Pest and disease control methods for the Chinese medicinal herb Ophiopogon japonicus

On plants damaged by nematodes, root knots of varying sizes form on the roots, appearing like a string of beads; from these root knots, adventitious fibrous roots may grow again, and the tips of these fibrous roots are once more infected by nematodes, forming small root knots. Root knots also form on the tuberous roots, the fibrous roots become shortened, and the surface skin becomes rough and cracked, turning reddish-brown. When a root knot is cut open, a white, glistening spherical body is visible, which is the female adult.

Control methods:

1. Practice good crop rotation. Do not rotate with crops such as tobacco, Chinese milk vetch, cowpea, potato, cucurbits, Atractylodes macrocephala, or Salvia miltiorrhiza; rotation with grass-family crops is best.

2. Select disease-free seedlings and prune away all old roots to prevent carrying nematodes.

3. Carry out soil treatment. Before planting, apply 5 kg of 5% ethoprophos granules per mu into the soil of the raised bed; alternatively, use 40% isofenphos-methyl emulsifiable concentrate, 1 kg per mu plus an appropriate amount of fine sand, spread it into the soil of the raised bed, mix evenly with the topsoil, and then plant.