunlight do not ripen uniformly, developing corkiness
during winter. This is probably due to killing of hydrolysing enzymes by alternating
moisture accumulation and heating of fruit surface in winter. Thus its trees need to grow
vigorously.