Pp10

• Non parasitic causes of plant diseases

  • Light
  • Temperature
  • Moisture
  • Air
  • Nutrient
• Inadequacy or excess of environmental factors leads to changes in the normal functioning of plants and disease occurs
• Non parasitic agents of disease are non-living and not spread from healthy to diseased plants
• Non-infectious diseases are recognized by their symptoms
• Knowledge of soil conditions, temperature ranges, weather, and other environmental factors are necessary for correct diagnosis of non-infectious diseases
• Proper diagnosis is difficult when multiple environmental factors are involved in disease development
• Common non-parasitic causes of diseases in plants

  • Excessively low temperature
  • Temperatures that are too high
  • Lack of oxygen
  • Too much or too little light
  • Adverse meteorological conditions
  • Air pollutants
  • Mineral deficiencies
  • Mineral excessive
  • Unfavorable soil pH
  • Excessive pesticide levels
  • Improper agricultural practices
  • Lack or excess of soil moisture
  • Naturally occurring toxic chemicals
• Disease caused by lack of oxygen

  The black Heart disease of potato occurs when oxygen is insufficient, leading to suffocation and blackening of tissues, common in waterlogged soils and poorly aerated storage areas
• Diseases caused by adverse physical factors

  1. Diseases caused by low temperatures

  2. Disease caused by lack of oxygen
• Diseases caused by too much or too little light

  Reduced light intensity leads to etiolated plants, increased susceptibility to infection by non-obligate parasites, decreased susceptibility to obligately parasitic fungi, increased susceptibility to virus infection
• Diseases caused by adverse meteorological conditions

  Strong winds and heavy rains can cause various disorders, leaves may rip, turn water-soaked, predisposed to bacterial and fungal infections, entire fields of crop may be blown down and killed
• Lightning injury is common on trees after a lightning strike, appearing as black, burned
• PANs concentration of 0.01 ppm for six hours may be enough to cause injury to plants
• Diseases caused by mineral deficiencies

  1. Nitrogen Deficiency = chlorotic leaves, dwarfing, premature leaf fall, poor seed and poor production

  2. Phosphorus Deficiency = subnormal roots, erect leaves, necrotic, reddish or purplish tints

  3. Potassium Deficiency = chlorotic tips on leaves, scorched tips and margin, bronzing, marginal scorching, reddish brown and dying
• Key components for plant growth

  • ds
  • sugar
  • phosphates
  • nucleic acids
• Plants affected by Potassium Deficiency

  • Banana
  • Corn
• Potassium Deficiency symptoms
• Potassium

  Involved in photosynthesis and transpiration
• Plants affected by Magnesium Deficiency

  • Banana
  • Corn
• Magnesium Deficiency symptoms
• Magnesium

  Essential component of chlorophyll
• Plants affected by Iron Deficiency

  • Banana
  • Corn
• Iron Deficiency symptoms
• Iron

  Constituent of chromosomes, involved in transpiration, heme enzymes, and chlorophyll synthesis
• Plants affected by Manganese Deficiency

  • Banana
  • Corn
• Manganese Deficiency symptoms
• Manganese

  Enzyme activator of photosynthesis, carbohydrate metabolism, and nitrogen metabolism
• Plants affected by Sulfur Deficiency

  • Banana
  • Corn
• Sulfur Deficiency symptoms
• Sulfur

  Component of amino acids, cysteine, cysteine, methionine, and vitamins like biotin and thiamine
• Plants affected by Boron Deficiency

  • Banana
  • Rice
• Boron Deficiency symptoms
• Boron

  Involved in sugar transport and carbohydrate metabolism
• Plants affected by Copper Deficiency

  • Rice
  • Corn
• Copper Deficiency symptoms
• Copper

  Involved in photosynthesis and certain enzymes
• Plants affected by Zinc Deficiency

  • Rice
  • Banana
• Zinc Deficiency symptoms
• Zinc

  Involved in certain enzyme systems
• Plants affected by Calcium Deficiency

  • Rice
  • Banana