Introduction
- Both soil and climate of a ecosystem are the important factors which
determine about success or failure of mango crop.
- Therefore one should give atmost importance to these two factors
before establishing a mango orchard.
- Presently mango is being grown in varied types of soil as well as
in different types of climatic conditions across the country.
- While planning a mango orchard atmost importance should be given to
take soil sample and its analysis for pH. nutrient status, EC, water
soluble salt content etc.
- Similarly with respect to climatic conditions temperature, rainfall,
wind, hailstorms and altitude of the given place should be considered
especially in the selection of a variety.
- In this chapter the details of all these factors have been discussed
at length.
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Soils
- Mango grows well on all types of soil provided they are deep and well
drained.
- Red loamy soils are quite ideal.
- Alkaline, ill drained and soils with rocky substratum are not suitable
for successful cultivation of mango crop.
- In India, mango is grown on lateritic, alluvial, kankar and
other types of soil.
- However, rich, medium and well drained soils give better results.
- Very poor, stony and soils with hard substratum should be avoided.
- The vigour and cropping behavior of a mango tree are affected by the
soil type.
- In our country the best mango gardens are situated on the deep fertile
alluvial soils of the Indo-Gangetic plain.
- On shallow soils of hill slopes, mango trees grow to a large size
but the yields are not satisfactory.
- On the laterite soils of the west coast and of Bidar (Karnataka) the
trees are smaller and sandy loams of Telangana region
India, produced trees of medium height.
- The red soils of Dharwad (Karnataka) and red laterites of Belgaum
and Ratnagiri (Maharashtra) and Goa Island (India) are the best soils
for mango.
- Best quality fruits are produced on soils containing 5 to 10 per cent
lime and sufficient quantities of peroxide of iron.
- Under such conditions fruits develop bright reddish tinge.
- The deep black cotton soils are generally considered not suitable
for mango cultivation, since soils are generally avoided for planting
mango plants.
- Such soils need to be reclaimed by leaching out of salts using good
quality water, replacing the harmful sodium from the soil with calcium
or by establishing effective drainage course to avoid salt build up.
- However, these are costly and the expenditure is likely to recur
as a continuous threat of salinity faced year after year.
- The mango growing soils should preferably have a very low total water
soluble salt content of 0.04 to 0.05 per cent.
- Fruit crops are most sensitive than cereals and millets.
- Mango is rated as moderately tolerant to salts with 4-6 dsm-1.
- The fertility of soil is dependent on its physical, physico-chemical
and chemical characteristics.
Physical Characteristics
- Some of the important factors included under physical characteristics
of soil are the slope or contour of the land, soil type, depth of soil
and water table.
Slope or contour of the land
- This is an important factor for successful growth and development
of mango crop.
- The land should be slightly elevated with little slope towards the
drain.
- The drained and basin shaped areas should be avoided because such
areas collect more rain water and become water logged.
- Such situations lead to poor aeration of roots and the roots may turn
black and rot, ultimately die.
- It is a common experience to see that, those trees that are subjected
to floods or low lying with poor drainage generally die quickly.
- This kind of damage has been noticed in the waterlogged areas of Telangana
(India). Elevated locations are more ideal for mango
cultivation.
- Soils with too much of slope are prone to erosion and too much of
drainage and such soils also get moisture depletion
quickly and require frequent irrigations.
Soil profile
- The fertile soil is the one that is present in the top 15 cm level.
- It is the cultivated portion of the land.
- Normally the soil profile is studied from top to a depth of 1.8 m
or more.
- It is a pre-requisite for assessing the suitability of the soil of
any crop.
- The depth, texture, structure and others are also considered.
Depth of the soil
- Mango has very deep and strong root system thus soils for mango should
be quite deep for easy penetration and spread of the root system.
- Soils with a depth of 1.2 m or more are ideal for mango crop. More
the depth of soil, better is the suitability.
- Hard soils, soils poor in depth or soils having hard pan in sub-soil
should be avoided.
