Because the cauliflower planting season coincides with the hot and rainy summer, it is very easy to cause the occurrence of diseases and insect pests, which seriously makes the vegetable growers lose their money. At present, there are more than 40 kinds of cauliflower diseases and insect pests discovered in China, of which more than 20 kinds of diseases, mainly black rot, downy mildew, black spot, etc.; there are more than 10 physiological diseases, mainly including early spot balls and curd Pod leaves, hairy flowers, etc. The perennial losses caused by the occurrence of pests and diseases amount to 20%~50%.
The following is a brief introduction to the most common diseases of cauliflower, so that the majority of vegetable farmers and distributors will be prepared and have a good harvest.
1. Cauliflower damping-off
[Symptoms] After the seed germinates to before unearthed, it becomes rotten seeds; after unearthed, it becomes water-stained, softened, and the epidermis falls off near the soil surface. The diseased part constricts and rapidly expands around the stem. Caused a piece of dead seedlings.
1. Select disease-resistant varieties; encourage the application of compost made of enzyme bacteria and fully decomposed organic fertilizer; implement crop rotation, use ridge or deep furrow planting in wetlands, and plant reasonably densely to prevent excessive surface humidity and timely drainage after rain.
2. Seed treatment: dress seeds with 75% chlorothalonil wettable powder of 0.2%-0.3% of seed weight, or 70% mancozeb dry suspending agent.
3. Available at the initial stage of the disease: 40% aluminum triethylphosphonate wettable powder 200 times liquid, or 70% ethyl phosphorus and manganese zinc wettable powder 500 times liquid, or 58% metalaxyl. Manganese zinc wettable powder 500 times liquid , Once every 10 days or so, continuous control 2-3 times, and spray enough to spray evenly.
2. Cauliflower Downy Mildew
[Symptoms] Mainly damage leaves. It usually occurs on the lower leaves of the plant, and yellow spots appear. The edges of the lesions are not obvious under humid conditions, but are obvious under dry conditions. The lesions are also polygonal or irregular due to the limitation of leaf veins. When the humidity is high, sparse white mold can be seen on the back of the lesion. When the disease is severe, the diseased spots are continuous, causing the leaves to wither and die.
1. Choose disease-resistant varieties; avoid continuous cropping with cruciferous vegetables; deep soil in the sun, deep furrows and high borders, timely drainage after rain, prevent flooding, and minimize field humidity.
2. Seed treatment: dress seeds with 35% metalaxyl wettable powder or 50% thiram wettable powder with 0.3% of seed weight.
3. In the early stage of the disease, use 68% metalaxyl. Manganese zinc water dispersible granules 588-770 times liquid, or 58% metalaxyl. Manganese zinc wettable powder 800 times liquid, or 72% cymoxanil. Manganese zinc wettability Powder 800 times liquid, spray once every 7-10 days, 2-3 times in a row, spraying is prohibited 15 days before harvest.
Three, cauliflower black rot
[Symptoms] Mainly damage leaves, flower bulbs or stems. In the seedling stage, the cotyledons are infected in a water-soaked state, and then die quickly or spread to the true leaves, causing the leaf veins to show small streaks of varying lengths. In the adult stage, the true leaves are infected, causing the leaf margins to show "V"-shaped strips, and the bacteria spread down along the veins to form larger necrotic areas or irregular yellow-brown spots. In severe cases, it may cause complete wither or partial rot of outer leaves. When the weather is dry, the diseased spots are dry or perforated.
1. Select disease-resistant varieties and rotate them with non-cruciferous vegetables for more than 2 years; drain water in time after rain, and fertilize them reasonably; remove diseased plants in the field in time.
2. Seed treatment: before sowing the seeds in the sun for 2 to 3 hours, then soak the seeds in 50 ℃ warm water for 12 hours, or dress the seeds with 0.3% of the seed weight of 50% thiram WP.
3. In the early stage of the disease, the following fungicides can be used for prevention and control: 72% agricultural streptomycin sulfate soluble powder 3000-4000 times liquid, or 2% kasugamycin wettable powder 300-500 times liquid, or 20% ecumazole wettability Powder 600-800 times liquid, or 36% trichloroisocyanuric acid wettable powder 1000-1500 times liquid, spray on water, spray once every 7-10 days depending on the condition.
