Prevention and control of orchid diseases and insect pests

Pest control is also an important part of orchid cultivation, if the control is not timely, leading to rampant diseases and insect pests, it will cause unnecessary losses. In the prevention and control of orchid diseases and insect pests, it is necessary to achieve the principle of "prevention first, comprehensive control". The newly purchased orchid plants should be strictly inspected, and once they are found to be infected with diseases and insect pests, they should be treated in isolation and cannot be put together with other healthy orchid plants until the diseases and insect pests are cured.

The common diseases and insect pests of Cymbidium are as follows:

1. Disease

(1) Leaf spot disease, which is more common in Cateran plants. The infected leaves appeared black dots at the initial stage, surrounded by water quality yellow circles, and then turned into round or oval spots. This disease is mostly caused by high humidity.

Prevention and treatment: improve ventilation conditions, reduce humidity, diseased leaves should be cut off immediately, and 1% Bordeaux liquid should be sprayed in the well.

(2) anthracnose is mainly harmful to orchid leaves, and Cymbidium is the most susceptible to anthracnose. Most of the inducements are poor ventilation and muggy. The symptoms are oval disease spots on the leaf surface, from yellow to black, and in severe cases, the whole leaf turns black.

Control methods: cut off diseased leaves, strengthen ventilation and reduce humidity, spray with 500 times solution of carbendazim, chlorothalonil or methyl topiramate, and then spray every 10 to 15 days.

(3) Stem rot is a common and serious disease. The disease often occurs at the base of the stem, then extends to the roots and leaves, and in severe cases the whole plant dies.

Prevention and treatment: stop watering immediately when the disease is found, and let the sun shine on the orchid plant, and spray it with 1% Bordeaux solution or 600-fold solution of Dysen zinc and 500-fold solution of chlorothalonil.

(4) soft rot-mainly harmful to Cartland Republican Phalaenopsis. In the early stage, there are water-like green spots at the end of the leaves, like scalded by hot water, and the leaf tissue is water-filled and rotten, accompanied by bad smell.

Prevention and treatment: cut off the diseased leaves as soon as they appear, sprinkle the wound with charcoal powder or help hundreds of chlorothalonil to disinfect, and then spray the plant with 1% Bordeaux solution.

(5) Brown rot, which mainly harms Paphiopedilum. The disease develops very fast, and when you find it, the plant is dead, the whole plant turns black, and the mesophyll tissue becomes mushy.

Prevention and treatment: stop watering immediately, cut off the diseased plants, disinfect the wound with charcoal powder or chlorothalonil, and then spray with 1% Bordeaux solution.

(6) flower rot-Cartland is the most common disease. In the main flowering period, the disease is easy to occur when the temperature inside the greenhouse is high and the temperature outside the greenhouse is low. Small brown spots appeared on the petals at the beginning, and then the spots became larger and increased, but the disease was limited to flowers.

Prevention and treatment: if you find a sudden drop in temperature before flowering, immediately reduce indoor humidity and immediately spray your own stone sulfur mixture to prevent flower rot.

(7) Rust, which first appears on the leaves, producing yellowish-brown powder. The disease is easy to occur in low temperature and high humidity, mainly in Cartland, Phalaenopsis, orchid, Dendrobium and Cymbidium.

Prevention and control methods: do not wet the leaves when watering, wet weather such as watering, strengthen ventilation. The diseased leaves were cut off and sprayed with 1% stone-sulfur mixture.

(8) viral disease-a disease that is difficult to treat. The virus disease is transmitted by juice-sucking insects such as aphids. The leaves and flowers are yellow at first, then turn into black spots or markings, and then the leaves and flowers shrink.

Methods of prevention and treatment; as soon as the diseased plant is found, it will be discarded and buried deep to prevent infection. At present, there is no specific cure.

2. Insect pests

(l) scale insect, which is the most harmful pest of Cymbidium. It often occurs in the case of high temperature and humidity and poor ventilation. The insect is attached to the plant and is protected by a wax shell to absorb juice for a living. In severe cases, the plants are full of flowers, which causes the orchid plants to shrink and die.

Prevention and treatment: improve the ventilation environment, spray with 1000 times of omethoate or 1000 times of malathion. A small amount can be wiped with a small brush dipped in soapy water.

(2) Red spiders-often live in groups on the back or surface of leaves to absorb the juice of orchids, so that the damaged parts become yellow spots, affecting the beauty and growth of leaves.

Prevention and control method: kill with triclofenac 1000 times liquid indignation, if use omethoate 40% liquid plus 800x water spray, the effect is better.

(3) aphids-aphids that harm orchids are often moved by ants to succulent buds or petals during flowering, and the honeydew discharged is for ants to eat. in serious cases, the buds can not open and the flower color becomes dim.

Prevention and control method: spray water 300 times with 20% dimethoate EC 500 times, or with 50% of enemy people's original solution. Wipe off with a small amount of cloth.

(4) cloth bag beetle-under the cover of a self-made silk "cloth bag", it climbs on the leaves of orchids and gnaws on the leaves and flower buds. It mainly harms the succulent leaves of Cartland and other orchids.

Prevention and control methods: kill as soon as you catch, or spray water 300 times with 50% dichlorvos.

(5) Leafminer, which is the larva of leaf miner, eats the mesophyll under the leaf epidermis, leaving an obvious "tunnel" where it has been eaten, which forms a white line on the leaf surface. in severe cases, it can cause the whole leaf necrosis and leaf miner to occur on the common leaves of Paphiopedilum.

Prevention and control method: when this insect is found, a small number of people will pick the worm to death with a needle. More than 40% omethoate can be sprayed with 1000 times solution.

(6) Snail-a kind of mollusk that rises at night and day. The mouth often lurks in the gap at the bottom of the basin, coming out at night to nibble on the buds and flowers of orchid plants, which makes Yang Lanqi very annoying.

Prevention and control methods: a small number of people are removed during the day or night, and sprinkle lime powder around the benefit to prevent it from climbing up the plant to eat. In large quantities, rotten vegetable leaves can be put around the orchid basin as bait to make the snail climb into the rotten vegetable leaves and gnaw them off.

Li Shaoqiu, Hu Songhua