Common pest and disease control methods for lilies, explained in one article

Lilies originated in China. They are distributed in the southeast and southwest, as well as Henan, Hebei, Shaanxi and Gansu, where wild and cultivated plants grow in various places, mainly used as cut flowers and for garden displays as potted ornamentals. The bulbs are used for food and medicine, the fresh flowers contain aromatic oil used as a fragrance, and the fruit is eaten. It is a cold-hardy, autumn-planted scaly bulbous herbaceous flower. There are many cultivated varieties, and besides white, the flowers also come in yellow, red, light red, variegated and other colors.

1. In the middle and late growth stages, the bulb and the root-growing part of the stem are prone to root rot, showing bright dark-brown decay spots

At the base of the plant stem, base rot easily occurs, causing the leaves to droop and turn yellow; the leaves can also be infected by leaf spot disease, causing the plant to stop growing. With bulb and scale rot, brown to dark-brown spots appear on the underground stem, gradually spreading into the interior of the stem and causing the bulb to rot. There is also a damping-off disease, in which the young leaves of infected plants show yellow-green or white spots, and in severe cases the leaves turn brown and curl.

Control: Damping-off is a physiological disease, while the other diseases are caused by fungi. You can use 50% carbendazim at 1 kg per mu for root drenching, or mix it with a 100-fold dilution of 50% amobam. Note that infected plants should be pulled out immediately once symptoms appear, and control measures should be taken at once.

2. Lily symptomless virus, also called lily virus or "lily curl-stripe virus"

(1) Symptoms: generally no symptoms, or mild mottling and crinkled stripes on the leaves. It easily forms mixed infections; when co-infected with CMV it produces necrotic spots, and when co-infected with tulip breaking virus it produces brown necrotic spots or stripes.

(2) Distribution: It occurs in both the south and north of the Yangtze River in China, and is especially severe in Xiamen.

(3) Pathogen: The virus particles are filamentous, long and slightly curved, with a length of 650 nm and a diameter of 18 nm. It is transmitted by sap and by aphids. Lilium longiflorum (Easter lily) is used as a diagnostic host. Lily bulbs sold on the market commonly carry the virus.

(4) Control: Choose virus-free bulbs as planting stock. Strengthen aphid control. Lily symptomless virus can also harm tulips, so these two flowers must not be mixed, interplanted or grown in succession.

Lily seeds have an extremely short lifespan; after half a year of storage they lose their ability to germinate, and seedlings grown from seed need many years of cultivation before they can bloom. Therefore, propagation is done by cuttings: break the scales off an old bulb, keeping a small part of the basal plate at the base of each scale, bury them in clean fine sand or mud, leaving the upper half of the scales exposed above the soil surface, and keep them indoors or in a shade shed. After 3 to 4 months, 1 to 2 small bulbs will grow; break these off and plant them in a seedbed to continue growing. Pot them up in spring, and after 3 years of cultivation they can bloom.

After lily bulbs are dug up, low-temperature treatment and storage are necessary to achieve year-round flowering. First keep them at 15°C for 4 to 5 days, then lower the temperature to 9°C and keep them there for 3 weeks, then lower it to 0°C to 5°C and keep them there for 8 weeks, which completes the low-temperature vernalization stage, after which they can enter long-term storage at -2°C. Before storage, however, they must be graded, cleaned, disinfected and packaged. After digging them up, separate the large and small bulbs. Small bulbs that have already sprouted or grown new roots can be planted immediately; large bulbs that have grown new roots should be given low-temperature storage.