- The deep and well drained soils with no impervious layers, allow good
depth and distribution of root system producing trees of standard size,
heavy yields and long life.
Texture
- In India some of the best mango orchards are located
in the Gangetic plains of northern India and also on
the banks of great rivers of peninsular India.
- The soils in these regions are highly fertile and silty loams or alluvial
loams.
- Sandy soils are poor in organic matter content and other plant nutrients,
as such they need to be supplied by heavy manuring.
- Such soils do not provide good anchorage to root system.
- Sandy or gravelly soils have poor water holding capacity.
- While growing mango in such soils, texture of soil should be improved
by periodical application of organic manures like farm yard manure or
compost.
- The most desirable soil for mango is one of medium texture, deep and
well-drained.
Structure
- It refers to arrangement of soil particles.
- The structure of the soil in different horizons should be open, granular
and compact structure should be avoided.
- The sub-soil should be friable.
- They should not be impenetrable pans such as clay, Kankar and
rocky.
- The presence of a substratum of loose gravel or murum helps
in providing good drainage.
Root penetration
- It is also a measure of soil aeration.
- The top 1 m soil should atleast permit the penetration of most roots
of plants in plenty.
- Poor drainage is reflected by the poor growth, sickly appearance or
death of plants.
- Mango being a hardy crop, its roots penetrate easily into hard soils
like laterite soil and the plant grows luxuriantly.
- Many such mango gardens grown on lateric soil can be seen in west
coast of India and more particularly in Konkan region of Maharashtra,
Goa and coastal Karnataka.
Water table
- A constant water table is more preferred for good growth and development
of mango crop.
- During any part of the year water table should remain constant and
should never fluctuate.
- For mango the water table should always be at a depth of 1.80 to 2.40
m.
- If water table is too high then feeder roots will be submerged with
water for a long time leading to chloratic patches on leaves.
- Though the plant may not die but remain unhealthy and growth of the
plant is adversely affected.
Chemical Characteristics
- The chemical characteristics include nutrient status, soil reaction
and salt content of soil.
Nutrient status
- Classification of soils with regard to mango has been done only to
certain extent.
- Nutrient uptake by mango differs with the variety, age of the plant,
soil type and management.
- In general, a crop producing 15 t/ha removes 100 kg N, 25 kg P2O5
and 100 kg K2O.
- A definite correlation exists between nitrogen, phosphorus, potassium
and calcium status of soils and yield of mango.
- This has been revealed by a preliminary survey of soils conducted
in areas of best mango gardens in Bihar.
- In Tamil Nadu, it was noticed that presence of peroxide of iron in
the soil increased the vigour of trees and sweetness of fruits.
- Most of the mango-growing soils in India have a low soluble salt content,
ranging from 0.04 to 0.05 per cent, whereas the total P2O5
varies from 0.06 to 0.0605 per cent, and available K2O from
0.008 to 0.0087 per cent.
Soil reaction
- The soil reaction or the soil pH affects the growth of mango trees
to a certain extent.
- Highly calcarious soils having large quantities of lime nodules are
considered poor for mango cultivation.
- Being highly alkaline, young plants are subjected to burning.
- Such soils are rich in sodium and become impenetrable to water.
- The presence of small amounts of kankar in neutral or slightly
alkaline soils upto pH of 7.5 may not harm the tree.
- A range of 5.5 to 7.5 is ideal for mango growing.
- The soils should preferably have a very low total water soluble salt
content (0.04 to 0.05%).
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Climate
- Mango is grown in both tropical and sub-tropical conditions.
- It can tolerate a wide range of climatic conditions.
- For growing mango on a commercial and profitable scale the temperature
and rainfall have to be with in a clearly defined range.
- In addition to altitude, temperature, rainfall and the wind velocity
also influence growth and production of mango. Mango thrives well under
humid and dry conditions.
- It requires good rainfall during its growing season i.e. June to October
and rainless, dry weather from November onwards.
