Cultivation
Planting
The plants may be planted by square system since
all the cultural operations can be performed more conveniently. Planting
distance should be maintained depending upon soil type and climate. A spacing
of 4–5m on marginal and very light soils is recommended. In subtropical
regions, planting may be done in spring (February–March) provided irrigation
facilities are available. However, July-August is ideal time of planting in
tropics.
Pits of 60cm × 60cm × 60cm size are dug about a
month prior to planting and kept open under the sun for a fortnight. About 50g
of 5% BHC or Carbaryl dust is dusted on the bottom and sides of the pits as a
precaution against termites. The pits are filled with the top soil mixed with
20kg farmyard manure and 1kg superphosphate. After filling the pit, watering is
done to allow soil to settle down. Cuttings/air-layers are then planted and
staked. Water them immediately after planting and repeat whenever necessary.
In temperate regions, high-density planting is
advocated. A spacing of 5–6m in northern India and even in plains in Deccan
plateau is optimum. Since pomegranate is normally cultivated on light to medium
soils in Deccan plateau, it responds well to pruning. The spacing has been
brought down to 4.5m which is optimum. The high-density plantation—5m × 2m
(1,000 plants/ha), 5m × 3m (666 plants/ha), 5m × 4m (500 plants/ha) and 5m × 5m
(400 plants/ha)— gives 2–2.5 times more yield than the normal planting distance
(5m × 5m) in Deccan plateau. There is not much difference in size of fruit and
TSS : acid ratio. Therefore pomegranate should be planted at a close distance
to obtain higher yields. Depending on the growth of the orchard trees,
alternate plants could be removed after 6–7 years, maintaining a spacing of 5m
× 4m. However, farmers adopt a spacing of 2.5m × 4.5m. Closer spacing increases
disease and pest incidence.
Training
Pomegranate plants can be trained on a
single-stem or in multi-stem system. The single-stem training has its own
disadvantages. The plants have a tendency to produce ground suckers, making the
plant bushy. As such it is rather difficult to train the plant to a single
stem. The crop is highly susceptible to stem-borer and shoot-hole borer. Moreover,
this system is hazardous. Thus single-stem training is uneconomical for
commercial cultivation. Therefore multi-stem training is more prevalent in the
country. Allowing too many stems also comes in the way of intercultural
operation. The varying of stem number of 3–4 does not affect the yield
significantly in early years of bearing and a multi-stem training with 4–5
stems/hill is beneficial.
Pruning
Pomegranate plants do not require pruning except
removal of ground suckers, water shoots cross branches, dead and diseased
twigs and giving a shape to the tree. Pomegranate fruits are borne terminally
on short spurs, arising from matured shoots, which have the capacity to
bear fruits for 3–4 years. With advance in age they decline. A little thinning
and pruning of old spurs to encourage growth of new ones is required. Some
useful tips on pomegranate pruning are:
·
Fruitful and differentiated buds are located at
the distal portion of the branches.
·
Pruning of terminal portion of a branch lowers
down the total flower production.
·
Pruning does not affect sex ratio and fruit
quality.
·
Pruning affects significantly total fruits,
marketable and unmarketable fruits. Fruit size and yield of higher grade fruits
are more with high intensity pruning.
·
Pruning minimizes the bending of branches and
staking.
Manuring and fertilization
Pomegranate is a hardy fruit plant, growing
successfully in low fertile soils. Its productivity is greatly increased by the
application of manures and fertilizers. Both macro and micronutrients affect
its growth, development and productivity. Application of 10kg farmyard manure
and 75g ammonium sulphate to 5-year-old tree annually is adequate, whereas
application of 50kg farmyard manure and 3.5kg oil cake or 1kg sulphate of ammonia
prior to flowering is ideal for healthy growth and fruiting. The basal dose of
farmyard manure @ 25–40 cart-loads/ha besides the recommended doses of NPK
should be applied to non-bearing trees in 3 split doses coinciding with growth
flushes during January, June and September. From fourth year, the fruiting can
be taken. Then apply N in 2 split doses starting at the time of first
irrigation after bahar treatment and next at 3 weeks interval, whereas full
dose of P and K should be applied at one time. These should be applied in a
shallow circular trench below tree canopy not beyond 8–10cm depth. After
application fertilizers are covered with top soil and irrigated. In general,
application of 600–700g N, 200–250g P2O5 and 200–250g K2O/tree/year
is optimum.
