Symptom Identification and Prevention Methods of Daylily Rust
In daily life we may often hear the saying, "I've been waiting so long the daylily has gone cold," used to describe having waited for someone for a very long time. This shows that the daylily is certainly well known in our lives. Let's learn about the daylily together below.
The Growing Environment of the Daylily
The daylily tolerates poor soil and drought, and has no strict requirements for soil; it can be cultivated at field edges or on hillsides. It adapts to a wide range of light conditions and can be intercropped with relatively tall crops. The above-ground part of the daylily is not cold-tolerant, while the underground part tolerates low temperatures of -10°C. It dislikes overly wet or waterlogged soil. When the average ten-day temperature is above 5°C, the seedlings begin to emerge, and the suitable temperature for leaf growth is 15°C to 20°C; the flowering period requires a higher temperature, with 20°C to 25°C being more suitable.
Morphological Characteristics of the Daylily
Hemerocallis plicata is a perennial herb, 30-65 cm tall. The roots are clustered, fleshy, with the root tips swollen into a spindle shape. The leaves are basal, narrowly strap-shaped, overlapping at the lower part and gradually flattening upward, about 40-60 cm long and 2 cm to 4 cm wide, with entire margins, and the midrib protruding on the underside of the leaf.
The flower stem emerges from the leaf axil, with branches at the top bearing flowers, several flowers per stem, large, orange-yellow, funnel-shaped, with the perianth split into 6 lobes. The capsule is leathery, elliptical. The seeds are black and shiny. The plant is generally rather tall; the roots are nearly fleshy, often with spindle-shaped swellings in the middle and lower parts. There are 7-20 leaves, 50-130 cm long and 6-25 mm wide.
The flower scape varies in length, generally slightly longer than the leaves, triangular at the base, more or less cylindrical above, with branches; the bracts are lanceolate, the lower ones up to 3-10 cm long, gradually shortening from bottom to top, 3-6 mm wide; the pedicels are relatively short, usually less than 1 cm long; there are many flowers, up to more than 100; the perianth is pale yellow, sometimes with a dark purple tip in the bud stage; the perianth tube is 3-5 cm long, and the perianth lobes are (6-)7-12 cm long, with the inner three 2-3 cm wide. The capsule is obtusely triangular-elliptical, 3-5 cm long. There are more than 20 seeds, black, ridged, and it takes 40-60 days from flowering to seed maturity. The flowering and fruiting period is May to September.
Symptoms and Prevention Methods of Daylily Rust
1. Symptom characteristics of daylily rust:
It mainly harms the leaves, and can also harm the flower scape. When the leaves are infected, orange-red blister spots are scattered on the underside of the leaves in the early stage, and the spore spots rupture and release orange-yellow powder, namely the uredinia. In the later stage, black telia are scattered on the leaf surface, but in the south, telia may not necessarily form.
2. Pathogen and disease occurrence characteristics of daylily rust:
The pathogen is Puccinia hemerocallidis Thüm. [Puccinia hemerocallidis Thüm.], of the Basidiomycota and Uredinales. In the north, the pathogen overwinters as teliospores on diseased plants and diseased residues; in the south, the pathogen spreads and infects between hosts as urediniospores and has no obvious overwintering period. Suitable temperature (25-28°C) and high humidity (relative humidity above 85%) are conducive to the occurrence and spread of the disease. Low-lying terrain, poor drainage, or thin and poor soil, insufficient fertilizer, or excessive application of nitrogen fertilizer all tend to aggravate the disease. There are differences in disease resistance among varieties. Varieties such as Chazihua (Saozihua) and Hongjinhua have weaker resistance, becoming diseased early and severely, while varieties such as Jingzhouhua and Mengzihua (Bangchuihua) have stronger resistance, becoming diseased later and suffering less damage.
3. Prevention and control methods for daylily rust:
1. Strengthen fertilizer and water management to enhance plant resistance (refer to the cultivation practices for preventing daylily anthracnose).
2. Spray pesticides early to prevent and control the disease. During the local season when the disease occurs and spreads, strengthen inspections. Once scattered initially diseased plants are found, in addition to pruning diseased leaves or cutting down and burning diseased plants, pesticides should be sprayed to contain the disease center and eliminate the disease at the spotted and patchy stage. For pesticide use, refer to the prevention and control of asparagus rust and the prevention and control of goji powdery mildew.
Cultivated Varieties of Daylily
1. Early-maturing type: Early-maturing daylily varieties include Siyuehua, Wuyuehua, Qingzaohua, Zaochashantiaozihua, and others.
2. Mid-maturing type: Mid-maturing daylily varieties include Aijianzhongqihua, Gaojianzhongqihua, Mengzihua, Baihua, Qiezihua, Chazihua, Changbahua, Heizuihua, and others.
3. Late-maturing type: Late-maturing daylily varieties include Daojianhua, Xiyezihua, Zhongqiuhua, Dayezihua, and others.
In the process of growing daylilies, in addition to mastering certain cultivation techniques, the most important thing is to have an understanding of the prevention and treatment of their diseases. Only by understanding the symptoms and treatment methods of some of their common diseases will you not panic when corresponding diseases appear during cultivation.