Diseases of Gourds

Major diseases of Gourds are:-

1.Downy mildew: Pseudoperonospora cubensis

Symptom:

• Symptoms resembling mosaic viz, pale green areas separated by dark green areas appear on the upper surface of the leaf.
• During the wet season, the corresponding lower surface is covered with faint purplish fungal growth.
• The entire leaf dries up quickly.

Management:

• Use of bed system with wide spacing with good drainage and air movement and exposure to sun help to check the disease development.
• Spray with Moncozeb 0.2 % or Chlorothalonil 0.2% or Difolaton 0.2% or Ridomil MZ 72 0.1%
• Seed treatment with Apron SD 35 @ 2 g./kg. followed by spraying with Mancozeb 0.2% is effective in reducing the disease.

2.Powdery mildew: Erysiphe cichoracearum

Symptom:

• Powdery mildew is especially prevalent in hot dry conditions.
• White or brown mealy growth will be found on upper and lower surfaces and stems.
• Under severe infestations, the plant will be weakened and stunted.

Management:

• The disease can be controlled by spraying Wettable sulphur 0.1%.

3.Mosaic: PRSV/CMV

Symptom:

• A virus distributed world wide, affecting most cucurbits but rarely affecting watermelon.
• New growth is cupped downward, and leaves are severely mottled with alternating light green and dark green patches.
• Plants are stunted, and fruits are covered with bumpy protrusions. Severely affected cucumber fruit may be almost entirely white.

Management:

• The virus is readily transferred by aphids and survives on a wide variety of plants.
• Varietal resistance is the primary management tool and eliminating weeds and infected perennial ornamentals that may harbour the virus is critical.
• Spray with any one of the systemic insecticides.

Source-

• TamilNadu Agritech Portal