2. To help in identifying physiological disorders it
important to know that:
Physiological disorders caused by the lack or excess
of something that supports life or something that
interferes with life.
Physiological disorders can affect plants in all stages
of their lives.
They occur with the absence of infectious agents
therefore cannot be transmitted.
Physiological disorders are serious in themselves but
Physiological disorders are deformities in the plants parts including
the economic parts caused by non-pathological agent such as poor
light, weather damage, irregular moisture supply or a lack of
nutrients and affect the functioning of the plant system.
3. 1. Due to deficiency of nutrient.
2. Due to excessive nutrient
3. Due to water deficiency
4. Due to low temperature
5. Due to poor ventilation
6. Due to deleterious effect of ethylene
7. Due to excessive exposure to sun rays
8. Due to multiple causes, etc.
4. Symptom:- Appearance of water soaked area.
Rapid desiccation .
Formation of sunken spot .
Grey or whitish patch.
Causes:- High sun rays.
Induction of sunscald damage at 40
0
C and above .
Control:- Protection from sun rays.
5. Symptom:- Yellowish and whitish patches
on tomato.
Causes:- Deficiency of potassium.
Excess nitrogen.
Control:- Application of potassic
fertilizer @ 20-25 kg/ha.
Imbalance of nitrogen and potassic nutrient in soil and water deficit at the
time of excess transpiration rate and collapse of parenchymatous cells of
the Pericarp.( Seaton and Gray,1936).
6. Symptom:- Flattened surface of fruit.
Fruit is hollow and light weight.
Causes:- Poor pollination.
Fluctuation in temp.
Water deficiency.
Control:- Frequent irrigation.
Spraying boric acid (10-15 ppm).
The affected fruits are light in weight, more or less hollow and angular with flat
sides. Sometimes, there is irregular external appearance (Rating et al., 1961)
Puffiness are poor fertilization and abortion of ovules, which take place under
adverse conditions particularly high or low temperature and low soil moisture.
(Palevitch and Kedar, 1963)
7. Symptom:- Cracks on the fruit
surface.
Causes:- Deficiency of boron.
Excessive moisture after
Water deficiency.
Control:- Application of boron
@15-20kg/ha.
Resistant variety “Jet
star”
The fruit cracking was a more severe problem with the widest
spacing (80 cm within the row, with the rows 1.8 m apart).
(Mullins and Straw, 1992)
This disorder generally occurred six to seven weeks after fruit set.
( Bakker 1988)
8. Symptom:- Golden colour flecks appear
on the fruit surface.
Cause:- Genetically.
Excess of ca oxalates.
Low k:ca ratio
Control:- Select resistant variety.
Walter is a variety with reduce incidence of gold
fleck(Burgis et al.,1977)
9. Symptom:- Fruit looks like
catface.
Causes:- Poor pollination.
Low temperature.
Control:- Select good variety.
Balanced nutrient.
The deformity is caused by something (internal & external) that
occurs during the formation of the flower that results in the fruit not
developing normally(Olson, 2004).
10. Symptom:- Water soaked spot.
Sunken and leathery.
Causes:- Calcium deficiency.
Irregular moisture
High temperature.
Control:- Foliar spray of 0.5%
calcium chloride
Influence of truss size since thinning increased the incidence of this disorder.
(Dekock et al.,1982)
Occurrences increases dramatically when calcium level in the soil system drop
below 0.08%.(Moretti et al., 2000)
11. Symptom : - Presence of a
irregular shaped
cavity in pith of
the tuber of potato .
Cause :- high nitrogen.
moisture imbalance.
Control : - balanced nutrition.
12. Symptom :- Irregular dry brown
spots on flesh of tuber.
Spots never found in
vascular region.
Causes :- Irregular irrigation.
Control :- Regular irrigation.
Internal brown spot of potato
13. Symptom:- Dark grey or inky black
discolouration occur.
Causes:- High temperature.
Inadequate supply of O2.
Control:- Balanced fertilizer and
irrigation.
Proper ventilation.
Black heart of potato
14. Symptom:- Development of green
pigment .
Cause:- Directly exposure to the
sunlight.
Control:- Cover the tubers with top.
16. Symptom:- tuber do not sprout
readily after planting .
Cause:- Delay and erratic crop
stand .
Control:- Tuber cutting, Thiourera
treatment.
17. Symptom :- Water soaked area on the curd
later on pinkish or rusty brown
surface.
Causes :- Boron deficiency.
Control :- Apply borax 10-15 kg/ha.
Boron deficiency can be overcome by applying borax or sodium borate @
20kg/ha.(Dutta,1999)
18. Symptom:- Very small curds or button.
Causes:- Early cultivar planted late.
Over-aged seedling.
Deficiency of nitrogen
Limited soil moisture.
Control:- Adequate supply of
nutrients.
Most of the cultivars were less susceptible to buttoning when
sown on 1st September as compared to 1st October and 1st
November. (Rashid et al., 1990).
19. Symptom:- Very small curds or button.
Causes:- Early cultivar planted late.
Over-aged seedling.
Deficiency of nitrogen
Limited soil moisture.
Control:- Adequate supply of
nutrients.
Most of the cultivars were less susceptible to buttoning when
sown on 1st September as compared to 1st October and 1st
November. (Rashid et al., 1990).
20. Symptom:- Reddish tan and
brown elongated pit like
spot.
Causes:- Ethylene.
Control:- Proper ethylene
concentration.
Russet spotting of
Cauliflower
21. Symptom:- Water soaked and
discoloured
tissues on hollow curd and
stem.
Causes:- Excessive of nitrogen.
Deficiency of boron.
Control:- Spraying Borax 0.1-0.3 %.
Optimum use of nitrogenous
Fertilizer.
