Common diseases of yellowhorn (Xanthoceras sorbifolium) and the latest control methods
Yellowhorn (Xanthoceras sorbifolium) is now one of the most important oil crops in our country. Its seeds and seed kernels contain a very large amount of oil, and it is very easy to grow. It has no particularly strict requirements for basic conditions such as the growing environment and soil, and its disease resistance is also relatively strong, although its incidence rate is relatively low. However, if it is not managed well, some diseases will still occur. So what diseases can occur in yellowhorn trees? How should they be controlled? Let's take a look below!
1. Yellowhorn root rot nematode disease
Symptoms: Root rot nematode disease is caused by nematodes parasitizing the root and stem parts. It mainly harms seedlings and young trees, and generally begins to occur after the seedlings emerge during sowing and seedling raising. Nematodes in the soil and residual roots invade, mainly under damp and shady conditions. The leaves will all turn yellow and withered, but they will not fall off for a long time. The aboveground part shrinks and stops growing, and later gradually dies. After pulling out the diseased seedling, you will find a swollen state below the root crown, yellow water-soaked, and accompanied by a foul odor.
Control methods: In the relatively damp and shady seasons of autumn and winter, the seedling field should be plowed and earthed up to reduce the incidence of disease. When sowing, the seeds must not be buried too deep, and the bottom water should be watered sufficiently to avoid nematodes spreading through water due to insufficient water later. During the emergence stage, cultivating and earthed-up soil should be strengthened. If any abnormal damage is found, the diseased plants must be removed and disposed of in time. When pests are found, pesticides such as ethoprophos or fosthiazate can be sprayed for control.
2. Yellowhorn stem rot
Symptoms: Stem rot is a disease that occurs in most plants. It is mainly a fungal disease caused by Fusarium and Verticillium. The pathogen overwinters in the soil and has extremely strong saprophytic ability. It is most likely to occur in waterlogged environments with excessively high temperatures, and generally begins to occur two months after planting. It mainly harms the underground roots. The roots produce rotten dark brown sclerotia, which then begin to extend and spread around the stem base, causing the cortex to gradually rot. The leaves also begin to turn yellow and wilt, and finally the whole plant dies directly.
Control methods: Stem rot is mainly infected through root wounds, so during transportation and planting, damage should be avoided to prevent mechanical injury that gives the pathogen an opportunity. After lifting the seedlings, try to soak them in a solution such as potassium permanganate to reduce pathogen infection of the seedlings. During high temperature and hot weather, do a good job of cooling and shading, and use decomposed farmyard manure. Control the planting density well, maintain the humidity in the soil, and reduce the incidence rate. You can also spray some pesticides such as oxadixyl on the affected ground for control to prevent pathogen invasion.
3. Yellowhorn sooty mold
Symptoms: Sooty mold is mainly caused by psyllids sucking the sap of tender tissues. It often occurs on leaves and occasionally appears on tender shoots. Small black spots appear on the leaves, then gradually expand and extend until all the small spots combine together, and the entire leaf is covered with a black mold layer. When tender shoots are affected, it is almost the same as on the leaves. In severe cases, the whole tree will become charcoal black.
Control methods: During daily management of yellowhorn in the cultivation process, the planting density of yellowhorn should be controlled well, and the tree body should be pruned appropriately. Improve the permeability in the orchard and reduce the humidity in the orchard. Spraying can be used to control insects such as psyllids and aphids to prevent virus transmission. During the dormant period of the tree body in winter and when it is about to sprout in spring, some lime sulfur mixture can be sprayed on the tree crown to eliminate overwintering sources of disease.
The above three are relatively common diseases when planting yellowhorn. Although there are more than these three, these three are the most representative. Therefore, everyone must pay attention to orchard management, disinfect the soil during overwintering, centrally clean up diseased and disabled branches, and treat affected tree bodies according to the symptoms. If there is no effect, they should be pulled out in time to prevent contagion. This article is for reference only, and we hope it is helpful to everyone!