- Rainy or cloudy weather during flowering favours the incidence of
powdery mildew disease and leafhoppers.
Altitude
- The climate of India is more suitable for successful growth and development
of mango crop.
- As a result one can see large number of mango gardens in almost all
parts of the country.
- Altitude of a place is one of the important features of the climate
which determines good growth of the crop.
- The plant grows luxuriantly and yields well from sea level to 1000
m above mean sea level.
- However, for commercial cultivation of mango crop 600 m altitude
is ideal.
- As the altitude of the place increases over and above 1000 m from
MSL the growth and productivity of the crop are poor.
- The altitude has a definite role on the time of mango flowering.
- It has been observed that an increase in every 12 m altitude, flowering
is retarded by four days.
- Similarly for each degree latitude, south or north of the tropics,
flowering is delayed by four days.
Temperature
- Climatic conditions particularly temperature, also govern the flowering
time and ripening time of fruits.
- Mango starts flowering early in Bihar, Bengal and eastern Uttar Pradesh
due to onset of high temperature early in the season.
- Fruit ripening is also earlier in these regions than in north-western
parts.
- In the south under moderate temperature conditions even during winter
the flowering may start in September or as late as November.
- At Kanyakumari some of the varieties flower and fruit twice a year.
- This is known as off-season bearing which may primarily
be conditioned by the differences in night and day temperatures
and also humidity.
- The annual mean temperature at which mango thrives best is around
26.70 C.
- The optimum growth temperature for mango is 23.90 - 26.70
C.
- Temperature plays a direct role on the flowering, fruit set and fruit
development in mango.
- Under Bangalore (India) conditions mangoes use to flower during November-December
months during early 80s and is now shifted to late January.
- This may be due to diurnal variation in temperature and relative humidity.
- When atmospheric temperature was high, fruits exposed to direct sunlight
were normally affected with spongy tissue disorder.
- Air temperature of over and above 40.50 C develops spongy
tissue in Alphonso mangoes.
- Exposure of fruits on western side is more dangerous as the fruit
on that side getting direct sun rays for longer period are more likely
to have spongy tissue.
- Though fruit splitting in mango is a very rare phenomenon,
it is related with variation in maximum and minimum
temperature and relative humidity between day and night
time.
- Under Bangalore conditions fruit splitting was around 2 per cent,
specially at later stages of fruit development in varieties like, Langra
and Amrapalli.
- It may be due to variation in day and night temperature and relative
humidity.
- After fruit splitting secondary infection occurs in the split portion
of the fruit making it unfit for consumption.
Rainfall
- It is not the quantum of rainfall but the timing which is of importance
in growing mango.
- In India, mango grows equally well both under low and heavy rainfall
of 25-250 cm annually.
- However, with the annual rainfall of 75 cm and above it can be grown
with little or no irrigation.
- One of the Pre-requisites for successful growing of mango is the absence
of rain during the flowering time.
- Rain at flowering not only washes away the pollen, which adversely
affects fruit set, but also encourages greater incidence of mango hoppers,
mealy bugs and diseases like powdery mildew and anthracnose, which damage
the crop sometimes completely.
- Cloudy weather with resultant increased humidity in the atmosphere
also encourages greater incidence of such pests and diseases.
- This also interferes with the activity of pollinating insects, thus
adversely affecting fruit set.
- In areas of excessive rainfall and high humidity even during the time
of fruit maturity, as in Assam, commercial mango growing may not be
profitable due to the attack of fruit fly.
- If high temperature, rainfall and humidity persist throughout the
year, there will be no distinct phases of vegetative growth and flowering
in the mango tree and bearing will be poor.
- In the coastal region of Kerala, which has restricted export of mango
to the USA, mango gets infested with stone weevil.
Frost
- Mango is adversely affected by frosts and freezes if not properly
protected.
- The damage depends on several factors, such as the age of the tree,
moisture content of the soil, condition of growth, timing, severity
and duration of the frost.
- Generally, young trees with immature wood and those having active
growth are affected more severely than the well-grown trees with mature
wood and those in dormant condition.
