Transcript Role and Deficiency / toxicity Symptoms of Micro Nutrients in Banana

Role and deficiency/toxicity
symptoms of Micronutrients
in Banana
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Introduction
Micronutrient or trace elements are essential
for plant growth but it is needed in very small
quantities in the plant system.
The micro nutrient deficiency symptoms
are first expressed in younger leaves than
the older leaves.
The
micronutrients
are
Zinc
(Zn),
Molybdenum (Mo) Boron (Bo) Manganese
(Mn), Copper (Cu), Iron (Fe).
They are usually found in association
with larger molecules such as
cytochromes, chlorophyll, and proteins
(usually enzymes).
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Micro Nutrients
Boron
Iron
Manganese
Zinc
Copper
Molybdenum
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Role of Zinc
Activator of enzymes viz., Enolase,
Yeast
aldolase,
Oxalaetic
decarboxylase , Carbonic anhydrase,
Alcohol dehydrogense
Maintenance of auxin in an active
state
Metabolic pathway from tryptophan
to auxin via tryptamine
Responsible for proper functioning of
Chloroplasts.
Involved
in
protein
mediated through RNA
synthesis
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Deficiency Symptoms of Zinc
•
Bunchy foliage
•
•
•
Stunted growth
Leaf deformity
Increase in leaf length to breadth
ratioLeaves become either entirely
white
•
•
White towards the base
Chlorotic
transverse
stripes
alternating with greener bands
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Deficiency Symptoms of Zinc

Chlorotic parts show numerous small, oblong,
lighter patches

Severe deficiency viz.,


Fruit development is slow

Shorter


Thinner
Fingers twisted
Lighter green in color
Recommendation
Spraying Zinc Sulphate (0.5%) on the leaves is recommended.
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Role of Copper

Activator of several enzymes viz.,


tyrosinase,


ascorbic acid oxidase,
laccase,
butryl Co-A dehydrogenase

Light reaction in plants



Protein synthesis
Carbohydrate Metabolism
Absorbed by plants as the cupric ion (Cu++) and as a chelate both
by leaves and roots
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Deficiency Symptoms of Copper
•
•
Overall drooping appearance
Shortened intervals between leaf petioles
emerging from the pseudo stem.
•
The leaves droop and resemble like an
umbrella
•
Reduction in Leaf size
•
•
LB ratio reduced to 2.1 to 2.2
Susceptible to fungal and viral infections
Toxicity Symptoms
•
Root growth inhibited
Recommendation
Spraying Copper Sulphate (0.5%) on the leaves is recommended.
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Deficiency Symptoms of Iron
Iron
deficiency
has
been
recorded in alkaline soils and
is identified
by interveinal
chlorosis of young leaves.
Recommendation
Soil application of FeSO4 5/g/ha
or foliar spray of 0.5% FeSO4 at
weekly
intervals.
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Role of Manganese
•
•
•
Essential in respiration and N metabolism in plants
A relatively immobile element in plant
Antagonistic to Fe and excessive feeding leads to Fe deficiency
•
Activation of enzymes like



arginase


yeast phosphatase
cystcine desulfhydrase,
deoxyribose nuclease
Specific activator of prolidase

glutamyl transferase
•
Prominent component of chloroplasts and particularly involved in Hill reaction
of photosynthesis
•
Absorbed by plants as manganese ion (Mn2++ ) and as a chelate of EDTA
through roots as well as leaves
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Deficiency Symptoms of Manganese
Interveinal chlorosis in the middle of the sub
terminal
leaves
indicate
manganese
deficiency.
In moderate and acute stages of manganese
deficiency the dark green areas in the leaves
become dull green and the light green areas
persist throughout the life of the leaves
In severe cases, the light green areas often
become grey or even whitish, the foliage
becomes thin and shoots die back
Recommendation
Spraying Manganese Sulphate (0.5 %) on the leaves is recommended
After 14 weeks the disorder was cured.
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Role of Molybdenum
•
•
•
•
Essential in N Metabolism
Enzyme systems of symbiotic Nitrogen
fixation in legumes and non-legumes Protein synthesis
Acts
as
an
activator
of
dehydrogenases
phosphatases
• Activator of nitrate reductase and xanthene oxidase
and
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Deficiency Symptoms Molybdenum
• Lower levels of sugars and ascorbic acid
• Very low aminoacids
• Restricted vegetative growth and their leaves become pale
and wither
• Flower formation restricted. Appears first in the middle and
older leaves
• Leaves appear yellowish green
• Rolling of leaf margins
• Leaves become small and covered with necrotic spots
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Role of Boron
•
•
Involved in carbohydrate metabolism
Facilitates the movement of sugars by forming permeable
boron-sugar complex.
•
•
•
•
Regulates water relations
calcium in soluble form within the plant
Acts as a regulator of K ratio
Regulatory role in

Switching the degradation of glucose to either
glycolysis

Pentose shunt pathway
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Role of Boron
•
Implicated in



•
•
N metabolism
Photosynthesis
Cellular differentiation and development
Translocated from older to meristematic tissues is not ready
Absorbed by plants in one or more of its ionic forms



B4O7

BO-3
H2BO3
HBO-3
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Deficiency Symptoms of Boron
• Stunted growth of plants
• Newly emerging leaves found to be
malformed
with
development
incomplete
laminar
• Chlorotic
streaks
are
aligned
perpendicular to the veins on the leaf
lamina
• Severe
interveinal
chlorosis
and
incomplete leaf formationRoot and flower
formation are inhibited
Recommendation
Application of Borax Salt (25 g/ Plant) in the soil around the root zone of
the plant is recommended.
Role and deficiency/toxicity symptoms of Micronutrients in Banana
Let Us Sum Up
Micronutrients are required in very small quantities by the plant
for their functions.
Since they are involved in various enzymatic activities ,their
deficiency causes in various malfunctioning of the plant
activities.
To manage these micro nutrient deficiencies spraying of
suitable chemicals at recommended levels by foliar application
will alleviate the deficiency.