nutrition role

1. CREDIT SEMINAR ON
ROLE OF NUTRIENTS IN CONTROLLING PLANT
DISEASES IN SUSTAINABLE AGRICULTURE

2. WHAT IS SUSTAINABLE AGRICULTURE ?
Management and utilization of agricultural resources in a
significant way.

3. In controlling plant diseases many factors act as source
of nutrient:
NutrientsLiming
Organic
amendments
Mulching Fertilization
pH
adjustment
Irrigation

4. NUTRIENTS TO CONTROL PLANT DISEASES
 The essential nutrients can affect the severity of a
disease in a positive or negative way.
 It has been recognized that nutrients can control
some of the most severe diseases.
 The disease cannot be totally eliminated but its
level of severity can only be changed.
 It is important with the correct nutrient management
to control diseases in order to obtain higher yield.

6. MECHANISMS OF DISEASE CONTROL WITH PLANT
NUTRIENTS
 Develops stronger cell walls and tissues in plants
which inhibit the effect of enzymes released by
bacteria responsible for dissolving the cell wall.
 Some nutrients reduces the feeding ability of some
sucking pests like aphid on plants which are known
vectors of viral pathogens.
 Nutrients can affect development of a disease by
affecting plant physiology or by affecting pathogens or
both of them.

7. CONTD..
 Nutrients like K promote the development of thicker
outer walls in epidermel cells that prevents disease
attack.

9. NUTRIENTS
Primary
macorynutrients
• Nitrogen (N)
• Phosphorus(P)
• Potassium(K)
Secondary
macronutrients
• Calcium(Ca)
• Sulfur(S)
• Magnesium(Mg)
Micronutrients
• Boron(B)
• Chlorine(Cl)
• Manganese(Mn)
• Iron(Fe)
• Zinc(Zn)
• Copper(Cu)
• Molybdenum(Mo)
• Nickel(Ni)

10. MACRONUTRIENTS….
The effect of N is quite variable depending on the type of
different pathogen like:-
 In case of obligate parasites, e.g. Puccinia graminis
and Erysiphe graminis, when there is high N supply
there is an increase in severity of the infection.
 While in case of facultative parasites, e.g. Alternaria,
Fusarium, Xanthomonas spp., high N supply decreases
the severity of the infection.
 The difference between these two parasites is due to
nutritional requirements.
Nitrogen

11. MACRONUTRIENTS…. CONTD…
 The form of N can affect the pH of the soil and also the
availability of other nutrients such as Mn.
 The levels of N can affect the phenolics content of plants,
which are precursors of lignin.

12. MACRONUTRIENTS…. CONTD…
Puccinia graminis Erysiphe graminis
Alternaria Fusarium

13. MACRONUTRIENTS…. CONTD…
Pathogen or diseases Low N High N
Obligate
parasites
Puccinia graminis decrease increase
Erysiphe gramminis decrease increase
Oidium lycopersicum decrease increase
Plasmodiophora
brassicae
decrease increase
Tobacco mosaic
virus
decrease increase
Facultative
parasites
Xanthomonas
vesicatoria
increase decrease
Alternaria solani increase decrease
Fusarium oxysporum increase decrease
Effect of N level on disease severity of several diseases
(Agronomy for Sustainable Development, 2008)

14. MACRONUTRIENTS…. CONTD…
 Phosphorus is an important element that can improve crop
health and severity of many diseases.
 P improves resistance and tolerance to diseases that can
reduce crop yield and quality.
 P has been shown to be most beneficial when it is applied
to control seedlings and fungal diseases where vigorous
root development permits plants to escape disease.
 The negative impact of root diseases in several crops may
be reduced by the application of P fertilizer.
Phosphorus

15. MACRONUTRIENTS…. CONTD…
 Phosphate fertilization of wheat can have a significant
effect and almost eliminate economic losses from pythium
root rot.
 In corn, P application can reduce root rot, specially when it
is grown on soils deficient in P.
 P application can reduce bacterial leaf blight in rice, downy
mildew, blue mold, brown stripes in sugarcane, blast in rice
etc.

16. Blue mold BLB in rice
Brown stripes in sugarcane Powdery mildew in sugarcane

17. MACRONUTRIENTS…. CONTD…
 K- deficient plants is highly susceptible to parasitic
diseases.
 K can reduce the intensity of several infectious diseases of
obligate and facultative parasites.
 K prevents disease attack by the promotion of
development of thicker outer wall in epidermal cells.
 Severity of Helminthosporium leaf blight can decrease by
application of K.
Potassium

18. MACRONUTRIENTS…. CONTD…
 K may promote the development of thicker outer walls in
epidermal cells, thus preventing disease attack.
 K reduces the incidence of various diseases such as
bacterial leaf blight, sheath blight, stem rot, sesamum leaf
spot in rice, black rust in wheat, bacterial leaf blight in
cotton, red rust in tea etc.

