How to Treat Root Rot and Seedling Death in Yardlong Beans? A Full Guide to Prevention and Control Methods

Root rot in yardlong beans is highly damaging to the crop. It can occur from the seedling stage through the harvest period and mainly attacks the roots and stems. When the roots are affected, typical root rot develops: the main and lateral roots and the base of the stem turn brown and rot, and the diseased area is slightly sunken, which can lead to seedling death. So, how do you treat root rot and seedling death in yardlong beans?

I. How to treat root rot and seedling death in yardlong beans?

You can drench the roots with 12.5% enhanced carbendazim soluble concentrate at 200-300 times dilution, 12.5% zhiweiling aqueous solution at 200-300 times dilution, 60% fangmeibao wettable powder at 500-600 times dilution, 50% carbendazim wettable powder at 500 times dilution, 40% kujunling wettable powder at 500-600 times dilution, 70% dexon wettable powder at 800-1000 times dilution, or genbingling at 500-600 times dilution, applying 250 milliliters of solution per plant, then drenching again after 10 days.

II. Other common disease prevention and control methods for yardlong beans

1. Fusarium wilt

Disease characteristics: Fusarium wilt mainly harms the roots, stems and leaves of yardlong beans. In the early stages of infection, the disease begins on the lower part of the plant, and water-soaked patches appear on the leaf margins. The patches gradually expand and spread until eventually the entire leaf merges into one large patch, and the leaf finally withers and dies. Cracks also begin to appear at the base of the stem, and the color gradually darkens. When external humidity is too high, mold spots also appear on the patches.

Prevention and control methods: Do not practice continuous cropping on the same plot; ensure at least two years of rotation, and the rotation crop must not be a legume. Improve the soil, neutralize soil acidity, and reduce the pathogen. After the disease occurs, use carbendazim wettable powder and similar agents for control. The dosage depends on the severity of the disease; apply at least once a week for one month.

2. Viral disease

Disease characteristics: Viral disease mainly harms the leaves of yardlong beans. After the leaves are infected, areas of deeper color appear on parts of the leaf, and the affected areas become uneven and bumpy, then begin to curl. Viral disease delays flowering time, causes uneven flowering, severely reduces pollination and fertilization rates, greatly affects yield, and may even lead to total crop loss.

Prevention and control methods: When selecting varieties, choose disease-free, pest-free varieties with strong disease resistance. Observe frequently during the growing process, strengthen the use of chemical control, and improve the resistance of yardlong beans. Because the main vector is aphids, and aphids not only spread viral disease pathogens but also have a major impact on the crop themselves, we must also pay attention to aphid control. Reduce pathogen spread and lower the incidence of disease.

3. Yardlong bean rust

Disease characteristics: Yardlong bean rust also mainly harms the leaves. When leaves are infected with yardlong bean rust, colored patches appear on the leaves. As time passes, the color gradually deepens, and the affected areas begin to bulge. The bulging areas are the pathogen spores, and after the seed coat surface ruptures, red powder also appears.

Prevention and control methods: After harvesting the first crop of yardlong beans, thoroughly disinfect the field, destroy diseased plant debris, and keep it away from the vegetable garden to avoid further spread. Choose varieties with strong disease resistance and apply appropriate chemical prevention to the plants.

When growing yardlong beans, severe disease can affect yield, so everyone must do a good job of prevention and strengthen field management.