Myself Sorokhaibam Romio Singh,Now uploadindg one slide content regarding role of nutrients in controlling diseases developement in plants that i had given during my credit seminar programme at sasrd medziphema nagaland university. if any mistake present in my slide, kindly cooperate me to make correction on it. Thanku so much

1. Role of Nutrients in controlling
Disease development in Plants
Presented by
Sorokhaibam Romio Singh
M.Sc.Plant Pathology 4th sem.2020-22
Roll no .M-1399/20

2. KEY POINTS:
• Introduction
• Soil nutrients: Macro and Micronutrients
• Role and Deficiency Symptoms.
• Effect on severity of Diseases
• Relationship between cations and disease
severity of crops.
• Important micronutrients functions.
• Conclusion

3. INTRODUCTION
• Nutrients are important for growth and development of plants and also
microorganism and they are important factors in diseases control (Agrios
2005).All the essential nutrients can affect disease severity(Huber & Graham
1999).
• However,there is no general rule, as a particular nutrients can decrease the
severity of a disease but can also increase the severity of the disease
incidence of other disease or have a completely opposite effect in a different
environment(Maschner1995:Graham&webb1991:Huber1980).
• Despite the fact that importance of nutrients in disease control has been
recognized for some of the most severe diseases, the correct management of
nutrients in order to control disease in plants has received little attention
(Huber & Graham 1999)

4. SOIL NUTRIENTS AND IT’S ROLE
Macro vs Micro Nutrients
Macronutrients are required by the plants in
relatively large amount
Micronutrients are required only in small
amounts: minor or trace elements.

5. Macronutrients
Non mineral elements:
carbon(C),hydrogen(H), oxygen(o)
Primary nutrients:
Nitrogen (N),Phosphorous(P),potassium(k)
Secondary Nutrients:
calcium (ca),magnesium(mg),sulfur (s)

6. Micronutrients
• Iron (Fe)
• Copper(Cu)
• Zinc(Zn)
• Boron(B)
• Molybdenum (Mo)
• Manganese(Mn)
• Clorine(Cl)

7. Functions of Nitrogen
Promotes growth of leaves and stem
Gives dark Colour and improves quality of
foliage
Necessary to develop cell protien and
Chlorophyll

8. Material Supply Nitrogen

9. Deficiency Symptom of Nitrogen:
Sick, yellow-green color
Short stems, small leaves ,pale color leaves
and flowers
Slow and dwarf plant growth.

10. Nitrogen Deficiency

11. Functions of Phosphorous
Stimulates early formation and growth of
roots
Provides for fast and vigorous growth and
speeds maturity
Stimulates flowering and seed development
Necessary for the enzyme action of many
plant process.

12. Material Supplying Phosphorous

13. Phosphorous Deficiency Symptom
Decrease in growth
Slow maturity
 Older leaves are purplish color

14. Phosphorous Deficiency
Deformation of fruits and slow
maturity

15. Function of potassium
Used to form Carbohydrate and protiens
Formation and transfer of starch ,sugar and
oils.
Increase Disease resistance,vigour and
hardiness.

16. Material supplying potassium

17. Potassium deficiency
Mottled, spotted, streaked or curled leaves
Scorched,burned,dead leaf tips and margins.

18. Potassium Deficiency

19. Effect of k, N and Ca on severity of
Phytopthora Diseases
Pathogen Host/Diseases factor Effect
P.infestans Potato late Blight K
High k
High N
Decrease
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
Phytophthora,its Biology ,taxonomy, ecology and pathology,1983,APS press,st.paul,MN page
191.

20. Relationship Between cation content and severity of
infection with Botrytis Cinerea Pars. in Lettuce.
K Ca Mg Infection with
Botrytis
14.4 10.6 3.2 4
23.8 5.4 4.1 7
34.2 2.2 4.7 13
48.9 1.8 4.8 15
Cation content (mg/g dry wt.)
Infection index: 0-5 slight infection
6-10 moderate infection
11-15 severe infection
Based on krauss (1971), 1998, “ Mineral Nutrition of Higher plants 2nd Horst
Marschner.p.447

21. Tentative summary of the effect of Nitrogen
and Potassium level on the severity of Diseases
caused by parasites.
Pathogen and Diseases
Obligate parasites
Nitrogen level
low High
Puccinia spp (rusts) + +++
Erysiphe graminis (powdery
mildew)
+ +++
Facultative parasites
Alternaria spp.(leaf spots) +++ +
Fusarium oxysporum(wilts and rots) +++ +
Xanthomonas spp.(spots and wilts) +++ +

22. Tentative summary of the Effect of Nitrogen and
Potassium level on the severity of Diseases caused by
parasites (continued…)
Pathogen and Diseases Potassium level
Obligate parasite Low High
Puccinia spp.(rust) ++++ +
Erysiphe graminis (powdery
mildew)
++++ +
Facultative parasites
Alternaria spp.(leaf spots) ++++ +
Fusarium oxysporum (wilts and
rots)
++++ +
Xathomonas spp.(spots and wilts) ++++ +

23. Fig:8.1 Effect of potassium supply on grain yield of wetland rice and
incidence of stem-rot( Helminthosporium sigmoideum). Basal dressing of
nitrogen and phosphorus constant at 120 and
60 kg ha−1, respectively (Adopted from Ismunadji 1976

24. Fig:8.2. Mechanism of K in disease resistance in host plant –
Adopted from Wang-et-al-2013

25. Fig: 8.2.Effect of K level on disease severity of
several disease

26. Copper – Cu2+
 Increase cuticle thickness
 Cuticle : a barrier to infection
 Necessary for Polyphenoloxidase activity
 Polyphenoloxidase system produces some phytoalexins and other
anti-pathogenic molecule.
 Phyto alexins- antimicrobial compounds produced by plants in
response to a host -parasite interaction.
Dieback and gumming disease in citrus

27. Boron- B
 Increases the uptake of Cation (blevins,Schon, v.of Missouri)
 K, Ca and Cu are cations that are vital for plant resistance to
disease.
 Involved in the metabolism of phenolics.
 Phenolics include phytoalexins and other molecules that are
toxic to plant pathogen.
Necrotic pith and hollow curd formation

28. Manganese- Mn++
 Involved in the production of lignin
 Lignin is the principal component of wood and very difficult
to degrade.
 Wheat with higher uptake of manganese has a higher content
of lignin and is more resistant to take all diseases.
 Mn2+ inhibits the enzyme pectin methyl-esterase
 Pectin methyl esterase is a fungal pathogen exo-enzyme for
degrading host cell walls.
Yellowing leaves top down

29. CONCLUSION
Nutrients can reduce disease to an
acceptable level ,or at least to a level at
which further control by other cultural
practices or conventional organic biocides are
more successful and less expensive.

30. THANK YOU ONE
AND All FOR YOUR
KIND ATTENTION