Detailed Explanation of the Latest Control Measures for Yam Root Rot
Yam is a vegetable that combines edible and medicinal health value, and is deeply loved by consumers. Many people refine eating it, so its market demand is large, and there are also very many people who grow it. However, in the process of yam cultivation, root rot is a disease that seriously affects the yield and quality of yam, bringing a huge impact to growers. So how should yam root rot be controlled? Let's learn about it together.
I. Symptoms of Root Rot
Yam root rot mainly damages the underground stem tubers of yam. When the underground stem tubers are damaged, water-soaked small spots or yellowish-brown necrotic spots first appear, gradually developing into dark brown lesions. In hot and rainy seasons it develops rapidly, and sometimes the diseased part produces white or pink mold-like substances, namely the pathogen's conidia. After the plant is infected, the leaf color is abnormal, the leaves fade green or the leaf margins become necrotic, ultimately leading to the death of the plant. After infection with the pathogen, yam is also extremely prone to rotting during storage, often bringing huge losses to growers.
II. Causes of Occurrence
There are many causes of yam root rot. For example, excessive planting density and too-small plant and row spacing mean that in July-August, when stems and leaves are lush, air permeability is poor, and disease is extremely likely to occur when humidity is relatively high. Or continuous cropping, where soil pathogens accumulate in relatively large amounts, or where root-knot nematodes occur relatively severely, can also induce root rot. When applying fertilizer, if undecomposed farmyard manure or organic fertilizer is applied, the pathogens carried in the fertilizer enter the field, and root rot can also occur. Or if heavy clay soil is selected for planting, with poor air and water permeability, infection is also extremely likely. In July-August, rainfall is relatively heavy. When planting in low-lying plots prone to water accumulation or with poor drainage, humidity is relatively high, and disease is also likely.
III. Control Measures
Pay attention to crop rotation: rotate once every 3 years with crops such as corn, wheat, radish, and watermelon. When planting, choose high-lying, low-humidity, fertile and loose soil for sowing. When preparing the land in autumn, plow diseased residues into the soil, and after winter freezing and spring sun exposure, kill the pathogenic bacteria. At harvest, concentratedly burn diseased residues, weeds, and rotted stems, or take them out of the field for deep burial, to reduce the base number of pathogens in the field. During the rainy season, pay attention to drainage, reduce field humidity, increase the application of decomposed organic fertilizer, increase soil looseness and permeability, and reduce disease occurrence. In the early stage of disease, root irrigation treatment can be carried out with agents such as 30% metalaxyl · hymexazol aqueous solution (Ruimiaoqing), 50% carbendazim · thiram 1000-fold solution, and 58% metalaxyl · mancozeb 600-700-fold solution.
The above is an introduction to the control measures for yam root rot. We hope it can help you. If you want to learn more related knowledge, please follow us.