PESTS

PESTS

Carrot Rust Fly:
  • Larva burrows into the roots, often causing it to become misshapen and subject to decay, leaves become rusty or dried.
Control measures:
  • Mix folidol M (2%) or malathion dust (5%) @ 20-25kg/ha in the soil at the time of soil preparation.
Aphids
  • These are small in size, both adults and nymphs suck sap from leaves and flowers due to which, the plant become weak and leaves curl.
Control measures:
  • Spray malathion (0.05%) at 15days interval on root crop. On seed crop, spray oxy-demeton methyl (0.025%).
Mustard saw fly: (Athalia promixa)
  • Adult feed on pods and leaves which show holes.
  • Seed crop is also adversely affected.
Control measures:
  • Mix folidol M (2%) or malathion dust (5%) @ 20-25kg/ha in the soil at the time of soil preparation.
Physiological Disorders
1. Root splitting: Splitting or cracking of carrot roots is a major problem.

Possible Reasons:
  • Wider spacing as larger roots tend to split more
  • Dry weather followed by wet weather is conducive to cracking of roots.
  • Increases as the amount of N in the soil increases
  • Early cultivars tend to split more readily than late ones.
Correction:
  • Maintain optimum moisture in the field
  • Harvest the crop at right maturity stage.
  • Grow resistant varieties
  • Sow the seeds at close spacing
  • Supply recommended dose of nitrogen
2. Cavity spot
  • It appears as a cavity in the cortex. In most cases, the subtending epidermis collapses to form a pitted lesion.
Possible Reasons:
  • Calcium deficiency associated with an increased accumulation of K and decreased accumulation of Ca.
Correction:
  • Incorporate calcium containing fertilizers in the soil.
  • Harvest the roots at optimum maturity.
3. Forking: A common disorder in carrot and radish formed by the enlargement of secondary root growth.

Possible Reasons:
  • Excess moisture during the root development is the cause. It occurs on heavy soils due to soil compactness.
Correction:
  • Avoid excessive moisture
  • Avoid heavy soil for root production
Last modified: Wednesday, 20 June 2012, 3:50 AM