MINERAL NUTRITION

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MINERAL NUTRITION PLANT DISEASE PESTS
Resistant phenomena
1. Anatomy (eg. Thicker epidermal cells,
higher degree of lignification)
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2. Physiology Biochemistry
(Production of repelling substance
synthesis of toxins phytoalexins)
3. Escape from attack
(not synchronize development)
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General role of nutrient
Balanced nutrient supply which ensures
optimal plant growth is also considered
optimal for plant resistance.
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1. Fungal disease
1.1 Principle of infection

• Plant exudate promote spore germination on
  leaf root (air - soil borne)
• Exudate depend on cellular
• concentration membrane permeability

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• Sugar amino acid K deficient
• Amino acid amide N excessive
• Phenol accumulation N, B Cu deff.
• Ca2 inhibit function of proteolytic
• enzyme from fungi to dissolve middle
• lamella
• Si increase lignification of epidermal
  cell
• layer
• N K effect depend on type of parasite

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Ca
1) increase stability of membrane
Ca efflux of sugar from cytoplasm
apoplasm
more severe infection
2) Ca - pectate middle lamella stability
inhibit proteolytic enzyme of fungi
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2. Bacteria Viral disease
Leaf spot diseases
Bacteria
Soft rots
Vascular diseases
Leaf spot diseases infect through stomata
multiply in the intercellular space
K Ca deficient enhance infection
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Soft rots infect through wounds and produce
proteolytic enzyme

• Wound cork formation inhibit
• infection increase formation when
• K sufficient
• B deficient causes cracking
• Ca inhibit proteolytic enzyme

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Vascular disease plug vessel of xylem then
causes wilt bacterial wilt
Viral diseases

• need amino acid nucleotides
• excessive N, P K reduce severity of
• N deficient in plant due to nutrient
• competition

between virus plant cells
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3. Soilborne Fungal Bacterial Diseases
Protection

• Chemical barriers (Polyphenol)
• Physical barriers (Sillicon in endodermis)
• pH adjustment and fungal growth
• Mn, Ca application
• NH4 NO3 - base fertilizer pH

• Ammonia toxic to Fusarium
• Nitrite (NO2) toxic to Pythium
• Phytophthora

The End