19. MACRONUTRIENTS…. CONTD…
Brown spot in rice Sheath blight in rice
Stem rot in rice

20. MACRONUTRIENTS…. CONTD…
Pathogen or diseases Low K High K
Puccinia graminae increase decrease
Xanthomonas oryzae increase decrease
Tobacco mosaic virus increase decrease
Alternaria solani increase decrease
Fusarium oxysporum increase decrease
Pyrenophora tritici-
repentis
increase decrease
Erisiphe graminis increase decrease
Effect of K level on disease severity of several diseases
Source: Agronomy for Sustainable Development 28(2008) pp-33-46

21. MACRONUTRIENTS…. CONTD…
 Ca is important for the stability and function of plant
membranes.
 Plant tissues low in Ca are also much more susceptible
than tissues with normal Ca levels to parasitic diseases
during storage.
 Application of Ca to the soil eliminates the occurrence of
the disease.
 Ca treatment of fruits before storage prevents losses both
from physiological disorder and fruit rotting.
Calcium

22. MACRONUTRIENTS…. CONTD…
 Ca confers resistance against Phythium, Sclerotinia,
Botrytis and Fusarium.
 Ca is believed to provide protection against Sclerotinia
sclerotiorum is by strengthening the cell wall.

23. MACRONUTRIENTS…. CONTD…
Pathogen Host/Disease Factor Effect
P. infestans Potato late blight
K Decrease
High K
High N
Increase
P. capsici Pepper blight K Decrease
P. drechsleri Pigeon pea blight High K
Low N
Decrease
P. parasitica Citrus gummosis High K
Low Ca
Increase
Source: Paul, St. (1983). Phytophthora, its biology, taxonomy, ecology and
pathology. p-191
Effect of K, N and Ca on severity of Phytophthora disease

24. MACRONUTRIENTS…. CONTD…
 There are very fewer reports of direct effects of Mg on plant
diseases.
 Fusarium wilt pathogens tend to be less severe when
adequate Mg is available.
Magnesium

25. MACRONUTRIENTS…. CONTD…
 Sulfur has direct and indirect effects on disease through:
- plant growth and resistance
- reduced pathogen virulence or survival
- changing the abiotic environment
- changes in the biological environment
 Sulfur can be used to balance other nutrients and make
the environment less favorable for the pathogen.
Sulfur

26. MACRONUTRIENTS…. CONTD…
 Sulfur compounds in root exudates, and metabolites from
residue decomposition affect pathogen virulence, plant
resistance, and bilogical control,
 The incidence of powdery mildew and stem rust is
reduced under adequate supply of S to the wheat crop.
 S can reduce the severity of potato scab.

27. MACRONUTRIENTS…. CONTD…
Host plant Diseases Effect of S
Cotton, tomato Fusarium wilt, Verticillium
wilt
Decrease
Crucifers Club root Decrease
Grape Powdery mildew, Downy
mildew
Decrease
Maize Leaf blight, Stewart wilt Decrease
Potato Common scab, late blight,
Stem canker
Decrease
Soybean Rhizoctonia root rot Decrease
Sugarbeet Ramularia leaf spot Decrease
Wheat Powdery mildew, Sharp
eye-spot
Decrease
Source: Huber, Don M. (2015). The role of sulfur in nutrient-disease
interaction

28. COMMERCIAL FORMULATION
Urea DAP MOP
Magnesium Calcium Sulfur

29. MICRONUTRIENTS…
 Manganese fertilization control pathogenic diseases such
as powdery mildew, downy mildew etc.
 Mn inhibits the induction of aminopeptidase, an enzyme
which supplies essential amino acids for fungal growth and
pectin methylesterase, a fungal enzyme that degrades host
cell walls.
 Mn soil applications reduce common scab of potato,
Fusarium wilt in cotton.
Manganese

30. MICRONUTRIENTS… CONTD…
Common scab in potato Fusarium wilt in cotton

31. MICRONUTRIENTS… CONTD…
 Application of Zn reduced disease severity, toxic effect on
pathogen directly and not through the plant’s metabolism.
 Diseases, control like root rot, wilt, sheath blight, cotton
wilt, foot rot in soybean, and powdery mildew in pea.
Zinc

32. MICRONUTRIENTS… CONTD…
 Fe is immobile in soil and plants and the most soluble iron
is present as iron siderophores.
 These siderophores are important as agents of protection
from bacteria.
 These siderophores can suppress germination of
chlamydospores of Fusarium oxysporum f.sp. cucumerinum
in vitro.
 The production of siderophores and antagonism for Fe is
not only the mechanism to limit the growth of parasitic
fungus.
Iron

