What's eating my daikon 'minowase'?

Daikon 'Minowase' is a giant Japanese radish whose leaves and swollen taproot are targeted by flea beetles, aphids, and root maggots. Cabbage root fly (root maggot) is the most damaging pest, tunneling directly into the prized edible root and causing it to rot. Brassica collars and row covers are the key defenses.

Larvae tunnel into and through the developing taproot; roots turn brown and rotten; plant wilts from root destruction Brassica collars (10 cm discs of cardboard or purpose-made mats) around each stem base to block egg-laying; fine mesh row cover; avoid planting near previous brassica crops

Tiny holes across all leaf surfaces; severe on seedlings; reduces photosynthetic capacity needed for large root development Row cover at sowing; diatomaceous earth as a surface barrier; pyrethrin spray for heavy seedling outbreaks

Grey colonies on leaf undersides and crowns; distorted leaves; reduced plant vigor and root size Strong water jets; insecticidal soap; encourage ladybirds and lacewings

Surface scarring and gouging of the upper exposed root shoulder; ragged holes in leaves near ground level Iron phosphate pellets; remove mulch where slugs shelter; hand-pick after dark