Climate
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- But, for ensuring the development of a profitable and prosperous coconut industry, it is necessary that the likes and dislikes of the palm are given due consideration, particularly when establishing plantation in new regions where it was not grown before.
- In fact, it is highly adaptable to a variety of environments.
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- The coconut palm is not very fastidious or exacting in its climatic requirements.
- The coconut palm derives its characteristics from the fact that it is essentially a tropical plant.
- In these connection factors such as latitude, rainfall, temperature, humidity, sunshine, etc., require detailed consideration.
Latitude
- The coconut palm occurs widespread in the tropics.
- The six primary centres of coconut cultivation, viz., Philippines, India, Indonesia, Ceylon, South Sea Islands and Malaya which together account for over 90 per cent of the world's total acreage and production of the crop lie in this zone between 200N and 200S latitudes.
- The palm is being grown even beyond this region, as far as 270N and 270S, but not on an extensive or commercial scale or with much success.
- In these extreme latitudes the palm is reported to put on good vegetative growth, but not to bear fruits satisfactorily.
Altitude
- The limits to altitude upto which coconut can be grown successfully are set by the latitude also.
- In India, flourishing coconut plantations are met with in parts of Mysore State situated at elevations of 600 m to 900 m above sea level.
- Generally coconut may be possible to grow at elevations higher than 600 m to 900 m in areas near the equator, where the temperature remains favourable for coconut growth.
Rainfall
- Of all the climatic factors affecting the coconut, rainfall and temperature appear to be the more important ones.
- While temperature conditions may be uniform over comparatively large areas, rainfall will show considerable variation even within short distances.
- The coconut palm can grow and bear fruits with a well distributed rainfall of 100 cm but for profitable cultivation, 100 cm to 225 cm per annum, evenly distributed throughout the year appear necessary.
- It can stand even much higher precipitation if the soil is well drained.
- As the tree stores little moisture and has no tap roots, it is not suited for regions with long and pronounced dry spells during which the water table goes down considerably.
- On the other hand, a water table that is too high and remains stagnant over long periods is definitely harmful to the palm.
- On the West Coast of India wherein lies the major coconut belt, rainfall increases in quantity, from the south to north; but its distribution becomes less and less favourable.
- Thus in Travancore, situated in the south, the annual rainfall is 300 cm or less per annum, but the dry period extends to only two or three months in the year, whereas in the South Kanara District, further north, the annual rainfall is about 350 cm, with the dry or rainless period extending over about five months.
- This difference in the distribution of rainfall is actually reflected in the general productivity of the crop.
- It may be stated in a general way that when the total rainfall falls below 100 cm per annum or where the rainfall distribution is very uneven, the coconut can be grown successfully only under irrigation.
- In parts of Saurashtra and Kutch (India), receiving only 25 cm to 50 cm of rainfall per annum, good coconut garden have been raised because of the availability of abundant supply of sweet water for irrigations.
Temperature
- Temperature is another important weather factor that has great influence on the growth and productivity of the palm.
- In fact it is temperature that actually determines the limits to latitude and altitude.
- The palm requires an equable climate, neither very hot nor very cold.
- The optimum mean annual temperature for best growth and maximum yields is stated to be 270C with a diurnal variation of 60C to 70C.
- Nowhere is the palm being grown extensively where the range of temperature is considerable.
- On the West Coast of India, the monthly mean of the minimum temperature does not fall below 200C and the monthly mean maximum rarely goes over 320C.
- High temperatures might cause the young developing inflorescences to dry up, and limit production to those months in the year when the temperature remains at a satisfactory level.
Humidity
- The coconut palm, in general, likes a climate characterised by warm and humid conditions.
- Highly humid conditions are not considered good for the palm from two aspects.
- One is that it reduces transpiration and thereby reduces the uptake of nutrients.
- The other is that it provides congenial conditions for the rapid spread of the fatal diseases of the palm, viz., 'bud-rot' etc.
- The leaf disease of the coconut palm in Kerala (India) is found to spread rapidly during rainy months when the atmospheric humidity is high.
- In Sumatra, too high humidity is reported to cause premature decay of fruit.
Sunshine
- The palm requires plenty of sunlight and does not grow well under shade or in too cloudy regions.
- The lean and lanky growth and unproductiveness of palms growing in shade and the way they try to turn away from obstruction to expose the crowns to the sun, afford sufficient evidence of the avidity of the palm for sunlight.
- Sunlight has also been shown to raise the temperature of the leaf surface and thereby to promote better activity in the tree.
- The importance of sunlight is the synthesis of organic food materials by the chlorophyll of green plants.
Wind
- Dry and windy atmosphere conducive to the best growth of the palm provided soil moisture conditions remain at optimum level, but that where the soil is dry, only little wind is desirable.
- Windiness increases the transpiration rate and helps in the uptake of more nutrients in the soil solution.
- But regions which are subject to frequent violent winds do not appear to be quite suitable for growing the palm.
- Violent storms cause considerable damage to coconut plantations.
- They not only uproot or break the trees but also twist the crown or break the leaves and destroy a considerable part of the crop.
Nearness to sea
- The fact that coconut palm is largely being grown in regions bordering the sea coast has often created a mistaken impression that the palm will not thrive inland.
- However, nearness to sea has considerable effect on the climate as well as on the soil.
- The coastal climate is always more humid and less subject to wide fluctuations of temperature and these conditions are favourable to the palm.
- In the coastal areas, the growth of the coconut is excellent while it is comparatively poor in the interior.
- Another favourable feature of coastal areas is that they generally posses better sub-soil water supplies than those in the interior, because they have at the back of them, higher country and the rain which falls there partly sinks into the soil and moves towards the sea brining with it dissolved nutrients for the palm's nourishment.
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