4. Cauliflower black spot
[Symptoms] Mainly damage leaves. Initially, small black spots are produced on the leaves, and after expansion, they become gray-brown round spots with inconspicuous ring patterns. When the humidity is high, more black mold will be produced on the lesions. When the disease is severe, the leaves are covered with diseased spots, and sometimes the diseased spots merge into large spots, causing the leaves to turn yellow and wither early. Stems and petioles can also be affected. The diseased spots are dark brown, long strips, and have a black mold layer.
1. Rotate with non-cruciferous vegetables every other year; remove diseased bodies in the field in time; carry out deep ploughing and sun drying of the soil, and timely drainage after rain.
2. Seed treatment: Soak the seeds in 50℃ warm water for 20-30 minutes, then immediately transfer them into cold water to cool down, then sow after sun-dried, or dress the seeds with 0.2%-0.3% Iprodione by weight of the seeds.
3. At the early stage of the disease, spray 50% Iprodione WP 1200 times, 64% frost. Manganese zinc WP 500-700 times, or use 75% Chlorothalonil WP 600 times for prevention and treatment. Spray once every 10-15 days, 1-3 times in a row.
5. Cauliflower virus disease
[Symptoms] Mainly damage the leaves. At the initial stage, round and small chlorotic spots are formed on the leaves. Later, the color of the whole leaves becomes lighter, or there are shades of green mottle. With the development of the disease, the leaves shrink, twist, deform, and the veins on the back of the leaves develop. Verrucous protrusions, dwarfing of diseased plants is not obvious.
1. Select disease-resistant varieties and rotate crops reasonably; increase organic fertilizer, water frequently in hot and dry seasons and control aphids; spray compound foliar fertilizer to control disease and enhance plant disease resistance.
2. In the early stage of the disease, the following agents can be used for prevention and treatment: 0.5% mushroom proteoglycan liquid 250-300 times liquid, or 25% morpholinoguanidine hydrochloride. Zinc soluble powder 500 times liquid, or 2% Ningnanmycin liquid 500 times liquid.
6. Cauliflower Sclerotinia sclerotiorum
[Symptoms] Mainly damage the base of the stem, the leaves and the flower bulbs, the initial water-stained light brown irregular lesions, slowly soft rot, forming white or off-white cotton-like mycelium, and the formation of black rat fecal sclerotia, to the stem One week after the basal diseased ring stem, the whole plant died. The disease occurs on the leaves or petioles at the base of the stem and spreads to the stem. The diseased spots on the stem turn from brown to white or off-white. The cortex of the diseased stem is rotted. After the dry, the surface of the diseased tissue is broken and the fibers are in a messy shape. The stem is hollow and white hyphae grow out. Mixed with black sclerotia.
1. High-border planting, reasonable dense planting, good field drainage ditch, lower field temperature, reasonable application of nitrogen fertilizer, increase application of phosphorus and potassium fertilizer; before planting, adjust the bed temperature to 55℃ for 2 hours, which can effectively kill the sclerotia in the soil.
2. Seed treatment: Use 10% salt water or 10%-20% ammonium bisulfate solution to bleach the seeds to remove sclerotia and impurities floating on the water surface. Repeat 2-3 times before sowing.
3. In the early stage of the disease, use 50% Iprodione wettable powder 1000 times liquid, or 50% Thiophanate methyl wettable powder 1000 times liquid, or 50% Procymidone wettable powder 1000 times liquid spray for prevention and control, separated by 7 Spray once every -10 days, 2-3 times in a row, and increase 1-2 times in severely ill fields.
7. Cauliflower soft rot
[Symptoms] The affected part is first infiltrated and translucent, and then the diseased part becomes brown, soft and rot, producing white pus, sticky and slippery in contact with a foul smell. At the beginning of the disease, the diseased plants wilt in the sun and will recover sooner or later. After a period of development, the plant rotted and died.
1. Select disease-resistant varieties; rotate with non-cruciferous vegetables for 2-3 years; select plots with high dryness and good drainage, and use deep furrows and high borders for cultivation; flood irrigation is forbidden, and timely drainage after rain; intertillage loosening soil Weeding should not be too deep, and field farming operations should try to avoid wounds.
2. Seed treatment: Soak the seeds in warm water at 50℃ for 20 minutes; or soak the seeds with 72% agricultural streptomycin sulfate wettable powder 1000 times solution for 2 hours, and then sown after a little drying.
3. At the initial stage of the disease, 3500 times liquid of 72% agricultural streptomycin sulfate wettable powder, or 500 times liquid of 20% Thiophene copper suspension, or 800-1000 times liquid of 50% metasenium water can be used to irrigate or spray. Shower.
