Tải bản đầy đủ - 0trang
D. Establishing a Cardamom Plantation
THE AGRONOMY AND ECONOMY OF CARDAMOM
the field for longer periods, too close planting will lead to overcrowding and
yield reduction. This is important since cardamom clumps tend to spread
outwards as they age and gradually new shoot production will decline in the
center of the plant. It will also lead to yield reduction as the crop ages.
Korikanthimath (1983b) investigated the eVect of spacing, seedling age, and
their performance in relation to fertilizer rates and found that tiller number,
number of leaves per plant, and plant height were significantly aVected by
the diVerent treatments. Maximum tiller number (10.9 per plant) and maximum number of leaves (102.1 per plant) were seen in the case of 18‐month‐old
seedlings planted at 2 m Â 1 m spacing and the plants were fertilized with N, P,
and K in the ratio of 75:75:150 kg haÀ1 and a supplemental 100 kg haÀ1 neem
(Azadirachta indica) cake. In another similar investigation, where spacing and
fertilizer rates were considered, under rainfed conditions, the treatment diVerences turned out to be highly significant inasmuch as tiller number and leaf
number per plant were concerned. A spacing of 2 m Â 1.5 m combined with a
fertilizer schedule of 75:75:150 kg N, P, and K per hectare resulted in maximum tiller number and leaves per plant (Korikanthimath, 1982). Normal
spacing adopted in the case of the vigorous variety Mysore is 3 m Â 3 m, and
for the less vigorous variety Malabar 2 m Â 2 m spacing is adopted (Anon,
1976). In the ‘‘high‐production technology’’ field demonstration plots, primarily meant to show the farmers, spacing at 2 m Â 1 m on hill slopes along
the contour and spacing at 2 m Â 1.2 m on flat lands, gentle slopes, and valley
bottoms, yielded 500 kg dry capsules haÀ1 within 2 years from the date of
planting (Korikanthimath and Venugopal, 1989). In a spacing trial carried out
at Yercaud, in Tamil Nadu, it was observed that close spacing at 1 m Â 1 m
and 1.5 m Â 1.5 m resulted in better yield per unit area than in the case of wider
spacing at 2.5 m Â 2.5 m and 2 m Â 2 m. In slopy lands, it is advisable to make
contour terraces in advance of the planting date and pits may be dug along
the contour for planting. Depending on the slope, a distance of 4–6 m may
be provided along the slope between the contour lines. Close planting may be
adopted along the contour.
Methods of Planting
The factors which determine the planting systems are the land, soil fertility,
and the probable period over which the plantation is expected to last. Seedlings are planted in holes in some places, which are scooped out at the time
of planting. In other areas, considerable care is taken in preparing pits
for planting. Spots where pits are to be dug are marked with stakes, soil
dug out from the pits, and they are filled with surface soil mixed with leaf
mould, compost, or cattle manure (Subbaiah, 1940). Commonly pit size is
60 cm Â 60 cm Â 45 cm. Some plantations use pit size of 90 cm Â 90 cm Â
K. P. PRABHAKARAN NAIR
90 cm or 120 cm Â 120 cm Â 30 cm. In South and North Kanara in the State of
Karnataka, pits are of smaller size, namely, 45 cm Â 45 cm Â 45 cm (Mayne,
1951a). In the State of Kerala, varieties Mysore and Vazhukka are planted in
pit size of 60 cm Â of 45 cm Â 45 cm. Normally pits are opened during the
months of April–May, after the premonsoon showers. Pits are filled with a
mixture of top soil and compost or well‐rotten farm yard manure and 100 g of
rock phosphate. In slopy land, contour terraces are made suYciently in
advance of planting and the pits are dug along the contour (Anon, 1985,
1986). Most of the cardamom‐growing tracts are situated on hill slopes of
Western Ghats. The undulating terrain and heavy rainfall in the region
increase the problem of soil erosion and loss of plant nutrients in run oV.
This implies the need to conserve enough moisture, while at the same time,
ensure safe disposal of excess rainfall. In view of these pressing demands,
investigations under rainfed conditions on planting‐fertilizer treatments were
carried out at Cardamom Research Center at Appangala, Karnataka State,
under the administrative control of the Indian Council of Agriculture Research. These investigations were started in 1985. Some of the results are
included in Table XVI. Korikanthimath (1989) reported greater moisture
retention under the trench system of planting than in the case of pit system
of planting and concluded the former to be better than the latter.
