Onion Presentations

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IRRIGATION IN ONION

1. The onion has a superficial root system, therefore waterwill be supplied to the plant will be through the soil, from thearea closest to the plant.

2. Onion plants are more sensitive to water stress than othercrops and this is due to the inability of the onion leaves tobalance water shortages by changing its osmotic capacity.When there is a water shortage, the root system is damaged.The onions root system changes throughout the growing

period: it starts with a narrow base and progresses outwards,with the central roots to degenerate

For this reason, it is necessary for the water outlet to be closeto the root zone and spacing between drippers will be

according to the number of rows and width of beds.


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Fertilization:

Fertilizing through the water has an advantage when usingdrip irrigation. Nitrogen and phosphorous are essential at theoutset of growth, and fertigation enables them to be absorbed

and makes them more readily available, depending on the typeof fertilizer and soil.

The onion is one crop that requires NPK throughout thegrowing season, and it is necessary to continue fertilization up

to the full drooping of the onion.


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The growing period is divided into 4 parts:

1. Sowing to 3 leaves

2. 3-6 leaves3. 6 leaves to when it stops producing leaves

4. until up to 30% drooping

- up to

30% drooping

6 leaves

stopping leafproduction

3-6 leavesSowing 3

leaves

1.2 kg per ha.4-6 kg per ha3.3 kg per ha.2 kg per ha.N

0.25 kg per ha.0.4 kg per ha.0.4 kg per ha.0.4 kg perha.P2O5

1.5 kg per ha.3.5 kg per ha.2.2 kg per ha.2 kg per ha.K2O

Note: for a high yield 125-150 thousand plants are required.


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Irrigation Control:

The onion plant has a small root system, therefore theirrigation frequency is important.

The interval between irrigation application is every 1-2 days

from the stage of 6 leaves. During periods of high evaporationand high temperatures, it is advantageous to irrigate severaltimes a day.


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Plant Protection / Diseases:

Peronospora is a disease that causes the leaves to dehydrate.This disease spreads more rapidly in areas with high humidity.

Drip irrigation maintains a relatively low humidity during

irrigation, reduces spray applications and decreases the spreadof disease in infected areas.


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Collecting Laterals:

Subsurface drip: it is possible to cultivate the area preciselyand to grow an additional season.

Surface drip: laterals will be rewound after cutting, which

makes removal easier.


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Water Quantities:

Pan evaporation rate:

Full drooping to

harvest

Bulb producing up

to 30% drooping

6 leavesend of

leaf production

3-6 leaves

80%110%90%-100%70%-90%


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44 inch

Spacing between drippers 12-14

Locating deep 6-12

1 lateral between every couple


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68 inch

Spacing between drippers 12-14

Locating deep 6-12

1 lateral between every couple


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Ideal condition

Water to the root system

Water outlet by

the leafs

Wet soil close to the rootWater to the plant

Water entering to the soil


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6 rows 3 laterals, sandy soil


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4 rows 2 laterals


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Healthy canopy


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After rain, there is place for draining water


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Onion Presentations

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