8. Cauliflower gray mold
[Symptoms] The seedlings are water-stained and rotted when the disease occurs in the seedling stage, and a gray mildew layer grows on them. Infected plants of adult plants usually start from the leaves closer to the ground, and they are water-stained at first. When the humidity is high, the diseased area rapidly expands, ranging from brown to reddish brown. After the base of the diseased plant stems rot, the upper stems and leaves are withered, and It expands from bottom to top, or extends from the outer leaf to the inner leaf, causing the heading leaf to rot, and small sclerotia are often produced on it. It is easy to be infected during the storage period, causing water-stained soft rot, and gray mold is spread all over the diseased part.
1. Strengthen the management of protected areas or open fields, pay close attention to the temperature in the shed, and reduce the humidity in the shed and the ground in time.
2. In the early stage of the disease, the following agents can be used for prevention: 40% pyrimethanil suspension 600-1000 times liquid, or 45% iprodione suspension 1000 times liquid, or 80% procymidone WP 1000-2000 times liquid .
Nine. Cauliflower root swelling
[Symptoms] The main roots and lateral roots form tumors of varying numbers and sizes. The initial surface is smooth, gradually rough and cracked, and the tumor rots and smells due to the mixture of other bacteria. The diseased plants are obviously short, and the leaves gradually become yellow and wilted from bottom to top, and can recover at night, and gradually develop into permanent wilting, causing the plant to die.
1. Carry out crop rotation with non-cruciferous vegetables for more than 3 years. When cropping with rice, pay attention to increasing the border surface; remove diseased roots thoroughly and destroy them when harvesting; plant in high borders or ridges; acid soil should be appropriately limed to adjust the soil pH to Slightly alkaline; if diseased plants are found, remove them in time, and irrigate the diseased caves with 15% lime water.
2. Use 2-3 kilograms of 70% pentachloronitrobenzene wettable powder per mu, add 50 kilograms of fine soil to mix into medicinal soil, and apply in furrow or hole before planting.
3. In the early stage of the disease, you can irrigate roots with 70% pentachloronitrobenzene wettable powder 800 times liquid, or 50% thiophanate WP 500 times liquid, or 50% carbendazim WP 500 times liquid, for each plant 300 ml of liquid medicine.
10. Cauliflower black root disease
[Symptoms] Mainly damage the roots and stems of plants, making the diseased parts black. Some plants have constricted diseased parts, and white mold can be seen on them when they are wet. At the adult stage, the roots, stems and petioles rot, brown, and form root decay or fall off. The plants wilt and die after dehydration. When the leaves are onset, the lower leaves are first, and "V"-shaped necrotic brown spots are formed on the leaves along the edge of the leaf. In severe cases, irregular brown necrotic spots are scattered on the leaves, and the leaves rot.
1. For spring cultivation, it is advisable to choose varieties that are not sensitive to low temperature in the early growth period, and sow in the right time, not too early or too late.
2. Seed treatment: dress seeds with 75% chlorothalonil wettable powder with 0.3% of seed weight.
3. In the early stage of the disease, it can be used: 1500 times solution of 5% Jinggangmycin solution, or 800 times solution of 72.2% propamocarb hydrochloride salt solution + 800 times solution of 50% thiram WP for spray control, the dosage per mu is 3 liters .
11. Cauliflower Black Shank
[Symptoms] When the disease occurs at the seedling stage, white round or oval lesions are formed on the cotyledons, true leaves and young stems, and there are many small black spots on the lesions. The base of the stem is ulcerated, and the diseased plants are easily broken and dry, causing serious diseased seedlings to die. Adult plants develop disease, irregular to polygonal lesions on the leaves, gray-white in the middle, and many small black spots on the lesions.
1. Carry out crop rotation with non-cruciferous vegetables for more than 3 years; use pathogen-free soil to grow seedlings; remove diseased seedlings when planting; adopt high-border cultivation to facilitate drainage and prevent root damage during farming.
2. Seed treatment: Soak the seeds in warm water at 50°C for 20 minutes, and then sow the seeds after cooling in cold water. Seed dressing with 50% thiophanate-methyl wettable powder with 0.4% of seed quality, or 50% thiram WP.
3. In the early stage of the disease, available: 70% thiophanate methyl WP 1000 times liquid, or 50% carbendazim WP 500 times liquid, or 75% chlorothalonil WP 600 times liquid, or 40% Multi-sulfur suspension agent 600 times liquid for prevention and control. Spray once every 8-10 days, and spray twice.