role and deficiency symptoms of phosphorous in grape
DESCRIPTION
Role and deficiency symptoms of phosphorous in grape. 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. - PowerPoint PPT PresentationTRANSCRIPT
Role and deficiency symptoms of phosphorous in grape
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.
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.
Objective
After completing this lesson, you will be able to :
Learn the role and deficiency symptoms of phosphorous in grapevine.
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 helps with the transformation of solar energy into chemical energy; proper plant maturation; withstanding stress.
It effects rapid growth
It encourages blooming and root growth
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.
Role 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
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
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
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
Deficiency symptomsIn 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)
Poor bud initiation and fruit set may also be observed
Symptoms of phosphorus deficiency in a basal leaf of grapevine (Treeby et. al. 2004)
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.