To master the methods of topdressing edible fungi and the occurrence and control of soft rot of Cymbidium.

Clivia is a perennial herbaceous flower belonging to Clivia of Amaryllidaceae. Since 1932, it has been cultivated in various places since it was introduced into China from Japan. However, due to the occurrence and damage of Clivia soft rot, the whole plant often dies and causes great losses.

I. Symptoms

The disease mainly damages Clivia pseudobulb and leaves. The stem base disease first appeared water-stained small freckles, gradually expanded into light brown spots, spread to pseudobulbs, so that the tissue erosion was soft rot and odor. The disease spots at the stem base can also extend along the veins to the leaves. The leaves are water-stained at the initial stage, and then rapidly expand to appear erosive and translucent. There are yellow halos around the disease spots, and the halos are broadband. Serious, the whole leaf erosion disintegration was wet rot.

The pathogens of the disease were bacteria, mainly Erwinia chrysanthemi and Erwinia soft-rot black-stemmed diseased species.

II. Pathogenesis

Pathogenic bacteria overwintering in soil or diseased plant residues can occur from June to November, but mostly in summer high temperature and wet period, poor ventilation conducive to disease spread and development. Pathogens can survive in soil for several months, and diseased soil is an important source of infection. Therefore, incomplete soil disinfection can easily lead to the occurrence of this disease. In addition, it can be transmitted by water currents, insects, contact between diseased and healthy leaves, or by handling tools. Pathogens invade the plant from the wound, can occur within a few days, and can be repeatedly infected during the growing season. This disease can be induced if the stem center of Clivia is partially rained or sprayed carelessly into the stem center in summer. Besides Clivia, the pathogen can also cause diseases of chrysanthemum, dianthus, dahlia, begonia and myrtle.

III. Prevention and control methods

1。Soil disinfection: In order to prevent the occurrence of soft rot early, the pot soil for planting flowers should be disinfected before transplantation. The soil can be used for 0. 5%-1% formalin for disinfection, about 10g per square meter; chloropicrin 60-120g/square meter or 70% pentachloronitrobenzene 8-10g/square meter for disinfection.

Used flowerpots and contaminated tools should also be cleaned and disinfected with 1% copper sulfate before use. Do not water too much at ordinary times, lest the pot soil is too wet.

2。Agricultural control: timely removal or removal of diseased plants destroyed; planting and transplanting do not bruise plants, lest wound infection; during the disease pay attention to drainage, so that rhizomes maintain monotony, lest damage roots, rhizomes, bulbs occur erosion.

3。Chemical control: after the disease, spraying agricultural streptomycin 1000 times or 150-200 times Bordeaux mixture every 1 month or so can control the spread of the disease. At the same time, when pests are found, they should be prevented in time to reduce wounds and reduce the incidence rate.