Trenches may be dug to a depth of 30 cm Â 45 cm wide up to any length
across the slope or along the contour. Top 15 cm soil may be removed and
kept separately, while the lower 15 cm soil excavated from trenches placed
below the one above. The top 15 cm soil is filled back into the trench with
cattle manure. While closing the trench, about 5 cm space may be left at the
top to facilitate application of fertilizers and mulches. Although digging
trenches would be about 30–40% more expensive than digging pits, it may
be worth attempting because of the benefits of soil moisture conservation
and its ultimate beneficial eVect on plant growth and yield. However, in low‐
lying areas, where the danger of water stagnation is real, pit system may be
Dry Cardamom Yield (kg/ha) Influenced by Planting System and Fertilizer Rates
NPK fertilizer (kg haÀ1) (B)
Planting system (A)
Notes: SE/Plot: 88.0; general mean: 356.5; CV (%): 24.7 CD for (A): 57.1; CD for (B): 90.3; CD
for (A) Â (B): 127.7.
THE AGRONOMY AND ECONOMY OF CARDAMOM
a. Planting Season. Two most important factors, which determine
planting season, are topography and pattern of rainfall. Commonly planting
is done in June–July months. Where southwest monsoon is torrential, planting is completed either before July or is taken up in August–September when
the rains cease. Better crop establishment and growth are ensured through
early planting as compared to late planting (Mayne, 1951a). In low‐lying
valleys planting should only be commenced after July when torrential rains
begin to abate (Korikanthimath, 1980). In Mudigere district of the State of
Karnataka, better establishment and crop growth were reported when
the planting was done in the month of August (Pattanshetty and Prasad,
1972). Cardamom suckers are planted from June through August on the soil
surface or 15‐ to 20‐cm deep. With surface planting, mortality of seedling is
least, and when rainfall is relatively less heavy in the week following planting. Suckers planted in August survived best, with a mean mortality rate
of 25% and those planted on soil surface showed the lowest mortality rate of
17.5% (Pattanshetty et al., 1972, 1974).
Investigations on the eVect of monthly planting were carried at the
Horticulture Research Station in Yercuad, Tamil Nadu, which is located
on the eastern side of the Western Ghats along the State of Kerala. Planting
was commenced from June through November during 3 years, to assess ideal
planting time at elevations of about 1300–1500 m amsl. Best establishment
(87.92%) was obtained in July planting, followed by August, September,
October, and November planting with establishment rates of 77.9%, 75.4%,
63.7%, and 61.6%, respectively. June planting gave only 19.4% establishment. To obtain good establishment, a total rainfall of at least 322 mm has
to be there, while the minimum and maximum temperatures should be in the
range of 15.5–17.5 C and 19.5–25.0 C, respectively during the month of
planting (Nanjan et al., 1981).
b. Planting. The general practice is to scoop a small depression in the
filled soil and the seedling is placed at the center of the depression. Soil is
then replaced taking care not to disturb the roots in their normal position
and pressed well around the base of the clump. Deep planting should be
dispensed with as it results in suppressing growth of the young seedling and
emergence of new shoots, which may lead to decay of underground rhizomes. Seedlings are normally planted at an acute angle to the soil level to
prevent them being broken or blown by strong winds, which follow the
planting season (Anon, 1952a). Light pruning is desirable, but this should
only be confined to longer roots, avoiding shorter ones, of 0.3 m or more. In
the case of rhizome planting, the planting material can be kept in pits in a
slanting manner and rhizomes covered with soil as in the case of seedling
planting. Following planting immediately, seedlings should be physically
supported by stakes to prevent damage or being blown away by strong
K. P. PRABHAKARAN NAIR
wind and a mulch cover with dry leaves is provided at the base. Criss‐cross
staking with two stakes is the best practice to follow. Plants may be loosely tied
to the stakes with dried banana sheath or jute threads to facilitate emergence
and growth of aerial shoots. Care must be ensured to oVset after transplantation shock, which emanates because of physical reasons, and the seedling must
also be guarded against heavy rains. Unhealthy plants are prone to disease
infestation, and it would be advisable to spray the seedlings with 1% Bordeaux
mixture or any other suitable fungicide, as a prophylactic measure. The newly
planted area should be inspected periodically and gaps when found should be
filled instantly, if the climate is favorable.
