Exer 4

• symptom


  manifestation or expression of a plant as a result of disease
• sign


  a pathogen or parts of a pathogen found on the host plant
• local symptoms


  expressed as physiological or structural changes in a limited area of the tissues of the host (galls, spots, cankers)
• systemic symptom


  expressed as the reaction of a greater part of or all of the plants (dwarfing, wilting, yellowing, mosaic)
• primary symptom


  the direct result of pathogen activity on the invaded tissues
• secondary


  the physiological effects on distant and uninvaded organs
• microscopic


  expressions of disease in cell structure or arrangement that can be studied only under the microscope
• macroscopic


  expressions of the disease in the plant or in its parts that can be studied with the unaided eye
• hyperlasia


  a plant overgrowth due to increased cell division
• hypertrophy


  a plant overgrowth due to abnormal cell enlargement
• rosette


  short, bunchy habit of plant growth
• rosette


  symptom

  
• stem-pitting


  symptom

  
• stem-pitting


  characterized by depressions on the stem of the plant
• bunchy


  symptom

  
• bunchy


  leaves progressively becomes dwarfed , upright and bunched at the top of the plant.
• stunt


  symptom

  
• stunt


  reduction in size and vigour
• yellowing/chlorosis


  symptom

  
• yellowing/chlorosis


  discoloration of normally green tissue due to chlorophyll destruction or failure of chlorophyll formation.
• witches' broom


  symptom

  
• witches' broom


  broomlike growth or massed proliferation caused by the dense clustering of branches of woody plants.
• enation


  symptom

  
• enation


  tissue malformation or overgrowth induced by certain virus infections
• scab


  symptom

  
• scab


  roughened, crust-like diseased area on the surface of a plant organ; a disease in which such areas form
• tumor


  symptom

  
• tumor


  uncontrolled overgrowth of tissue or tissues
• gall


  symptom

  
• gall


  a swelling or overgrowth produced on a plant as a result of infection by certain pathogens
• smut


  symptom

  
• smut


  characterized by masses of dark, powdery and sometimes odorous spores
• wilt


  symptom

  
• damping-off


  symptom

  
• dieback


  symptom

  
• wilt


  loss of rigidity and drooping of plant parts generally caused by insufficient water in the plant.
• damping-off


  destruction of seedlings near the soil line, resulting in the seedlings failing over on the ground
• dieback


  progressive death of shoots, branches, and roots generally starting at the tip
• anthracnose


  symptom

  
• blight


  symptom