Introduction to Major Field Crops

Plant Protection

Insect Pests
Mustard Saw Fly: The larvae of mustard saw fly feed on leaves and make holes. In case of severe infestation entire leaf lamina is eaten. The female of this insect have saw like ovipositor thus called saw fly. Infestation may be controlled by dusting Endosulfan dust (4%) or Quinolphos(1.5%)or Malathion(5%) or Methyl parathion (2%) at 20-25 kg/ha in morning. Spray of Monocrotophos at 0.2 per cent also takes care of this insect.

Aphid: Both nymph and adult infest the crop by sucking the cellsap from leaves, stalk and inflorescence and siliquae. Infestation is more severe under cloudy conditions and cause severe damage if occur at flowering or pod formation. It is controlled by dusting the crop with Methyl parathion (2%) or Malathion (5%)at 20-25 kg/ha or spraying ofPhosphomiden(0.05%) ml or Endosulfan 35 EC or Malathion 50 EC (0.2%) or Monocrotophos (0.05%).

Painted Bug: The nymph and adult suck the cell sap from leaves and top stem. Dusting the crop with Endosulfan(4%) or Quinalphos(1.5%)or Malathion(5%) at 20-25 kg/ha or spray with MonocrotophosAT 0.2 per cent checks the infestation.

Diseases
Blight: The disease is identified by appearance of concentric black spots on leaves, stalk and pods. To control the disease spray Ridomil(0.2%), Mencozeb or Captafal or Zineb(0.4 %).

Downey Mildew: The leaves of infected plant have yellow, irregular spots on upper side and whitish spots on lower side. Use of clean and healthy seeds for sowing, prevent infestation. Spraying of Dithane M-45 or Metalaxyl followed by Mancozeb(0.2%)decreases spread of disease.

Powdery Mildew: Symptoms of disease are deposition of greyish white powder in leaves. On increase infestation white powdery growth changes to dark grey and black and leaves develop small-big lesions resulting to death of leaf. Infestation of disease is more under cloudy conditions. It is controlled by applying 20 kg Sulphur dust or spraying of wettable Sulphur(0.5%).

White Blister: Leaves, stalk and floral parts have white raised blisters resulting into deformation of inflorescence. To prevent infection, use of healthy seed is necessary. Adoption of crop rotation to break continuity of disease checks its spread. Two sprayings with Zineb(0.2%)at 10 days interval check its further infestation and spread.