c. Planting of Suckers. Propagating cardamom using suckers consists
of splitting up established clumps into sections consisting normally of at
least one old and one young shoot. Planting material of 20‐cm long rhizome
results in more shoots per clump, early bearing, and large net returns than
short rhizomes of 2.5 cm (Pattanshetty, 1972a,b; Pattanshetty et al., 1974;
Pillai, 1953 ). The section of rhizome is placed in a small depression in a pit
that is already prepared and covered over with soil and mulch. The leafy
shoots are placed almost parallel to the soil surface. A clump is constituted by
new shoots which arise from the rhizome. In the high ranges of Kerala State,
straight planting of rhizome with stake is recommended. In Guatemala, propagation of cardamom is invariably by suckers, where the dreaded disease ‘‘Katte’’
is not a threat (Anon, 1977). Three suckers per pit are used to induce tillering
in a short time span. Rapid growth and high‐yielding pattern are the essential
features of Guatemala which are mainly attributed to the conducive rainfall
distribution pattern. Fertile soils and good plantation management complement this. In India also, farmers have realized high yields where intensive
management practices have been resorted to, of which good irrigation is
an important component.
d. Gap Filling. Good initial establishment is crucial to raising a productive cardamom plantation. On average, 5% gaps are seen in most cardamom
plantations. Healthy and disease‐free seedlings or clumps can reduce seedling
mortality during establishment period. Monsoon failure during planting time
is a potential hazard, in which case supplemental irrigation, once a week, is a
must. It is advisable to use healthy, suYciently grown up seedlings, or preferably clonal materials for filling the gaps. May–June, when monsoon starts, is
the best time for gap filling. However, if this is missed, with proper care, gap
filling can be extended up to August–September. Success of gap filling
depends on after care until gap‐filled plants reach the state of earlier established plants. Regular cultural operations must be carried out after planting,
and these consist of regular mulching, weeding, trashing, raking/digging,
THE AGRONOMY AND ECONOMY OF CARDAMOM
irrigation, shade regulation, manuring, gap filling, and plant protection measures to maintain plants in a healthy and vigorous condition.
e. Mulching. Cardamom productivity is very much dependent on
proper moisture balance in the soil. In recent years in India, premonsoon
showers have become quite erratic, on account of global warming. This
results in cardamom plants facing drought even up to 6 months at a stretch.
Mulching is a practical solution to conserve soil moisture, and has been
acclaimed as the most important cultural operation for the overall improvement of soil and yielding capacity of cardamom plantations (Zachariah,
1976). Following are the advantages of mulching cardamom plantations.
1. By minimizing surface evaporation, soil moisture is conserved.
2. When rains occur soil does not get puddled because of the beating action
of the raindrops, the physical condition of the soil is maintained.
3. It checks run oV and erosion.
4. Both friability and soil structure are improved due to the enhanced biotic
activity under the mulch. Soil becomes more porous as the number of
macropores is increased by biotic activity. This helps in better water
percolation and moisture conservation.
5. An equilibrium of soil temperature is maintained.
6. Enrichment of soil organic matter leads to enhanced biotic activity with
its positive fallout on nutrient availability and soil fertility in general.
7. Weed growth is controlled.
8. Results in better root growth, which in turn, leads to extraction of soil
moisture from deeper layers.
9. Eventual decomposition of the mulch aVects soil fertility eventually.
Soon after planting, base of the plants is adequately mulched. Mulching is a
simple cultural operation in which dried leaves and other plant residues are
used. The mulching should be completed before the onset of summer. Leaves
shed by the shade trees come in handy for mulching which can de done in the
months of November–December. An investigation was conducted to study
the relative merit of locally available mulching materials such as dried leaves,
paddy husk, phoenix leaves, coir dust, and stratified leaf mulch under uniform
shade of coir matting and by using suckers of cv. P1 combined with two levels of
irrigation, namely, 75% and 25% available moisture. Results are in Table XVII.
Results did not show any significant diVerence on production of suckers due to
irrigation levels. Leaf mulch and phoenix leaves were at par, statistically, but
were found to be significantly superior to other mulches in the production of
suckers (Raghothama, 1979).
