Comprehensive Control Methods and Technical Key Points for Common Bean Viral Diseases
Common bean is cultivated throughout China. It originated in the Americas and is now widely planted in tropical to temperate regions. In China's northwest and northeast regions, it is cultivated in spring and summer; in north China, the Yangtze River basin, and south China, it is spring-sown and autumn-sown. It is suitable for planting in temperate and tropical high-altitude areas, is relatively cold-tolerant and light-loving, belongs to cross-pollinated common bean, a short-day crop. Common bean has a well-developed root system, green leaves, alternate, heart-shaped, flowers are insect-leaf-shaped flowers, racemes, pedicels 15-18 cm long.
Morphological characteristics of common bean
The root system is relatively well-developed. Stems are climbing, semi-climbing, or dwarf. The first true leaves are simple leaves, opposite; later true leaves are trifoliolate compound leaves, nearly heart-shaped. Racemes are axillary, papilionaceous flowers. The corolla is white, yellow, light purple, or purple. Self-pollinating, a few can cross-pollinate. Each inflorescence has several to more than 10 flowers, generally setting 2-6 pods.
Pods are 10-20 cm long, straight or slightly curved in shape, circular or flat-circular in cross-section, epidermis densely covered with pubescence; tender pods are various shades of green, yellow, purple-red (or with markings), etc., turning yellow-white to yellow-brown at maturity. As the pod develops, the vascular bundles at the dorsal and ventral suture lines gradually develop, and the number of sclerenchyma layers in the mesocarp and endocarp gradually increases, thus reducing fresh-eating quality. Therefore, harvesting of tender pods should be done at the right time. Each pod contains 4-8 seeds, seeds are kidney-shaped, with red, white, yellow, black, and mottled colors; 1000-seed weight is 0.3-0.7 kg. Chromosome number 2n=22.
Comprehensive control of common bean viral diseases
Symptoms and transmission routes of common bean viral diseases:
The disease is a systemic symptom, with leaves showing mosaic of dark green and light green, sometimes chlorophyll aggregation visible, forming dark green vein bands and symptoms such as shrinkage and leaf curling. It is mainly caused by infection by Cucumber mosaic virus (CMV), Common bean aphid-transmitted mosaic virus (CoAMV), and Broad bean wilt virus (BBWV). The 3 viruses are mainly transmitted non-persistently in the field by various aphids such as green peach aphid and bean aphid, and can also be transmitted by sap rubbing inoculation of diseased plants and agricultural operations.
Comprehensive control methods for common bean viral diseases:
(1) Select disease-tolerant varieties such as Zhijiang 28-2, Hongzuiyan, etc.
(2) Control aphids early.
(3) Strengthen management and improve disease resistance.
(4) In the early stage of the disease, spray 1.5% Zhibingling II emulsifiable concentrate at 1000 times dilution, or 83 resistance inducer at 100 times dilution, or 20% Kangbingsheng emulsifiable concentrate at 500-800 times dilution, or 60% Virus A tablets (add 2 tablets to 15 kg water), or 20% Wanduqing at 500 times dilution, or 20% Virus A wettable powder at 500-700 times dilution, or 6% Bingduke or 20% Bingdubike wettable powder at 1000 times dilution, or 38% Virus No.1 at 600-800 times dilution, or compound Kebingshen at 500 times dilution plus Zhibaosu at 500 times dilution, or Bingduwang at 500 times dilution plus balancing agent at 300 times dilution, or Bingdu Sukeling emulsifiable concentrate at 500 times dilution plus drought-cold resistance yield-increasing agent (zinc fulvate) at 500 times dilution, spraying once every 7-8 d, 3-4 consecutive sprays.