Pest and Disease Control, Nutritional Benefits and Contraindications for Small-Leaf Crown Daisy (Chrysanthemum Greens)
The flowers of small-leaf crown daisy look very much like wild chrysanthemums, which is why it is also known as chrysanthemum greens. It has a long history of cultivation in China and is widely distributed. So do you know how to control pests and diseases during the cultivation of small-leaf crown daisy? What are its benefits and nutritional value? Who should not eat it? According to records in the classics of traditional Chinese medicine, crown daisy can be eaten by the general population. It is suitable for people with high blood pressure, mental workers, people with anemia, patients with fractures, and others. However, because crown daisy is pungent, aromatic and laxative, people with a weak stomach and diarrhea should not eat too much of it.
I. How to control pests and diseases in small-leaf crown daisy
1. Damping-off
Symptoms: It mostly occurs in the middle and late stages of seedling raising. It mainly damages the base of the seedling stem or the underground roots. At first, oval or irregular dark brown lesions appear. In the early stage, diseased seedlings wilt during the day and recover at night. The diseased part gradually sinks and constricts, and some gradually turn dark brown. When the lesions expand and encircle the stem, the plant finally dries up and dies, but does not lodge. Mildly diseased plants only show brown sunken lesions without dying. When the seedbed humidity is high, an indistinct light brown cobweb-like mold can be seen on the diseased part.
Control: In the early stage of the disease, spray 38% oxadixyl-fosetyl-copper 800-fold solution, or 41% polyoxins · pyrimethanil 600-fold solution, or 20% tolclofos-methyl emulsifiable concentrate 1200-fold solution, or 72.2% propamocarb aqueous solution 800-fold solution, once every 7-10 days. Alternatively, dilute General + Menshen at 600-fold, and drench the seedbed with 3 liters per sq m before sowing, after sowing, or before transplanting. At transplanting, after transplanting, or before the expected frequent disease period, dilute this product at 600-fold and drench the roots, applying once every 7 days, with the number of applications depending on the condition of the disease.
2. Leaf spot
Symptoms: Cockscomb leaf spot infects leaves, petioles and stems. The lesions on leaves are round, then expand into irregular large lesions and develop concentric rings. The lesions change from reddish brown to dark brown, with a grayish brown center. The lesions on stems and petioles are brown and elongated. Fish-tail palm leaf spot produces small dark brown round spots on leaves, which later expand or merge into irregular large patches, with slightly raised edges and small black dots scattered on both sides of the leaf. Clivia leaf spot (lesions on leaves are oval or elongated, light reddish brown, surrounded by a chlorotic halo, later expanding into irregular large patches, with black dots produced on the lesions.
Control: In the early stage of the disease, spray 20 ml of 4% pyrimidine nucleoside antibiotics + 20 ml of 41% polyoxins pyrimethanil, mixed with 15 kg of water, applying once every 5-7 days for 2-3 consecutive applications.
3. Sclerotinia rot
Symptoms: It mainly damages stems and vines, leaves and fruits. When the stem base is infected, water-soaked spots first appear, then expand into light brown, causing soft rot or longitudinal cracking of the stem base, and white cottony mycelium grows on the surface of the diseased part. When leaves are infected, gray to grayish brown wet-rot large spots appear on the leaf surface, with the boundary between the lesion edge and healthy tissue not obvious; when humidity is high, flocculent white mold appears on the spot surface, eventually causing the leaves to rot. When fruits are infected, water-soaked spots first appear, and after expansion they become wet-rot, densely covered with white cottony mycelium; in the later stage of the disease, varying numbers of black mouse-dropping-shaped sclerotia appear on the surface of the diseased part.
Control: In the early and middle stages of the disease, use 30 ml of 20% simeconazole prochloraz + 25 ml of oxadixyl kresoxim-methyl, mixed with 15 kg of water, applying once every 5-7 days for 2-3 consecutive applications.
4. Cabbage webworm
Symptoms: Early-instar larvae bore into and feed on the heart leaves of young seedlings of the large cabbage webworm, spin silk and form webs. In mild cases, this affects the growth of the seedlings; in severe cases, it can cause the seedlings to wither and die, resulting in missing plants and broken rows. Older larvae, in addition to gnawing on the heart leaves, can also bore into the stem pith and roots, and can transmit bacterial soft rot, causing the plants to rot and die.
Control: At the peak of larval hatching or when heart leaf damage and silk webs are first seen, apply 5% chlorfluazuron emulsifiable concentrate 4000-fold solution by spraying 2-3 times, taking care to spray the pesticide onto the heart leaves.
5. Aphids
Symptoms: Aphids are pests with piercing-sucking mouthparts. They often gather on leaves, tender stems, flower buds, terminal buds and other parts, piercing and sucking sap, causing leaves to wrinkle, curl and become deformed; in severe cases, they cause branches and leaves to wither and even the whole plant to die.
Control: When the aphid count reaches 500 per 100 plants in the field and the beneficial-to-pest ratio is greater than 1:500, use 50 ml of 25% yamanqing emulsifiable concentrate per mu, or spray a 1500-2000-fold solution of imidacloprid series products, 60-70 g of 10% yashijing, a 2500-fold solution of 20% imidacloprid, or a 3000-fold solution of 25% pirimicarb for control. In wheat regions where wheat aphids have developed resistance to imidacloprid and acetamiprid, the agent should not be used alone; it can be reasonably mixed with low-toxicity organophosphorus pesticides and sprayed.
II. What benefits and nutritional value does small-leaf crown daisy have
Benefits
Crown daisy has effects such as regulating the stomach and strengthening the spleen, lowering blood pressure and tonifying the brain. Eating crown daisy regularly has a relatively good therapeutic effect on cough with profuse phlegm, disharmony between the spleen and stomach, poor memory, and habitual constipation. When crown daisy is stir-fried together with meat, eggs and so on, the absorption rate of vitamin A can be increased. Stir-fry crown daisy briefly, then dress it with sesame oil, monosodium glutamate and refined salt; it is light and pleasant to the taste, and most suitable for patients with coronary heart disease and high blood pressure.
Nutritional value
Every 100 grams contains 95.8 g water, 0.8 g protein, 0.3 g fat, 1.9 g carbohydrates, 0.6 g crude fiber, 0.9 g ash, 0.28 mg carotene, 0.01 mg vitamin B1, 0.03 mg vitamin B2, 0.2 mg nicotinic acid, 2 mg vitamin C, 33 mg calcium, 18 mg phosphorus, 0.8 mg iron, 207 mg potassium, 172 mg sodium, 19.6 mg magnesium, and 240 mg chlorine. It also contains serine, asparagine, threonine, alanine, and others.