Demulching is equally important and should be carried out in May after
the premonsoon showers to facilitate honeybee movement in the plantations,
which will ensure better pollination and capsule setting. The practice of
K. P. PRABHAKARAN NAIR
EVect of DiVerent Mulch Materials on Germination of Cardamom Seeds
Dry leaves of rose wood
Phyllanthes emblica leaf twigs
LSD ( p ¼ 0.05)
Leaf spot disease
(%) 45 DAS
Note: DAS, days after sowing.
uncovering the panicles shortly after the commencement of flowering
improves fruit set. Average number of capsules per plant is 27.4 and 2.1,
respectively in the case of exposed and covered panicles in variety Malabar
(Pattanshetty and Prasad, 1974). The removal of mulch, which accumulates
in the center of the clump and thereby releasing panicles beneath, would not
only facilitate movement of honeybees, but will also provide better aeration
and minimize incidence of clump rot and rhizome rot disease.
Since the cardamom plant gets its nutrition from the top layers of the soil,
it is crucial that in the first year of planting frequent weed control is done to
avoid root competition between young cardamom seedlings and weed, as
both can compete for nutrients and moisture. Weeding is carried out either
on the entire area covering the plants or on just around the plants. It is called
ring weeding. The weeds are used as mulch for young plants. As many as 21
dicotyledonous weeds are identified in cardamom estates in the Coorg
district of Karnataka State. Of these, Strobilanthes ureceolaris Gamb is the
most common. Weeds are controlled mainly by hand weeding, only in rare
instances are chemicals used. Two to three rounds of weeding are essential in
the first year of planting to remove regenerating undergrowth. Generally, first
THE AGRONOMY AND ECONOMY OF CARDAMOM
hand weeding is done in the months of May–June, the second in August–
September, and the third in December–January. When weeding is done in
May–June and August–September, the weeded matter are heaped in the interrow spaces and are later used for mulching. In November–December when the
weeding is done, the matter is directly utilized for mulching. Slash weeding is the
most common in cardamom plantations. Spraying Gramaxone at the rate of
1.5 ml literÀ1 twice a year is also resorted to in some plantations, although
infrequently, and this practice is quite economical and convenient.
Additional Field Operations
These are trashing, raking, digging, and earthing up. Trashing consists of
removing old and drying shoots. Beginning second year of planting, trashing
has to be continued every year. Trashing promotes better sunlight penetration
and aeration, thereby promoting tiller initiation and plant growth as well as
reduction in thrips and aphids infestation. It also helps in better pollination by
honeybees (Korikanthimath and Venugopal, 1989). In rainfed areas, trashing
time is May, after the receipt of premonsoon showers. The trashed leaves and
leafy stems may be heaped between the rows and allowed to decay or used for
composting. A light raking or digging of soil around the clump up to a radius
of 75 cm is done toward the end of the monsoon. The soil mulch formed
around the plant base helps conserve moisture during the following period.
This practice is particularly useful in low‐rainfall areas. Digging not less than
25‐cm deep, once in alternate years, may be done in the entire area, followed
by the application of farmyard manure or any other organic manure, such as
bone meal, stera meal, groundnut cake, and so on. Digging can also be done
in patches; it is, however, necessary to dig each year if the soil is clayey
(Kuttappa, 1969b). Toward the end of the rainy season a thin layer of fresh
and fertile soil rich in organic matter may be spread at the base of the clump
which covers up to the collar region. This soil is obtained by scraping in between
the rows or collecting the same from the trenches or pits. The thin layer of soil
applied in the center of the clumps will not only keep them intact and cover the
exposed roots, but also will check the ‘‘walking’’ habit (radial growth) of the
cardamom plant (Korikanthimath and Venugopal, 1989). Care must be taken
not to heap the soil above the collar region of the clump.
Replanting in the Plantation
Decline of yield is a problem in cardamom, although it is a perennial crop.
