MySheen

Control methods of Rhizopus soft rot of lily bulb

Published: 2024-11-22 Author: mysheen
Last Updated: 2024/11/22, First, the symptoms of damage: during the storage or transportation of the lily bulb, there are primary water stains on the outer skin, and then the color becomes darker, with a slightly pungent smell, the bulb becomes soft, and in serious cases, the bulb has destructive decay, and sometimes there is a thick mycelium layer on the bulb, that is, the cyst peduncle and sporangium of the pathogen. Second, the shape of the pathogen is special.

First, the symptoms of damage: during the storage or transportation of the lily bulb, there are primary water stains on the outer skin, and then the color becomes darker, with a slightly pungent smell, the bulb becomes soft, and in serious cases, the bulb has destructive decay, and sometimes there is a thick mycelium layer on the bulb, that is, the cyst peduncle and sporangium of the pathogen. 2. Morphological characteristics of pathogens: the pathogen is Rhizopusstolonifer (Ehr.exFr.) Vuill. It is called Rhizopus creeping Rhizopus (Rhizopus nigricans), which belongs to zygotic fungi. The hyphae are colorless at first, then become dark brown, and form creeping roots. The asexual sporangium is clustered at the root node, erect and dark brown, with a spherical sporangium at the top, and many dark round spores are produced in the cyst, which are 11-14 microns in size. many bulbs are contaminated by the cyst stalks outside the root nodes of the creeping roots to produce patches of mold; the sexual state produces black zygotic spores, spherical, with protuberances on the surface. 3. The characteristics of the disease: the bacteria existed in the air or attached to the injured bulb or bulb adhering to the soil and the dead branches of the packaging material. the pathogen invaded the outer skin of the bulb from the wound, the hyphae extended to the base of the bulb, and then extended to other scales. the cyst spores of the diseased part were re-infected by airflow transmission. The suitable temperature for the disease is 15-25 ℃, and the relative humidity is 76-86%. Under the condition of poor ventilation, the bulbs can all rot in 2-4 days. Fourth, control methods: (1) when harvesting the bulb, do everything possible to reduce the wound, keep the pit temperature 8-10 ℃ and the relative humidity 70-75% during storage. (2) the bulbs of oriental lilies can be immersed in 27-29 ℃ of 50% carbendazim solution (50g of carbendazim every 4 minutes) for 15-25 minutes to control Rhizopus creeping, Penicillium, Fusarium and so on. Other varieties should be tested before use.

 
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