Integrated nutrient management in mango

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Role and deficiency symptoms of phosphorous in
grape
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Role and deficiency symptoms of phosphorous in
grape


Introduction
Soil phosphorous is divided into two classes,
organic and inorganic. The concentration of
phosphorous in soil is very low. Since P is
associated with various types of plant
metabolism, P deficiency leads to metabolic
disorders.

To insure proper growth and yield of grapevines,
it is important to supply P exogenously. For
correcting the deficiency of P, it is important
to know the deficiency symptoms of P in grapevine.
Hence, it is important to apply phosphorous
judiciously by both organic and inorganic source
as per the requirement of P to get higher yield
without affecting soil health.
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Role and deficiency symptoms of phosphorous in
grape

Objective

• After completing this lesson, you will be able to
  
• Learn the role and deficiency symptoms of
  phosphorous in grapevine.

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Role and deficiency symptoms of phosphorous in
grape

Role of phosphorous in grape
Phosphorus (P) is an essential part of the
process of photosynthesis.

It involved in the formation of all oils, sugars,
starches, etc.
It effects rapid growth
It encourages blooming and root growth
It helps with the transformation of solar energy
into chemical energy proper plant maturation
withstanding stress.
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Role and deficiency symptoms of phosphorous in
grape

Role of phosphorous in grape
Phosphorus (P) is involved in the transfer of
energy within plant cells that facilitate
metabolism constituent of the fatty portion of
cell membranes and of compounds involved.

It also helps in assimilation and metabolism of
carbohydrates
It constitutes approximately 0.1 to 0.3 of dry
matter of the vine, equivalent to 1.3 lbs per ton
of grapes.
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Role and deficiency symptoms of phosphorous in
grape

Deficiency symptoms
Symptoms of P deficiency first seen on older
leaves and the margin of the leaves turned golden
yellow to light brown

Central parts of leaves remained normal green
with chlorotic areas becoming necrotic late in
the season
In extreme deficiency whole leaf blade dried up
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Role and deficiency symptoms of phosphorous in
grape

Deficiency symptoms

The higher level of phosphorus in shoots of
Dashehari found favourable for flower-bud
formation.
Development of necrotic areas on the margins of
leaves which become chlorotic and sheds heavily.
Phosphorous deficiency caused fall of bloom and
basal leaves turn yellow
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Role and deficiency symptoms of phosphorous in
grape

Deficiency symptoms

Red dots on basal leaves are appeared especially
on the mid or terminal lobes due to phosphorous
deficiency
At later stage, red dots line up at right angles
to the secondary veins and form dark red bars
Alignment of red bars at right angles to the
veins is a unique and most distinctive symptoms
of P deficiency
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Role and deficiency symptoms of phosphorous in
grape

Deficiency symptoms

Reduced growth, dull green leaves, premature
defoliation and pre mature berry ripening also
caused by P deficiency
Larger dark green leaves and violet-red
anthocynin pigments on the petiole is also seen
due to P deficiency
Deficiency of phosphorus in vines can result in
reduced vine vigor and yellowing of the
interveinal area of basal leaves
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Role and deficiency symptoms of phosphorous in
grape

Deficiency symptoms
In extreme cases, some red discoloration of the
interveinal area of basal leaves may be observed,
followed by early defoliation of these leave

These symptoms may be confused with leaf roll
virus but phosphorus symptoms occur earlier in
the growing season (flowering)
Symptoms of phosphorus deficiency in a basal leaf
of grapevine (Treeby et. al. 2004)
Poor bud initiation and fruit set may also be
observed
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Toxicity of Phosphorus
Role and deficiency symptoms of phosphorous in
grape

Excessive phosphorus has not been shown to be a
direct problem for grapevines however it may
limit the uptake of other essential elements,
such as zinc.