Once in 8–10 years, regular replanting has to be done to ensure high productivity. One of the main reasons for low‐average cardamom yield in India is on
K. P. PRABHAKARAN NAIR
account of the fact that there are many old plantation where no replanting has
ever been made (Korikanthimath et al., 1989). Clonal material from superior
high‐yielding varieties may be used for replanting, which will ensure that the
yields are high. Korikanthimath et al. (2000a) investigated the economics
of replanting. The authors replanted a cardamom plantation after a period
of 10 years using the trench system of planting and maintained the replanted
plantation with all the recommended inputs—fertilizers, irrigation, and so
on—as per the package of practices recommended in the ‘‘high‐production
technology’’ (HPT). Planting materials used were 10‐month‐old seedlings
from high‐yielding mother plants. The replanted field gave 155 kg of dry
cardamom in the second year. In the following year a record yield of 1775
kg haÀ1 was obtained. In the subsequent 3 years dry yield obtained was
385, 560, and 870 kg haÀ1, which averaged 749 kg haÀ1 yearÀ1. Economic
analysis carried out by Korikanthimath et al. (2000b) showed a net return
of Rs 2, 03, 465 haÀ1 (which is approximately US$4800 at current rate of
US$–Indian rupee exchange) and the benefit–cost ratio (BC ratio) worked out
to 2.78. The investigation conclusively demonstrates that replanting a cardamom field after a 10‐year gap is economically advantageous.
Both by seeds and through vegetative means can cardamom be propagated. Seedling population is variable because cardamom is a cross‐
pollinated crop. Hence, vegetative propagation is only adopted in the case
of elite clones. Both micropropagation (tissue culture) and rhizome bits
(suckers) can be used for vegetative propagation. With commercialization,
micropropagation has become quite popular in cardamom production.
Propagation Through Seeds
In order to obtain quality seedlings, cardamom nursery has to be managed carefully and scientifically. This involves sowing seeds on raised beds,
transplanting into primary and then on to secondary nursery beds and
finally into the field (Cherian, 1979; Kasi and Iyengar, 1961).
Seeds should be collected from high‐yielding vigorous plants, with well‐
formed compact panicles and well‐ripened capsules free of pest and disease
infestation. Number of flowering branches formed on the panicles, percentage
of fruit set, and number of seeds per capsule should be given due consideration
THE AGRONOMY AND ECONOMY OF CARDAMOM
while selecting the number of plants for seed collection (Anon, 1979; John,
1968; Ponnugangum, 1946; Siddaramaiah, 1967; Subbaiah, 1940). Apart from
these desirable attributes, the mother clump should have more number of tillers
(shoots) per plant, leaves with dark green color, and high percentage of fruit set.
Color of capsules should be dark green (Krishna, 1968). On average, 1 kg of
fruits contain 900–1000 capsules with 10–15 seeds per capsule. Taking into
consideration the percentage of germination, mortality due to diseases, and
so on, on an average 1 kg of seed capsules are required to obtain about 5000
Preparation of Seeds
Seeds for sowing are collected from fully ripe capsules preferably from
second to third round of harvest and are then either washed in water or sown
immediately or mixed with wood ash and dried for 2–9 days at room temperature. The first method gives better results and is adopted widely. Following
picking, seed capsules should be immersed in water and gently pressed for
separating seeds and washed well in cold water to remove mucilaginous
coating on the seeds. After draining water, seeds should be mixed with ash
and surface dried in shade.
Viability of Seeds
Stored seeds lose viability over time, and this would result in delayed
germination, or sometimes, no germination at all. Seed germination was
found to be 59% and 50.6% in varieties Mysore and Malabar, respectively
(Korikanthimath, 1982). Germination was reduced when stored seeds were
used, especially those stored in airtight containers. Seeds treated with organomercurials and stored in open bottles would germinate up to 4 months.
Highest germination of 71.8% was observed when sowing was done in
September (Pattanshetty and Prasad, 1973; Pattanshetty et al., 1978). In a
clone of variety Malabar germination gradually declined. Seeds sown 60
days after storage, at fortnightly intervals starting August up to 14th of
October, showed progressive decline in germination—56.7%, 51.0%, 46.4%,
34.1%, 32.5%, and 29.6%.
When sown immediately after in September, germination was uniform
and early and are ready for transplantation at the end of 10 months. If they
are further retained in nursery beds for the next planting season either by
proper thinning or by transplantation at wider spacing in secondary nursery
beds, they develop rhizomes with large number of tillers and are ideal for
field planting (Pattanshetty and Prasad, 1972). November–January has been
K. P. PRABHAKARAN NAIR
found to be the ideal sowing time for Kerala State and for Tamil Nadu and
Karnataka, it is September–October (Anon, 1970, 1979).
