Grapevine diseases

Major Grapevine diseases are:-

1.Downy mildew: Plasmopara viticola

  • Irregular, yellowish, translucent spots on the upper surface of the leaves.
  • Correspondingly on the lower surface, white, powdery growth on leaves.
  • Affected leaves become, yellow, brown and get dried.
  • Premature defoliation.
  • Dwarfing of tender shoots.
  • Brown, sunken lesions on the stem.
  • White growth of fungus on berries which subsequently becomes leathery and
grapevine downey mildew
Downey mildew in Leaf


Downy mildew
Downy mildew in bunches
  • Later infection of berries results in soft rot symptoms.
  • No cracking of the skin of the berries.
  • Spread: Through sporangia by wind, rain etc.
  • Survival: As oospores present in the infected leaves, shoots and berries. Also as dormant mycelium in infected twigs.
  • Optimum temperature: 20-22°C
  • Relative humidity: 80-100 percent
  • Spray Bordeaux mixture 1 % or Metalaxyl + Mancozeb 0.4 %.


2.Powdery mildew: Uncinula necator

grapes powdery mildew

  • Powdery growth mostly on the upper surface of the leaves.
  • Malformation and discolouration of affected leaves.
  • Discolouration of the stem to dark brown.
  • Floral infection results in shedding of flowers and poor fruit set.
  • Early berry infection results in shedding of affected berries.
  • Powdery growth is visible on older berries and the infection results in the
  • Cracking of skin of the berries.
  • It spread through air-borne conidia
  • Through dormant mycelium and conidia present in the infected shoots and buds.
  • Sultry warm conditions with the dull cloudy weather, highly favourable.
  • Spray Inorganic sulphur 0.25 % or Chinomethionate 0.1 % or Dinocap 0.05 %.


3.Bird’s Eye Spot/Anthracnos: Gloeosporium ampelophagum Elsinoe amphelina

  • The disease appears first as dark red spots on the berry.
  • Later, these spots are circular, sunken, ashy-gray and in late stages these spots are surrounded by a dark margin which gives it the “bird’s-eye rot” appearance.
  • The spots vary in size from 1/4 inch in diameter to about half the fruit.
  • The fungus also attacks shoots, tendrils, petioles, leaf veins, and fruit stems.
  • Numerous spots sometimes occur on the young shoots.
  • These spots may unite and girdle the stem, causing death of the tips.
  • Spots on petioles and leaves cause them to curl or become distorted
  • Seed-borne-infected vine, cuttings and air-borne conidia
  • As dormant mycelium in the infected stem-cankers
  • Warm wet weather
  • Low lying and badly drained soils.
  • Removal of infected twigs
  • Copper oxychloride 0.2% or Mancozeb 0.25%




  • TamilNadu Agritech Portal


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