What are the control methods for black heart and black skin in radishes?
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 to learn more.
1. Apply sufficient boron fertilizer
The main cause of black heart and black skin in radishes is boron deficiency, and to prevent black heart and black skin caused by a lack of boron, the first step is to apply sufficient base fertilizer. Organic fertilizer not only has complete nutrients but also 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 base fertilizer or top dressing. The base fertilizer rate is generally 4000-6000 kg per mu. For top dressing, it is 1000-2000 kg, and in plots with severe boron deficiency, 300-400 g of borax can also be applied per mu. During top dressing, it can be applied after mixing evenly with other fertilizers, or a foliar spray 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. When the soil is hard, compacted, and poorly aerated, and undecomposed organic fertilizer has been applied, microbial activity in the soil becomes intense, consuming too much oxygen, causing oxygen deficiency in the roots and some tissues and resulting in black skin or black heart. The best measure to break up soil compaction is deep plowing and fine harrowing: first plow deeply 18-20 cm, then use a harrow to break the soil up finely. When there is standing water, it should be drained promptly to avoid oxygen deficiency and compaction in the soil.
3. Control black rot
When black rot occurs, the leaf veins turn black and appear net-like, 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 shrunken and hollow. To control black rot, first select disease-tolerant varieties, and before sowing, sun the seeds, soak them in a greenhouse, and disinfect them with chemicals. Before summer sowing, the soil can be deeply plowed and sunned to eliminate pathogenic bacteria in the soil, then some quintozene can be spread and a layer of fine soil covered over it. Rotating for 2-3 years with non-cruciferous vegetables can effectively control the disease. Strengthen field management, water seedlings at the proper time, regulate seedling hardening reasonably, promptly pull out diseased plants and remove diseased leaves to reduce opportunities for repeated infection by pathogens. In the early stage of the disease, chemicals such as agricultural streptomycin sulfate, thiodiazole-copper, and quinoline fungicides 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. To learn more related knowledge, please keep following us.