How to prevent and control pests and diseases of Arisaema? Latest technical methods tutorial

Arisaema, also known as Nanxing, Bai Nanxing, etc., is a perennial herbaceous plant of the genus Arisaema in the Araceae family, mostly wild, and can be cultivated throughout northern and southern China. Except for the northwest and Tibet, it is distributed in most provinces and regions, at altitudes below 2700 m, growing under forest, in thickets or grassland. Now let us take a look at the pest and disease control techniques for Arisaema!

Viral disease

[Damage characteristics] Leaf symptoms often appear as mosaic, irregular chlorosis or yellow streaks, causing the veins to curl longitudinally and become deformed. The diseased plants are stunted, chlorophyll in the leaves is hindered, normal photosynthesis is affected, and tuber yield and quality are affected. It is caused by a variety of viruses. In Arisaema propagated by tubers, the virus can accumulate in the plant body, and some can be transmitted by aphids. When the aphid population in the field is large and the damage lasts a long time, the disease is severe.

[Control methods] (1) Use virus-free technology, planting and propagating with virus-free stock, or propagate with virus-free seeds. (2) Where conditions permit, advocate the use of heat treatment combined with shoot-tip virus elimination to obtain virus-free seedlings. (3) When aphids are found, spray insecticides promptly to kill the aphids and reduce virus transmission.

Anthracnose

[Damage characteristics] Anthracnose is one of the main diseases in Arisaema growing areas, seriously affecting the yield and quality of Arisaema. It mainly damages leaves, petioles, stems and fruits. When leaves are infected, the leaf spots are round or nearly round, 2-5 mm in size, with the center grayish white to light brown and the edge green to brown. Black small dots are arranged in rings or clustered on the diseased part. When stems and petioles are infected, light brown spindle-shaped sunken spots are produced, densely covered with small black granules. When humidity is high, a large number of orange-red conidia gather on the acervuli. When berries are infected, reddish-brown sunken spots also form.

[Agricultural control] Plant at a reasonable density, pay attention to ventilation and air permeability, apply fertilizer with a scientific formula, increase the application of phosphorus and potassium fertilizers to improve plant disease resistance, irrigate at the proper time, strictly prohibit flooding irrigation, drain promptly after rain to prevent excessive humidity, promptly remove infected leaves, and cut off the diseased spots of lightly diseased leaves.

[Chemical control] Before onset, spray 1% Bordeaux mixture or 27% high-fat film emulsion at 100-200 times dilution for protection. During the disease period, choose 75% chlorothalonil at 1000 times dilution, 20% tricyclazole at 800 times dilution, 50% anthracnose Fumei at 600 times dilution, once every 7-10 days, for several consecutive applications. Fungicides should be used in rotation for better results.

Root rot

[Damage characteristics] Root rot usually occurs from May to October. The tubers of affected plants rot, the leaves wither and die, and it spreads very quickly.

[Control methods] Drain accumulated water from the ground during the rainy season. After rain in the hot summer, irrigate promptly with well water to lower the ground temperature. In summer, spray carbendazim at 1000 times dilution for prevention. When diseased plants are found, dig them out promptly and burn them, and disinfect the diseased holes with quicklime.

Stem blight

[Damage characteristics] After the seedlings emerge, a brown ring-shaped depression and constriction occur at the junction between the corm near the ground surface and the young stem below the soil surface at the base. Low temperature and high humidity, and improper crop rotation are the main factors for onset.

[Control methods] Commonly used agents include 70% thiophanate-methyl wettable powder at 500 times dilution and 75% chlorothalonil wettable powder at 500 times dilution, sprayed once every 7-8 days for three consecutive sprays, which can effectively control the disease. In the early stage of onset, spray 75% chlorothalonil wettable powder at 600 times dilution, or 38% oxadixyl-azoxystrobin at 800 times dilution, 64% Sandofan wettable powder at 400 times dilution, or 50% iprodione wettable powder at 1000 times dilution, or 70% ethylicin · mancozeb at 500 times dilution.

Phytophthora blight

[Damage characteristics] Phytophthora blight is a soil-borne disease caused by Phytophthora. The optimum temperature for onset is 20-25 degrees C, and it is especially severe during the rainy season. The affected parts initially appear water-soaked, and the tissue fades and turns brown. In the early stage of infection, the diseased tissue still maintains considerable toughness, and only later does the affected part rot, collapse and disintegrate.

[Agricultural control] (1) The most effective and simplest measure is to strengthen field sanitation management, remove diseased plants, diseased leaves and weeds at any time, and take them out of the plot to burn. Plant residues must not be piled up in the plot, so as to avoid breeding pathogens. Try to avoid rain drenching, watering and splashing. Even after rain drenching, preventive spraying must be done promptly. (2) Strengthen ventilation and cooling in the plot, and nitrogen fertilizer must not be excessive.

[Chemical control] The following can be used in rotation: 58% metalaxyl-mancozeb (mancozeb-metalaxyl) at 400-600 times dilution, 72.2% propamocarb aqueous solution at 800-1000 times dilution, 50% iprodione wettable powder at 1000-1500 times dilution, 64% Sandofan wettable powder at 400-500 times dilution, and 80% mancozeb wettable powder at 400 times dilution.

Red hawk moth

[Damage characteristics] The larvae damage leaves, biting them into notches and holes. When the infestation is severe from July to August, they eat all the Arisaema leaves.

[Control methods] (1) When the larvae are young, spray 90% trichlorfon at 800 times dilution to kill them. (2) Avoid continuous cropping, and also avoid intercropping with plants of the same family such as Pinellia ternata and konjac.