What to Do About Black Heart and Black Skin in Radishes? A Detailed Guide to the Latest Control Methods
Black heart and black skin in radishes is a common phenomenon in cultivation, seriously affecting the yield and quality of radishes and bringing huge losses to farmers. So what causes black heart and black skin in radishes? How should they be controlled? Follow along with the editor for a detailed look below.
1. Apply sufficient boron fertilizer
The main cause of black heart and black skin in radishes is boron deficiency. To prevent black heart and black skin caused by boron deficiency, the first step is to apply sufficient basal fertilizer. Organic fertilizer not only has complete nutrients but also has a high boron content. It can greatly improve soil structure and physical and chemical properties, enhance the soil's water- and fertilizer-holding capacity, expand the range of root extension, reduce drought damage, and promote the absorption of boron and other nutrients by vegetable crops. Organic fertilizer can be used as basal fertilizer or topdressing. The basal fertilizer rate is generally 4000-6000 kg per mu. For topdressing, it is 1000-2000 kg. In plots with severe boron deficiency, 300-400 g of borax per mu can also be applied. When topdressing, it can be mixed evenly with other fertilizers before application, or foliar spraying can be used, spraying a 0.2% boric acid or 0.3% borax aqueous solution.
2. Break up soil compaction
Soil compaction is an important cause of black heart and black skin in radishes. Hard, compacted soil with poor aeration, combined with the application of undecomposed organic fertilizer, causes intense microbial activity in the soil, consuming too much oxygen and resulting in oxygen deficiency in the roots and some tissues, leading to black skin or black heart. The best measure to break up soil compaction is deep plowing and fine harrowing: first plow 18-20 cm deep, then use a harrow to break up the clods. When water accumulates, it should be drained promptly to avoid soil oxygen deficiency and compaction.
3. Control black rot
When black rot occurs, the leaf veins turn black in a net-like pattern, and eventually the leaves dry up and turn yellow. When the radish fleshy root is infected, a cross-section shows the vascular bundles turning blackish-brown in a radial pattern, and in severe cases they become shriveled and hollow. To control black rot, first choose disease-tolerant varieties, and before sowing, sun the seeds, soak them in warm water, and disinfect them with chemicals. Before summer sowing, the soil can be deep plowed and sunned to eliminate pathogens in the soil, then some quintozene can be scattered and a layer of fine soil applied. Rotating with non-cruciferous vegetables for 2-3 years can effectively control the disease. Strengthen field management, water timely at the seedling stage, carry out reasonable seedling hardening, promptly pull out diseased plants and remove diseased leaves to reduce opportunities for repeated infection by pathogens. In the early stage of disease onset, pesticides such as agricultural streptomycin sulfate, thiodiazole-copper, and oxolinic acid can be sprayed for control.
The above is an introduction to the control methods for black heart and black skin in radishes. We hope it helps you. For more related knowledge, please stay tuned to us.