Presowing Treatment of Seeds
Cardamom seed possesses a hard seed coat, which delays germination.
Investigations have been carried out to study the eVect of presowing treatments of seeds to oVset delay in germination. Treatment of freshly extracted
seeds with concentrated nitric acid or hydrochloric acid for 5 min significantly
improved the germination of seeds sown during November (Pattanshetty and
Prasad, 1974; Pattanshetty et al., 1978). Treating the seeds with 20% nitric
acid, 25% acetic acid, and 50% hydrochloric acid for 10 min was found to show
97.6%, 98.6%, and 91.5% germination, respectively. Korikanthimath (1982)
found treating with 10% nitric acid to be the best for enhancing generation.
Ambient temperature also plays an important part in germination. Low ambient temperature in the winter in cardamom‐growing areas not only reduces
germination but also delays it (Krishnamurthy et al., 1989a). Gurumurthy and
Hegde (1987) found that germination is significantly correlated with maximum
and minimum temperatures prevalent in the area.
It is always preferable to select nursery site on gentle slope which has an
easy access to a perennial source of water. The nursery area should be cleared
of all existing vegetation, stumps, roots, stones, and so on. Raised beds are
prepared after cultivating the land to a depth of about 30–45 cm. Usually beds
of 1‐m width and convenient length and raised to a height of about 30 cm are
prepared for sowing the seeds. A fine layer of humus rich forest soil is spread
over the beds. The beds, when treated with formaldehyde solution (4%) are
found to control ‘‘damping oV,’’ another important disease of cardamom
(Anon, 1985). After this treatment the beds are covered with polythene sheets
for a few days and seeds are sown 2 weeks after treatment. Before sowing, beds
have to be flushed with water to remove any remaining formaldehyde.
Seed Rate and Sowing
The seed rate is 2–5 g to raise 10‐month‐old seedlings and 10 g to raise 18‐
month‐old seedlings (Anon, 1976, 1986). Seeds are sown in lines, usually not
more than 1‐cm deep. Rows are spaced 15 cm apart and seeds are sown 1–2 cm
apart within the row. For better and quicker germination deep sowing should
be avoided. Lindane at the rate of 60 g/5 m2 is to be used to dust seedbeds to
THE AGRONOMY AND ECONOMY OF CARDAMOM
prevent termite attack. After sowing a thin layer of sand or soil is spread over
the beds and pressed gently with a wooden plank, and a thin mulch of leaves
may be provided. Thereafter beds are to be watered everyday. Germination
will start after 1 month and may continue for a month or two more. Soon after
germination commences, the mulch is removed and shade is provided to
protect the young seedlings from direct sunlight and rain.
Mulching of Nursery Beds
Germination is influenced by mulching (Abraham, 1958). Using locally
available mulch materials, Korikanthimath (1980) carried out investigations
on the eVect of mulches on germination. The materials used were paddy
straw, paddy husk, dry leaves or rose wood tree, saw dust, wild fern, coVee
husk, goose berry (Phyllanthes emblica) leaves, sand, charcoal, polythene
sheet. Maximum germination (40%) was observed in the case of paddy straw
mulch when seeds were sown in September and this treatment was statistically
at par with that of rose wood tree dry leaves (37%) and wild fern (38%, refer
Table XVIII). There are also other reports which show that mulching with
coconut coir dust, paddy straw, or goose berry leaves enhances germination
(Korikanthimath, 1983a; Mayne, 1951a; Sulikeri and Kologi, 1978).
In the States of Kerala and Tamil Nadu, the seedlings are transplanted to
secondary nursery beds when they are about 6‐month old, whereas in the
State of Karnataka, the practice is to sow the seeds in the primary nursery and
Mean Cardamom Yield (g per Plant) Under DiVerent Shade Trees
Name of the
Note: SE for species ¼ 57.5, CD; LSD p ¼ 0.05 ¼ 18.
SE for years ¼ 49.4, CD; LSD p ¼ 0.05 ¼ 15.
CD for any 2 years for any species ¼ 31; CD for any two species for any years ¼ 32.