Closer spacing.
The use of multiple plants per transplant plug reduces of
hollow stem.(Griffith and Carling,1991)
22. Symptom:- Plant becomes chlorotic and turn white.
Leaf cupped shape and leaflet do not
develop properly look as strap like.
Midribs develop which account whiptail.
Causes:- Deficiency of molybdenum.
Acidic soil.
Control:- Application of 2.5 kg/ha sodium
molybdate .
Liming in the soil.
on whiptail is studied by Blatt and Beusichem (1990).
Application of molybdenum 1.5 kg/ha accompanied by lime 3 t/ha
mitigated whiptail of cauliflower.(Kotur, 1994)
23. Symptom:- Light brown tissues.
later on dark brown or
black
Causes:- Ca deficiency.
High doses of nitrogen
and high humidity.
Control:- Grow resistant or
tolerant variety.
Four foliar sprays of calcium chloride at 2 g/litre alone or in
combination with CCC (120 ppm) reduced the appearance of tip
burn. (Maroto et al., 1996)
24. Symptom:- Green bracts grow out of
the curd.
Causes:- High temperature.
Application of excessive
nitrogen.
Control:- Selection of proper
varieties.
Leafiness, which is the result of development of bracteoles may
possibly be due to the partial reversion of curding to the vegetative
phase. (Fujime et al., 1996).
25. Symptom:- Premature initiation of floral
bud.
Causes:- Fluctuation in temperature.
Heavy nitrogen dressing.
Control:- Optimum use of nitrogenous
fertilizer.
The incidence of riceyness is positively correlated with the
temperature from 15 to 25 days after curd initiation (Grevsen et al.,
1994).
Pusa Deepali and Pusa Shubhra have been less susceptible
(Chatterjee et al.,1991)
26. Symptom :- Pink colouration on the
curd
Cause :- High light intensity
Control :- Protection from sun rays.
27. Symptom:- Burning of lateral margin of
inner
Leaves of mature head.
Causes:- Unfavourable climatic
condition.
Calcium deficiency.
Control:- Application of calcium
chloride @ 12 kg/ha. Good
management.
Iceberg cultivar Raider, Casino, Toronto, Ponderosa, King way
showed good tolerance of tip burn.(Farm Service Victoria, 2010).
Cos cultivar Verdi, Conatus and cosmic showed best tolerance
to tip burn.(Farm Service Victoria, 2010).
28. Symptom:- Tip burn of the young leaves.
Drying and blackening of
leaves.
Kill the entire heart.
Causes:- Calcium deficiency.
Control:- Application of calcium –
sulphate 25kg/ha.
Other associated factors with black heart are less vigorous
growth, varietal susceptibility, high temperature, high fertility
level and high soluble salt level. (Bible and Stiehl,1986)
29. Symptom:- Affected tissue collapse.
Stem become light
yellow and
form corky
layer.
Causes:- Boron deficiency.
Control:- Application of Borax 25
kg/ha.
Utah 10-8 is the most susceptible variety of celery whereas Utah
52-70 and summer Pascal are the most resistant to this
disorder.(Yamguchi et al., 1953)
30. Bolting :- Pre emergence of seed stalk prior to time of
their
formation.
Causes :- Low temperature after sudden rise.
Late transplanting of seedlings.
Poor supply of nitrogen
Control :- Adjust the time of transplanting
Resistant variety- Early Grano.
Supply recommended dose of nitrogen.
31. Symptom: Sprouted prior to time of their
planting.
Causes : Improper air circulation led to
moisture buildup
Control : Proper ventilation
32. Symptom : Single plant showing double bulbs.
Causes : Size of bulbs and planting time
Control : Adjust time of planting, optimum bulb
size
33. Symptom:- Sprouting in garlic at
maturity.
Causes:- Excessive soil moisture.
Excessive nitrogenous
fertilizer.
Control:- Balanced irrigation and
Application of N fertilizer.
Varietal difference, spacing, and early planting may sometimes
be the possible causes of sprouting (Mollejas and Mata,1986)
White cultivars are more susceptible to sprouting than
pink/purple varieties. (Pandey and Singh,1993)
34. Symptom:- Cavity spot appears on the
cortex.
Subtending epidermis collapse to form
Pitted lesions.
Causes:- Calcium deficiency.
Control:- Application of calcium
sulphate 25 kg/ha.
Higher Calcium concentration in the growing medium increases
the absorption and accumulation of Ca in plant and reduces the
incidence of cavity spot.( Maynard et al., 1961)
35. Symptom:- Deformed carrots can be
caused by a variety of problems and
may be forked, bumpy or otherwise
misshapen.
Causes:- Manure has not properly
decomposed,Variety problems, soil
hard pan, etc.
Control:- Proper tilth of soil, improved
variety.
36. Symptom:- Cracks on the
surface of root.
Causes:- High nitrogen doses.
Boron deficiency.
Irregular irrigation.
Control:- Balanced nitrogen.
Regular irrigation.
Borax 20-25 kg/ha.
Use of wider spacing, early sowing, longer growth duration and
genotype.
( Warne,1951; Dower and Jackson,1977.)
37. Symptom:- Hard or corky black
spot on the root.
Malformed leaves.
Cause:- Deficiency of boron.
Control:- Apply borax 15-20
kg/ha.
Detroit Dark Red variety of beet show comparatively less symptom
of B deficiency.(Vegetable Science,2008).
38. From above discussion climate change and global
warming increase the incidence of physiological
disorder and it also increase through changing in
soil health or nutrient status of soil.
Physiological disorders can affect plants in all
stages of their lives and it increase the incidence of
biotic disorder.
Good management practices and development of
resistant or tolerant variety to reduce the incidence
of physiological disorders.
