Necrotic

Cards (22)

  • A. Necrotic – involve death of protoplast, cells or tissues
  • 1. Blast – blighting or sudden death of buds, inflorescences, or young fruit (rice blast)
  • 1. Bleeding/ Gumming or Gummosis/ Leak – chronic flow of sap from wounds or other injuries usually accompanied by odor or fermentation (stem bleeding of coconut)
  • 1. Blight – sudden or total killing of shoots, limbs, and blossom; resembles scorch but not as localized (bacterial blight of cassava)
  • 1. Blotch – large, irregular spots on leaves or fruits with necrotic injury of epidemic cells
  • 1. Canker – sunken lesions in cortical tissues of stems, twigs, tubers, and roots. Differ from rot in having a definite line of demarcation affected (citrus canker)
  • 1. Damping off – decay of seed in soil or rapid death of germinating seedlings.
  • 1. Dieback – drying of leaves starting from the tips of twigs or branches (citrus die back)
  • 1. Firing – drying and dying of leaves (verticillium wilt of eggplant)
  • 1. Flecks – extremely tiny spots on leaves, fruits, stems etc.
  • 1. Mummification – final stage in certain types of rots, usually in fruit disease, where dried fruit is called a “mummy”
  • 1. Net necrosis – irregular anatomizing, necrotic lines giving a netted appearance (necrosis in potato tubers)
  • 1. Pitting – dying of small, localized areas in fleshy or woody tissues beneath healthy external tissues, leaving definite depressions (virus stem – pitting in citrus)
  • 1. Rot – dead tissues in an advanced stage of disintegration
  • 1. Scald - blanching of the epidermis and adjacent tissues of young shoots, foliage and fruit generally superficial (sunscald of peppers and tomatoes)
  • 1. Scorch – suddenly death and browning of large indefinite areas in leaves and fruit (toxicity from pesticides, drought, or wind injury)
  • 1. Shothole – necrotic spotting of leaves, in which diseased tissue dries and drops leaving a hole
  • 1. Spot – circular to irregular dead area in which tissue dries out, color often brown, black to almost white; reddish or yellowish tissue may surround area; characterized as location by names as leaf and fruit spot.
  • 1. Streak or stripe – elongated, narrow, parallel, necrotic lesions especially in the leaf diseased of cereals and grasses (helminthosporium disease)
  • Firing
    (verticillium wilt of eggplant)
  • Pitting
    (virus stem – pitting in citrus)
  • Streak or stripe
    1. eaf diseased of cereals and grasses (helminthosporium disease)