Lily Fungal Disease

(1) Penicillium

Symptoms: During storage, white spots develop over the scale rot spots, followed by fuzzy green-blue patches. After infection, rot will increase gradually even at temperatures as low as -2°C. The pathogen will eventually invade the base of the bulb, rendering the bulb worthless or stunting the plant. Although infected bulbs look unhealthy, plant growth will not be affected during planting as long as the base of the bulb is intact. After planting, the infection will not transfer to the stem and will not infect the plant from the soil.

Prevention and control: Store the bulbs at the recommended minimum temperature; do not plant bulbs whose bases have been damaged: before planting, susceptible bulbs must be soaked in a 1/1000 solution of fungicides such as captan, thiophanate-methyl, carbendazim, etc. for 30 minutes before planting. After planting, maintain a suitable soil temperature.

(2) Bulb and scale rot and stem diseases caused by Fusarium

Symptoms: Plants with bulb and scale rot grow very slowly and have light green leaves. Underground, brown spots appear on the top of the scales, and these spots gradually begin to rot on the sides or where the scales meet the base.

Prevention and control: a. Disinfect the infected soil; b. Plant the lightly or moderately infected bulbs as quickly as possible while keeping the soil temperature low.

(3) Rhizoctonia

Symptoms: If the infection is mild, only the leaves in the soil and the green leaves below the young shoots will be affected. Sunken light brown spots will appear on the leaves. For plants with severe infection, the growth of the upper part will be hindered. The white leaves underground and the leaves at the base of the aboveground part will rot or wilt and fall off, leaving only brown scars on the stems.

Prevention and control: Use soil disinfectants to disinfect suspected infected soil. After disinfection, the soil must be guaranteed to be no longer infected; if the previous crop has been infected, general soil disinfectants cannot be used. In this case, pre-treat the soil with a drug to control Rhizoctonia before planting (completely penetrate the soil to a depth of 10 cm).

(4) Phytophthora

Symptoms: Foot rot (Phytophthora) can stunt growth or cause sudden wilt. Soft rot develops at the base of the stem, which becomes dark green to dark brown and spreads upward. Leaves turn yellow and begin to lose color at the base of the stem. Similar infections often occur on the stem above ground, causing the stem to droop or bend.

Prevention and control: Disinfect infected soil with general soil disinfectants; fungicides that control Pythium during cultivation can also effectively control foot rot; ensure that the soil has good drainage conditions; prevent crops from being in a wet state for a long time after watering: keep the soil temperature as low as possible in summer.

(5) Pythium

Symptoms: This fungus attacks both individual plants and plants in an area. The plants are short, the lower leaves turn yellow, the upper leaves become narrower, the leaves are lighter in color, and often wilt. Plants affected by root rot have shrunken flower buds. When the plants are pulled up, transparent, light brown rot spots can be seen on the bulbs and rhizomes, or they become completely soft and rotten.

Prevention and control: Disinfect infected or suspected infected soil with general soil disinfectants; maintain low soil temperature at the beginning of cultivation, and adopt correct cultivation steps throughout the cultivation period: cultivation in boxes filled with potting soil and peat can control the pythium.

After the crop has emerged or where Pythium infection is likely to occur, a fungicide that can be easily sprayed onto the crop can be used, preferably in the evening. Spraying with water for a few minutes (about three minutes) before spraying will significantly increase the effectiveness of the fungicide and also rinse the crop clean.