33. MICRONUTRIENTS… CONTD…
 B has a direct function in cell wall structure and stability and
has a beneficial effect on reducing disease severity.
 The function that B has in reducing disease susceptibility
could be because of: (1) cell wall structure (2) cell
membrane permeability, stability or function
3) metabolism of phenolics or lignin.
 B promotes root growth that helps plant to restrict fungal
hyphae from movement through the cell wall and acts as
barrier to infection of patogens.
Boron

34. MICRONUTRIENTS… CONTD…
 B reduce diseases caused by Plasmodiophora brassicae in
crucifers, Fusarium solani in bean, Verticillium albo-atrum in
tomato and cotton, tobacco mosaic virus in bean, tomato
yellow leaf curl virus in tomato, G. graminis and Blumeria
graminis in wheat.

35. MICRONUTRIENTS… CONTD…
 Copper fertilization helps in management of diseases like
powdery mildew and leaf rust in wheat, ergot in rye and
barley, wilt in tomato, and common scab in potato.
Copper

36. MICRONUTRIENTS… CONTD…
 Cl shows synergistic effect with K and form KCl which is quite
effective in reducing the severity of plant diseases.
 Thomason et al.(2001) reported inconsistent results on the
severity of take-all diseases with Cl application, even following
the application of lime where increased soil pH can increase
disease severity.
 Cl control number of diseases such as stalk rot in corn, stripe rust
in wheat, northern corn leaf blight and downy mildew of millet,
and septoria in wheat
Chlorine

37. MICRONUTRIENTS… CONTD…
 Si creates a physical barrier in cuticle of plant leaves and
sheaths and control blast and brown spot in rice.
 Si reduces the intensity of multiple plant diseases caused
by biotrophic, hemibiotrophic, and necrotrophic pathogens
in many crops of great economic importance.
Silicon
Relationship of brown spot severity and neck blast incidence to rates of
calcium silicate

38. MICRONUTRIENTS… CONTD…
Hosts Diseases Pathogens Effects* References
Monocots
Rice Leaf and panicle blast Pyricularia oryzae + Sun et al.(2010), Santosh et
al.(2011), Cacique et al.(2012),
Junior and Bolaldo(2013)
Banana Black Sigatoka Mycospharella fijiensis + Kablan et al. (2012)
Barley
Black point Alternaria sp. + Kunoh and Ishizaki(1975)
Powdery mildew Blumeria graminis. f
sp. hordei
+ Wiese et al. (2005)
Corn Corn smut Ustilago maydis + Tamini and Hunter (1970)
Pearl millet Downey mildew Sclerospora
graminicola
+ Deepak et al.(2008)
Wheat
Leaf rust Puccinia tritici × Wordell Filho et al. (2013)
Rusts Puccinia spp. / Rodgers-Gray and Shaw
(2004)
Powdery mildew Blumeria graminis f.
sp. graminis
+ Belanger et al. (2003), Guevel
et al. (2007), Curtis et al.
(2012)
Effect of silicon on some host-pathogen interactions(monocot crops)
*Silicon can decrease(+), increase(×), or has no effect (/) on disease intensity
Source: Rodrigues, F. A., L. E. Datnoff .(2015). Silicon and plant diseases. pp- 68-73

39. MICRONUTRIENTS… CONTD…
Hosts Diseases Pathogens Effects* References
Dicots
Bean Anthracnose Collectotrichum
lindermathianum
+ Moraes et al.(2006,
2009), Polanco et al.
(2012,2014)
Coffee Leaf rust Hemileia
vastratrix
+ Pereira et al.(2009),
Carre-Missio et al.
(2012,2014)
Potato Late blight Phytophthora
infestans
/ Duarte et al.(2008),
Soratto et al.(2012)
Rose Powdery mildew Sphaerotheca
pannosa
+ Shetty et al.(2012)
Tobacco TMV Tobacco mosaic
virus
/ Zellner et al.(2011)
Tomato Late blight Phytophthora
infestans
/ Duarte et al.(2007)
Effects of silicon on some host-pathogen interactions(dicot crops)
*Silicon can decrease(+), or has no effect(/)
(Rodrigues and Datnoff, 2015)

40. COMMERCIAL FORMULATION
SiliconZinc Copper
Maganese Boron Iron

41. CONCLUSION
 In sustainable agriculture, balanced nutrition is an essential
component of any integrative crop protection program
because in most cases it is more cost effective and also
environmental friendly to control plant diseases with the
adequate amount of nutrients.
 Nutrients can reduce disease to an acceptable level, or at
least to a level at which further control by other cultural
practices are more successful.
 Nutrient application had a much greater effect on reducing
disease when the plants were at deficiency levels.

42.  Supraoptimal rates of nutrients can also decrease the
disease incedence.
 The addition of nutrients or application of fertilizers
decreased the incidence of disease in crop plants.