Major diseases of Gourds are:-
1.Downy mildew: Pseudoperonospora cubensis
- 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.
- 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
- 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.
- The disease can be controlled by spraying Wettable sulphur 0.1%.
- 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.
- 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.
- TamilNadu Agritech Portal