MySheen

Control of Fusarium Wilt of Cymbidium

Published: 2024-11-08 Author: mysheen
Last Updated: 2024/11/08, Symptomatic Fusarium wilt is a serious disease of Cymbidium. Seriously diseased plants die in a few weeks, and generally diseased plants can survive for a year or more. The aboveground symptoms of Fusarium wilt are similar to those caused by RhizoctoniasolaniKuhn, that is, the leaves turn yellow and wilt, the pseudo-bulbs become thinner and twisted, and finally lead to root rot. But Fusarium caused a globular purplish red color, and finally the rhizome was invaded and turned purplish red. When the disease is serious, the pseudobulb decays deeply. Onset of disease

Symptom blight is a serious disease of orchids. A seriously ill plant dies within a few weeks. A typical diseased plant can live for a year or more. The aboveground plant symptoms of Fusarium wilt are similar to those caused by Rhizoctonia solani Kuhn, i.e., the leaves turn yellow and wilt, the pseudobulbs become thin and twisted, and finally the roots rot. However, fusarium causes a spherical purple-red color, and finally the rhizome is also damaged and turns purple-red. When the disease is serious, the pseudobulb will rot deeply.

Conditions of onset:

(1) Soil temperature 28℃, soil moisture, continuous cropping pot, transplanting or injured roots, plant growth potential weak disease.

(2) acid soil and nematodes feeding on the wound caused by the disease. Below 21℃ or above 33℃, the disease expands slowly. Fusarium oxysporum Schlecht., It belongs to subphylum Semi-fungi. Strain white, pink, violet to purple. Small conidia are born in aerial hyphae, aggregated into false heads, numerous, oval, elliptic, cylindrical, straight or curved. Large conidia thin-walled, born on aerial hyphae, rarely born in conidia peduncle or myxospore mass, spindle-shaped or sickle-shaped, sickle-shaped curved, elliptically-curved, sub-crescent-shaped or straight, thin apical cells, peduncle with peduncle. Chlamydospore walls smooth or rough, numerous, interhyphal and interconidia, terminal and intermittent, solitary or paired.

Control methods:

1. Because the pathogen can parasitize and satiate, the infected plants and their residues must be completely burned, and new pots and new soil must be replaced to replant orchids.

2. At the early stage of disease, spray 50% carbendazim WP or 36% methyl sulfur bacteria suspension 500 times, in addition to 20% methyl chlorphos EC 1000 times or 10% Zhiweiling aqueous solution 300 times or 12.5% synergistic carbendazim concentrated solvent 200 times irrigation roots.

 
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