Agro-Ecology

Arecanut

Soil and climate requirements of coconut, arecanut, and cocoa are described in this page

Coconut

Coconut palm is highly adaptable and performs well under a range of environmental conditions.  However, best yields are realized under the following conditions.

Climate

• Temperature: Mean annual temperature of 27°C with a diurnal variation of  5-7°C is ideal - temperature <15°C results in abnormalities of the fruit

• Rainfall:  1800 to 2500 mm/year, well distributed; - can withstand very high rainfall in well drained soils - irrigation essential in areas with low rainfall and poor distribution - can withstand occasional water logging.

• Insolation:   120 hours of sunshine per month; 2000 hours or more per year.

• Humidity:   80-90% RH ideal. RH below 60% affects opening of stomata.

• Altitude:  Generally less than 600m, can be grown at higher elevations if  nearer to equator.

  Soil

The best coconut soils are characterized by an open texture (such as deep alluvium and sandy loam), good drainage,adequate supply of soil moisture and nutrients, ideal pH of 6.0–7.5 and at least 1m depth without any hard layers. In India, coconut is mainly grown in laterite, coastal sand, red sandy loam, coral and alluvial soils.  These soils come mainly under four soil orders viz.  Alfisols, Entisols, Ultisols and Inceptisols.  These are mainly acidic in nature with low fertility status and they suffer from varying degree of nutrient/moisture stress.  The CEC of these soils is very low, thereby, leading to low retention of cations like K, Ca, Mg etc.  The tropical acid soils are in a fortunate position with respect to the cationic elements Fe, Mn, Cu and Zn.  These cations are easily soluble and readily available under acid conditions and are not generally found limiting in the nutrition of the palm.

  Arecanut

  Climate

The cultivation of arecanut is mostly confined to 28º north and south of the equator.  It grows well within the temperature range of 14ºC and 36ºC and is adversely affected by temperatures below 10ºC and above 40ºC.  Extremes of temperature and wide diurnal variations are not conducive for the healthy growth of the palms.  Arecanut can be grown in areas receiving annual rainfall of 750 mm in Maidan parts of Karnataka to 4,500 mm in Malnad areas of Karnataka.  In areas where there is prolonged dry spell, the palms are irrigated.  Due to its susceptibility to low temperature, a good crop of arecanut cannot be obtained at an altitude of more than 1000 m MSL.

  Soil

The largest area under the crop is found in gravelly laterite soils of red clay type.  It can also be grown on fertile clay loam soils.  Sticky clay, sandy, alluvial, brackish and calcareous soils are not suitable for arecanut cultivation.

  Cocoa

  Climate

Cocoa is grown between 20°N and 20°S latitude, but maximum areas are situated between 10°N and 10°S latitude.  Cocoa can be grown up to 300 m above mean sea level.  It requires a minimum of 90-100 mm rainfall per month with an annual rainfall of 1500-2000 mm.  The plants need equitable climate with well distributed rainfall.  If dry periods are prolonged, irrigation scheduling is necessary.  The temperature range of 15°-39°C with optimum of 25°C is considered ideal.

  Soil

Cocoa requires deep and well drained soils.  Poorly drained soil affects growth of plants. Majority of area under Cocoa cultivation is on clay loam and sandy loam soil.  It grows well in the pH range of 6.5 to 7.0.

  Shade requirement

Cocoa was evolved as an under-storey crop in the Amazonian forests. Thus commercial cultivation of cocoa can be taken up in plantations where 50 per cent of light is ideally available.  In India, coconut and arecanut gardens are suited best for cultivating Cocoa.  Under arecanut 30-50% of sunlight penetrates through their canopy which can be intercepted by cocoa.