VI. Plant Pathogens as Causes of Plant Diseases

Question 1

DISEASE

Answer 1

1. caused by pathogen
2. communicable
3. interaction between host, pathogen, and environment

Question 2

DISORDER

Answer 2

1. caused by soil and environment factors
2. non-communicable
3. no interaction between host and pathogen

Question 3

PHYSIOLOGICAL DISORDERS

Answer 3

1. temperature
2. lack of oxygen
3. air pollutants
4. nutrient deficiency

Question 4

NUTRIENT DEFICIENCIES IN PLANTS

Answer 4

1. nitrogen (rice, corn, peanut)
2. phosphorus (apple, pear, rice)
3. potassium (rice, cotton)
4. calcium (tomato)
5. iron (bean)
6. manganese (bean)
7. copper (potato)
8. zinc (citrus)
9. boron (beet)
10. molybdenum (onion)

Question 5

NUTRIENT TOXICITY IN PLANTS

Answer 5

1. boron (grapefruit)
2. sodium (grapevine)
3. iron (turf grass)

Question 6

PLANT PATHOGENS

Answer 6

1. fungi
2. bacteria
3. nematodes
4. virus
5. viroids
6. phytoplasma
7. flagellate protozoa
8. parasitic flowering plants