What are the techniques for off-season fava bean cultivation and pest and disease control?
Fava bean, also known as luohan bean, hu bean, orchid bean, nan bean, shu bean, and fo bean, belongs to the Fabaceae family and the Vicia genus. It is an annual herb, 30-100 (120) cm tall. So what are the techniques for off-season fava bean cultivation and pest and disease control? Let's find out below.
What are the techniques for off-season fava bean cultivation?
1. Site selection
Choose a suitable planting area in the 2000 m elevation planting zone of Midu, where it can generally grow in all four seasons, but if spring fava beans are sown too early, diseases are severe, and flowering and pod setting coincide with the heavy frost period, making them susceptible to frost damage. Off-season fava beans cannot be planted in the flat basin area; they should be planted in cool mountainous areas. On mountain ravine slopes at 2200-2500 m elevation, they generally grow and set seed well.
2. Suitable improved varieties
Select Fengdou No. 6, bred by the Dali Prefecture Agricultural Science Institute. This variety is Fengdou No. 1 X82-2, with a compact plant type, strong disease resistance, and good adaptability.
3. Sowing period
Sow off-season fava beans from June 15 to 25. In the fixed-point observation field, sowing was on June 19, flowering on August 13, 55 days from sowing to flowering, and green fava beans were harvested on September 25, with a growth period of 98 days.
4. Sowing specifications
Use red soil, medium fertility, with corn as the previous crop. Row spacing 24.5 * 10.5 cm, with 25,000 basic seedlings per mu.
5. Fertilizer application
Apply fertilizer concentrated once as a base fertilizer, with 40 kg per mu of compound fertilizer N, P, K. Spray foliar fertilizer “Sihaifeng” once each at the seedling stage and flowering stage, with 300 g per mu each time, diluted 250-300 times with water. Spray 1:500 organic potassium fertilizer once each at the early flowering stage and early pod stage.
6. Strengthen management
Mountainous land has no irrigation conditions and relies on natural rainfall. Pest and disease control should focus on leafminers, rust, chocolate spot, aphids, and rodent and weed damage. Spray mancozeb and carbendazim once each at the seedling stage, spray carbendazim twice and triadimefon twice at the budding and flowering stage, and control aphids twice at the early pod stage.
What are the techniques for fava bean pest and disease control?
1. Fava bean damping-off
Damage characteristics: Fava beans can develop the disease at all growth stages, but it is more severe at the tender pod stage. It mainly infects the stem base or underground parts of fava beans and also damages seeds. When the stem base is infected, black lesions often appear on one side of the stem or around the stem, causing the stem to turn black.
Control method: At the early stage of disease, spray 58% metalaxyl-mancozeb wettable powder 500 solution, or 75% chlorothalonil wettable powder 600-700 solution, or 21% imibenconazole-carbendazim wettable powder 800-1000 times solution, or 20% tolclofos-methyl emulsifiable concentrate 1100-1200 solution, etc.
2. Fava bean chocolate spot
Damage characteristics: Small red spots first appear on the leaves, then gradually expand into round or oval lesions. In severe cases, all parts turn black and wither, and black sclerotia form on the inner wall of the stems.
Control method: At the early stage of disease, spray Bordeaux mixture at 1:2:100. After that, spray 50% carbendazim 500 times solution once every 10 days, for 2-3 consecutive sprays. Spraying Bordeaux mixture at the early stage is better than spraying carbendazim.
3. Fava bean rust
Damage characteristics: Rust spots appear on the leaves until the leaves dry up. In severe cases, the entire plant dies.
Control method: Use 15% triadimefon 50 g mixed with 50-60 kg water for spraying, with 40-60 kg of spray solution per mu. About 20 days after application, spray once more.
4. Fava bean Fusarium wilt
Damage characteristics: Fusarium wilt mainly causes the roots to turn black, with a short and small main root, few lateral roots, yellowing leaves, a wilting plant appearance, and drooping top stems and leaves.
Control method: At the early stage of disease, pour 50% thiophanate-methyl 500 times solution on the roots, applying 2-3 times, which gives good control results.
5. Fava bean brown spot
Damage characteristics: Fava bean brown spot can infect the stems, leaves, pods, and seeds of fava beans. Infected leaves initially show reddish-brown small freckles, which later expand into round or oval lesions. The center of the lesion is light gray, and the edges are dark brown and red, with a diameter of 3-8 mm, densely covered with small black dots arranged in concentric rings. In severe cases, they merge with each other into irregular large patches.
Control method: At the early stage of disease, spray 70% thiophanate-methyl wettable powder 600-800 times solution, or 50% copper bis(dodecylbenzenesulfonate) wettable powder 500-600 solution, etc., once every 7-10 days, for 1-2 consecutive sprays.
6. Fava bean Verticillium wilt
Damage characteristics: Initially yellowing occurs only on one section of the plant, while the other side remains normal in color. The leaves on the upper part of the stem gradually yellow from the lower part upward. The yellowing leaves first appear pale green or greenish-yellow, then completely turn yellow.
Control method: (1) Select disease-resistant varieties and practice crop rotation. (2) At the early stage of disease, irrigate with 50% thiophanate-methyl suspension concentrate 500-600 times solution, or 50% carbendazim wettable powder 500 times solution, or 50% copper bis(dodecylbenzenesulfonate) wettable powder 350 times solution, pouring 500 ml of the prepared solution per plant. Stop applying the pesticide 3 days before harvest.
7. Fava bean anthracnose
Damage characteristics: Fava bean anthracnose mainly damages leaves, stems, and pods. At the early stage of leaf damage, dark reddish-brown small spots are scattered on the surface, then expand into lesions 1-3 mm in size with a light brown center and reddish-brown edges. After the lesions merge, they form large patches, about 10 mm in size. The lesions are round to irregular, mostly limited by leaf veins. Diseased leaves rarely dry up. Later, black small dots form on the lesions.
Control method: Before disease onset or at the early stage of disease, spray 80% carbendazim-thiram wettable powder 800-1000 times solution, or 58% metalaxyl-mancozeb wettable powder 800-1200 times solution, etc. Spray once every 7-10 days, for 2-3 consecutive sprays. Stop applying the pesticide 3 days before harvest.
8. Fava bean mosaic virus
Damage characteristics: Fava bean mosaic virus affects the whole plant. In production, symptoms differ due to different strains of bean yellow mosaic virus, and there are two types: mosaic type and yellowing type. Mosaic-type diseased plants are noticeably dwarfed, with wrinkled, curled, and thickened leaves. The leaf mesophyll is yellow-green alternating in a mosaic mottled pattern. Mildly diseased plants are not obviously stunted, but the top heart leaves often turn yellow or curl. Severely diseased plants are noticeably smaller than healthy plants and do not flower or set seed. Yellowing-type plants are short, with yellow and thin leaves and upright stems, generally without wilting, and diseased leaves tend to fall early in the later stage.
Control method: (1) Select disease-resistant varieties and pay attention to strengthening field management. (2) Spray pesticides in time to control aphids; 50% pirimicarb wettable powder 2500-3000 times solution can be used. Stop applying the pesticide three days before harvest.