irrigation scheduling and techniques in grapes
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IRRIGATION SCHEDULING AND TECHNIQUES IN GRAPES. Next. End. INTRODUCTION. Irrigation. Water supply should be ensured in vineyards during period of active growth and berry development stages. Irrigation should be given to field capacity. - PowerPoint PPT PresentationTRANSCRIPT
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Water supply should be ensured in vineyards during period of active
growth and berry development stages. Irrigation should be given to
field capacity.
During establishment period of vines after planting, frequent
irrigation during dry months may be required. Watering immediately
after pruning and fertilizer application should be done without fail.
Irrigation
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Irrigation at an interval of 5-7 days during initial berry development
stage till they become pea size and at 10 days interval till maturity is
better for good yields.
Watering should be withheld from 25-30 days prior to harvesting to
ensure quality of produce.
Quality of irrigation water is also important.
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Excess salt content in irrigation water, with EC
value of more than one causes injury to vines.
Irrigate vines immediately after planting. Vine water use is very low in
the first 6 to 8 weeks, but the vines have a small root system that
should be kept moist.
Initially vine growth (including root growth) is supported by stored
carbohydrates in the cutting/rootling.
Phosphoric acid and dry potassic fertilizer such as sulphate of potash
can be used as sources of P20S and K20 for application through irrigation
systems.
Numerous formulations containing two or more nutrients are available
for fertigation. About 30% saving in quantity of fertilizers can be achieved
through this technique.
Establishment phase
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Application of fertilizers through irrigation system, fertigation, has
been tried in grapes also.
Drip irrigation system is ideal for fertigation and only soluble salts
are applied through irrigation system to prevent clogging of
emitters.
Urea is widely used for fertigation since it readily dissolves in
water. Improved yields by applying 300 kg urea/ha for 60 days
after October pruning at 5 kg/ha/ day.
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The soil should be kept moist to promote further root growth. If
the soil becomes too wet, root growth will be inhibited. In most soil
types this means applying small amounts of water daily for the first
few weeks then less often.
To ensure the moisture of the soil is at an optimum install soil
moisture monitoring devices (e.g. tensiometers). Maintain the soil
moisture tension in the vines root zone between 10 and 60
centibars.
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• The aim is to maximise vine growth in years 1 to 3. Maintaining moist
soil throughout the growing season will help to achieve this.
• Soil moisture can be maintained by adjusting irrigation according to
soil moisture readings (e.g. tensiometers or gypsum blocks).
• Soil moisture should be maintained between 10 and 60 centibars.
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Maintaining soils in the readily available moisture range will maximise
yield throughout the growth cycle of the vines.
Irrigation techniques such as RDI and PRD can also be used to
manage vine growth and to manipulate fruit quality and yield.
Grape is a shallow feeder. Light and frequent watering is better for
grapes.
Water requirement of grape are very high during berry growth.
This period coinciding with hot and dry weather, more water is required
at this stage.
Least water is required during fruit-bud formation. This period if
coincides with cloudy weather and rains, watering are totally to be
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Currently due to the shortage of water, grapes are irrigated through drips.
The number of drippers/vine and their placement are very crucial in drip
irrigation. The active feeder root zone is to be wetted by the water
discharged through the emitters.
Reduced irrigation during ripening, i.e. (one month prior to
harvesting) improve the quality of grapes and hastens ripening. Too
much stress during ripening can also increase the berry drop at and after
harvesting.
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Since the wetted pattern is more horizontal than vertical in clay soils
but more vertical than horizontal in sandy soils, more emitters with
low discharge rate for longer duration are advisable to get good
results with drip irrigation in sandy soils.
Inadequate wetting of root zone reduces shoot vigour and
weakens the vines. Gradually they develop deadwood and go
barren 7-8 years after planting.
The quantity of water to let through drip irrigation daily depends
not only on the stage of growth of the vine but also the evapo-
transpiration in a vineyard.
Putting these two factors together the water requirement of
grapes through drips is given in Table3.
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Stage of growth Water required / ha
(litres/day)
1-40 days after summer pruning 48,000-60,000
41-100 days after summer pruning 24,000-32,000
101 days after summer pruning to
winter pruning
15,000-20,000
1-45 days after winter pruning 20,000-24,000
46-75 days after winter pruning 16,000-20,000
76-100 days after winter pruning 48,000-60,000
111 days after winter pruning until
harvesting
36,000-48,000
After harvesting untill summer pruning 20,000-24,000
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Grape is sensitive to chlorides and total salts content in irrigation
water.
Water with electrical conductivity of less than 1mmhos/cm, chlorides
less than 4m.e/litre, sodium adsorption ratio less than 8.0, residual
sodium carbonate less than 1.25 m.e/litre and boron less than 1.0
mg/kg is considered safe for irrigation grapes.
Raising a bund of loose soil to a height of 1’ along the vine rows
and mulching the soil around the drip zone by sugarcane trash or
paddy straw can conserve the soil moisture and save irrigation
water.
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1. Water saving to the extent of 60 % as compared to traditional surface
irrigation method
2. High water application efficiency
3. Increase in the yield to the extent of 25 - 30 % over traditional irrigation
methods.
4. Use of water soluble fertilizer, very high FUE with fertilizer saving to the
extent of 25 to 30% Use of saline water is possible
5. Reducing inter-culturing and weeding cost
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6. Excellent soil health and maximum soil microbiological activities
Saving in labour cost, due to atomization
7. Excellent and cost effective for horticultural crops - widely spaced,
low cost and long duration crop.
8. Adoptable for undulating topography, variable soil types and all
crops
9. Adoptable for undulating topography, variable soil types and all
crops.
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1. High initial cost due to solid system
2. Skilled man-power is required for design, operation and
maintenance
3. Availability of electricity as system is to operate daily or alternate
day deposits
4. The problem of clogging of emitters due to physical impurities,
chemical and biological residues of bacteria and algae
5. Periodical maintenance such as cleaning of filters, flushing of piping
network and pressure regulation in the system
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6. Treatment of back water flush system, (Sand filter cleaning),
acidification (Chemical clogging) and chlorination removal of algae
and bacteria are tedious and time consuming .
7. Breaking of lateral pipes due to cultural operation, rats and other
animal troubles
In spite of the above limitations and some problems the
micro-irrigation system has proved to be the best system
amongst all irrigation methods.
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