Symptom identification and control of cauliflower gangrene

Day lily (scientific name: Hemerocallis citrina Baroni), also known as golden needles, lemon day lilies, belongs to Liliaceae, Liliaceae perennial herbs, roots nearly fleshy, the middle and lower parts often have fusiform expansion. Cauliflower has a sweet and cool taste, which has the effects of hemostasis, anti-inflammation, heat-clearing, dampness, digestion, eyesight, calming and so on. It has curative effect on hematemesis, blood in stool, obstruction of urine, insomnia, milk retention, etc., and can be used as a tonic after disease or postpartum.

Morphological characteristics of cauliflower

Hemerocallis foliata perennial herb, 30cm to 65cm tall. The root is fascicled, fleshy, the root tip expands into a spindle shape. Leaves basal, narrowly banded, lower end overlapping, spreading upward, ca. 40 × 60 cm long, 2 cm ~ 4 cm wide, entire, midrib protruding below leaves. Flowering stems drawn from leaf axils, stem apical branches flowering, with several flowers, large, orange-yellow, funnel-shaped, perianth 6-lobed. Capsule, leathery, ellipsoid. The seed is black and bright. The plants are generally tall and large, with fleshy roots and fusiform expansion in the middle and lower parts. Leaves 7-20, 50-130 cm long and 6-25 mm wide.

Scape varies in length, generally slightly longer than leaves, base trigonous, upper ±Terete, branched; bracts lanceolate, lower ones up to 3-10 cm long, shorter from bottom to top, 3-6 mm wide; pedicels shorter, usually less than 1 cm long; flowers many, up to more than 100; perianth yellowish, sometimes blackish purple at the tip of the bud The perianth tube is 3-5 cm long, the perianth lobes are 7-12 cm long, and the inner three segments are 2-3 cm wide. Capsule obtusely trigonous-elliptic, 3-5 cm long. There are more than 20 seeds, black and angled. It takes 40-60 days from flowering to seed maturity. Flowering and fruiting period from May to September.

Symptom identification and control of cauliflower gangrene

The symptom characteristics of cauliflower gangrenous disease:

It mainly harms the leaves and can also harm the flower bolts. Leaf infection mostly starts from the leaf tip or leaf edge, semicircular or oval, brown, the edge is dark brown, the boundary between the disease and the healthy part is clear, and some of the disease spots appear yellow halo. The disease spot expands and joins into stripes, causing the leaves to turn gray-brown to gray-white and dry. In the later stage, there were symptoms of small black spots (conidia disk and conidia).) The pathogen and characteristics of cauliflower gangrenous disease:

The pathogen is the genus Coleophora, including ColletotrichumliliacearumFerr. And C.gloeosporioidesPenz. Both of the two bacteria overwintered with mycelium and conidial disk on diseased plants or in soil with diseased remains. But in the warm south, overwintering is not obvious. The conidia produced on the pathogen's conidia can spread and cause disease by means of wind and rain or the activity of small insects. Warm and humid weather or planting environment is conducive to the disease. Excessive application of nitrogen fertilizer and excessive plant growth are easy to cause the disease. Plots with low-lying dampness, poor drainage or heavy damage caused by spider mites are also prone to disease. There were differences in disease resistance among varieties. Among the 13 varieties of cauliflower introduced in China in recent years (mostly local varieties) Generally speaking, the flowers with strong disease resistance or stress resistance are Jingzhou flower (black mouth flower), Mengzi flower (stick flower, mallet flower), April flower (mango flower) (all local varieties of Shaodong in Hunan), big bird mouth (Jiangsu Huaiyin), green top (Zhejiang Jinyun), Quxian Huanghua (Sichuan), Golden Huanghua (Hubei Tianmen), Shayuan cauliflower (Shaanxi), etc., whether it is also resistant to anthracnose It needs to be further observed and determined in various places. Prevention and control of cauliflower gangrenous disease:

1) selecting disease-resistant varieties according to local conditions.

2) strengthen the management of fertilizer and water. Foliar fertilizer should be sprayed at the right time, especially spring seedling fertilizer, lotus fertilizer, buds fertilizer and winter seedling fertilizer, so that plant nutrition and reproductive growth should be coordinated, strong but not too prosperous, disease resistance should be enhanced, timely and appropriate irrigation, attention should be paid to ditch drainage, and root activity should be improved.

3) early spraying to control the disease. At the latest before the onset of the disease, spray 70% topiramate + 75% chlorothalonil (1:1) 1000ml 1500 times, or 30% copper oxyhydride + 70% mancozeb (1:1) 800ml 1000x, or 50% Baogong wettable powder 1000 times, or 25% carbendazim wettable powder 1000 times, or 80% anthrax Fumei wettable powder 1000 times, 2rel 3 or more, once every 10 times 15 days, apply alternately.