Aftercare
Since pomegranate plants take 4–5 years to come
into bearing, intercropping is beneficial. Low-growing vegetables, pulses or
green manure crops may be intercropped. In arid regions, intercropping is
possible only during the rainy season, whereas winter vegetables are
feasible in irrigated areas.
In young orchard, season-wise appropriate
intercrops could be taken. However in a bearing orchard, the soil
management practices vary with the type of crop since pomegranate gives 3
flushes in a year. In arid conditions, generally mrig bahar is preferred so
that natural precipitation could be used for fruiting. Therefore, after
harvest, the orchard is left as such untilled under the cover of natural
grasses during summer. In May, orchard is tilled, fertilization is done and the
bahar is induced. During rainy season and until the harvest, keep the orchard
weed-free as its feeding roots are very shallow.
Conservation of soil moisture is quite essential.
It is possible through the use of soil covers. Black polythene mulch or
organic-matter mulch such as saw-dust, banana trash, paddy husk and groundnut
shells are good mulching materials.
Anti-transpirants such as 10% Kaolin, 10–5m
phenyl mercuric acetate, 1.5% power oil and 1% liquid paraffin are beneficial
in increasing its productivity
Bahar treatment or flower regulation
The pomegranate plants flower and provide fruits
throughout the year in central and southern India. However, it needs to be
thrown into rest period so as to enable prolific harvest at a given time.
Looking at patterns of precipitation, flowering can be induced during June–July
(mrig bahar), September–October (hasta bahar) and
January–February (ambe bahar). In areas having assured rainfall where
precipitation is normally received in June and continues up to September,
flowering in June is advantageous; where monsoon normally starts in August with
erratic pattern, flowering during August is beneficial; the areas having assured
irrigation potential during April–May, flowering during January can be taken;
and where monsoon starts early and withdraws by September induction
of flowering in October is possible. In Rahuri, flowering during
January–February is better in quality followed by October flowering.
Considering comparable yields, prices and irrigation needs it is recommended
that October cropping could be substituted for January flowering.
Irrigation
Although pomegranate is considered to be highly
drought tolerant, its plants respond very well to irrigation. However, water
requirement varies from season-to-season. For mrig bahar, first
irrigation should be given during mid-May followed by regular irrigation
until the onset of monsoon. In post-monsoon period copious and regular
irrigation is essential for better development of fruits and to avoid
fruit-cracking. For other bahars (seasons), weekly irrigation in summer
and bi-weekly irrigation in winter are advised. The check basin system of
irrigation should be followed. For arid and semi-arid conditions,
micro-catchments should be developed to harvest rainwater. For check basin or
surface irrigation system, higher fruit yield is obtained under 0.8 IW:CPE
ratio, which is increased to 1.0 during flowering and decreases to 0.8 during
fruit development. It further decreases to 0.6 during rest period.
Drip irrigation can also be followed to economize
water. The check basin requires 108 ha-cm of water, whereas drip with mulch
requires 40.31ha-cm the water saving being 44% in drip system and 64% when
sugarcane trash mulch is used in drip system. The application of water
equivalent to 20% wetted area is superior to surface method, the average annual
irrigation water requirement through drip method being 20cm. Saving in water
(43%) and increased yield (30–35%) are observed.
High salinity in soils and irrigation with saline
water affect normal fruit production in pomegranate. Irrigation with 6.5mmhos
for 8–10 months does not affect adversely the survival of pomegranate
Khog, whereas Jalore Seedless can tolerate up to 4.5mmhos.
Harvesting and
Postharvest management
Pomegranate being non-climacteric fruit should be
picked when fully ripe. Harvesting of immature or over-mature fruits affects
quality. Its fruits become ready for picking 120–130 days after fruit set. The
calyx at the distal end of the fruit gets closed on maturity. Ripe fruits give
a distinct sound of grains cracking inside when slightly pressed from outside.
At maturity they turn to yellowish-red and get suppressed on sides. Fruit
colour is not sure guide to maturity. Plucking is done with hand. A grown-up,
well-managed tree gives 60–80 fruits annually, with a life span of 25–30 years.
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