- Trees identical in growth and age and growing on dry soils are also
severely damaged as compared to those growing in wet land.
- The irrigation raises the soil temperature and provides protection
against mild frosts.
- Early and late frosts cause more damage than the mid-season frosts
of the same severity.
- The trees are affected more severely by the former as they are not
fully dormant, while in the latter case damage occurs owing to reinitiation
of growth and tenderness of the tissues.
- Front injury is exhibited through bark splitting, but this is not
visible in the young plants.
- Oozing of gum from stem bark, death of new shoots, charred appearance
of leaves and burning appearance of developing fruit buds are the other
symptoms of frost injury.
- If the temperature is below1.10 C, the mango plants are
adversely affected by frost.
- A short spell of -3.30 C and consequent longdrawn out
cold spell led to the drying out of the young shoots and leaves of mango
plants, killing the tree from the top down to a point where the bark
was thick and the sap moved very slowly.
- The young mango trees in vigorous growth may be injured seriously
at 00 C.
- The minimum temperature of -0.6 to 00 C for 1 hr 15 min
for 2 consecutive days resulted in appreciable damage to mango trees.
- All 1-year-old plants, though protected, were killed completely.
- Similarly, all 2-year-old plants were found adversely affected and
some of these could not survive. Four-year-old plants were partially
affected.
- Differentiating and exposed fruit buds in bud-break and bud-burst
stages were killed outright.
- The turned blackish and dropped down.
- For protection against frosts, the young mango trees should be covered
fairly early and the thatchings should be removed only when the danger
is over.
- Some growers remove the covers too early, with the first warming up
of temperatures after winter; but the trees are likely to suffer if
late frosts occur.
Wind
- Exposure to strong winds, whether hot or cool is harmful
to mango crop.
- In fact high velocity of wind affects mango trees
in several ways.
- Winds of high velocity lead to quick evaporation of
water from the soil and thus reduce moisture availability
which is very much necessary for ideal growth and development
of the plant.
- Mango trees normally assume a dome shaped top and
are less prone to wind damage, such as, breaking of
limbs, branches, fruit drop etc.
- Strong winds, gales or storms blow away the branches,
leaves or panicles and sometimes fully grown trees also
get toppled.
- It is more so in the areas adjascent to coast or open
areas that are not fully protected with windbreaks.
- Dwarf mango varieties like Amrapali, Rumani and Kerala
Dwarf are less prone to wind damage compared to tall
and huge trees like Pairi and Langra.
- High velocity of wind may uproot the whole tree.
- This problem is commonly noticed in areas frequently
affected with heavy cyclone specially in Nellore, Krishna,
Ranga Reddy and Viskhapatnam districts of Andhra Pradesh
and Kanyakumari district of Tamil Nadu.
- Fruit drop at various stages of its growth can be
noticed due to high velocity of wind.
- Under Bangalore conditions wind velocity of more than
120 km per hour damaged the Pairi variety mango trees
by breaking the limbs.
- At later stages of fruit development this problem
was severe due to heavy weight of the fruit.
- This necessitates the raising of live, thick and strong
windbreaks around the mango orchard.
- Seedlings of Casuarina, silver oak or Acacia
are some of the ideal windbreaks for mango garden.
- These wind breaks may compete with the mango crop
for nutrients and moisture.
- Thus a trench of half a meter width and half to one
meter depth should be dug open between the mango tree
rows and windbreak.
Hailstorms
- Occurrence of hailstorms is a natural phenomena and it causes partial
or total loss of mango crop.
- The hailstorms occur sporadically and that to during the pre-monsoon
showers.
- The damage caused to fruit is by physical hitting of hailstorms, which
leads to rupture of tissue and such areas get discoloured and start
rotting.
- Secondary infection by fungus starts sometime after the physical damage.
- Affected fruits do not ripe and are unfit for consumption.
- Such fruits are not even fit for pickling.
- There is hardly any method to protect this damage.
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