Orchid cultivation treasure book: medicinal plant orchid (orchid) anthracnose

Orchid cultivation: medicinal plant orchid (orchid) anthracnose

The scientific name of orchid Cymbidiumspp. It belongs to perennial herbs of Orchidaceae. Including Jianlan, multi-flower orchid, mountain orchid three kinds. The roots, leaves, flowers and fruits of orchids can be used as medicine. It has the effect of nourishing yin and clearing lung, resolving phlegm and relieving cough. It is cultivated in Zhejiang, Shanghai, Jiangsu, Anhui, Jiangxi, Hubei, Hunan, Sichuan, Guizhou, Yunnan, Guangdong and Fujian.

Anthrax

The main symptoms are damage to leaves and fruits. Leaf infection often occurs at the tip or edge of the leaf, the primary round to oval black-brown spots, then gradually expand, the center of the spot is light brown or gray-white, the edge is dark brown to dark brown, the boundary of the disease is obvious, and the expansion of the spot is limited by the vein of the leaf. the spot on the leaf tip is triangular and the leaf edge is semicircular. The fruit is infected with fusiform black-brown spots, and small black spots can be produced in the later stage of the disease, that is, the conidia disk of pathogens.

The pathogen G10merellacingulata (Stonem.) Spauld.etSchrenk, which belongs to the subphylum ascomycetes, is called the perithecium. The anamorph is Colletortrich μ mg10eosporioidesPenz. It is called Colletotrichum gloeosporioides, which belongs to the subphylum fungus. For morphological characteristics, see anthracnose of Chinese wolfberry.

The pathogens of transmission and disease conditions overwintered mainly by mycelium in diseased leaf tissue, and the southern ones could also overwinter by conidia. In April of the following year, the mycelium of the disease department resumed its activity and expanded to the vicinity to produce a new reddish-brown disease spot. The conidia produced on the disease spot were transmitted by wind and rain. When there was water film or water droplets on the leaf surface, the conidia germinated and invaded from the wound. The disease occurred after 2mi incubation for 3 weeks. The temperature is 20-29 ℃ and the relative humidity is higher than 80%. The disease of the old leaves in Shanghai began in early April, and the disease expanded rapidly in the rainy season, and gradually stopped after July; most of the new leaves began to occur in August, and the disease was serious in rainy or overplanted areas.

Control methods (1) strengthen cultivation management. Orchid nursery or greenhouse with shading net shade, ventilation and light, thoroughly cut off the diseased leaves on the plant in winter, remove the fallen leaves on the ground, and burn them centrally. (2) spraying 25% carbendazim wettable powder 500 times or 36% carbendazim suspension 600 times and 25% carbendazim EC 800 times at the initial stage of the disease. Once every 10 days or so, continuous prevention and treatment for 3 times.