Special characteristics and control of orchid nematodes

Nematodes, also known as worms, are mostly parasitic, many of which are also parasitic on plant leaves, buds, flowers, roots and so on. Like humid environment, often do harm in high temperature and rainy season, overwintering in soil or on plants. There are dozens of known nematodes that harm flowers, such as dangerous nematodes that harm orchids, which are caused by sword-shaped nematodes, root-knot nematodes of shrimp ridges are caused by root-knot nematodes, and Wandailan yellow bud blight is caused by nematodes. These nematodes can infect many plants.

Nematodes parasitic on the leaves will make the leaves appear yellow or brown patches, causing necrosis, withering and even deciduous leaves, resulting in slow growth and sterile development of the whole plant. Parasitic on the flower bud, making it dry or unable to bud; parasitic on the root, causing the root to show a string of beaded nodules or nodules, in which the white round particles are male and female nematodes and their eggs. The disease will eventually cause poor growth of the aboveground part, smaller leaf shape, yellowing of leaf color, reduction of leaf number, dwarf and weakness of the plant, and death of the whole plant in serious cases.

The first thing to control nematodes is to remove the pathogen, pull out and burn the diseased plants. The soil should be irrigated with 1000 times of omethoate. The soil can also be treated with 10% gram phosphorus granules 1.5 × 2 g / kg, or aldicarb granules 1.2 × 5.6 g / kg.