Prevention and control of diseases and insect pests of Luoshen flower: Fusarium wilt of Luoshen flower is easy to appear, and there are four major methods to strengthen prevention and control in rainy season.

Taitung is the main producing area of Luoshen flower in China. According to the investigation of field diseases and insect pests in Taitung Agricultural improvement Farm of Taitung District in recent years, wilt often occurs in Taitung Luoshen flower field, and the incidence of disease in some areas is even more than 80%, causing serious losses to farmers. In order to avoid the spread of the disease, Taitung Field called on farmers to step up inspection of the fields and adopt appropriate prevention and control measures to reduce damage.

The agricultural reform farm in Taitung District pointed out that the Luoshen flower wilt is caused by plant pathogenic fungi or oomycetes. Once the Luoshen flower wilt occurs, the leaves will droop under the water, and the stems near the ground will be browned. In the later stage of the wilt, the roots of Luoshen flowers will brown and rot, and the whole plant will be dry and withered. Luoshen flower wilt mostly appears symptoms after the rainy season, and often spreads rapidly after occurrence, and there is no time for pesticide control. Because the pathogen of Fusarium wilt has the property of soil transmission, continuous planting or poor drainage is more likely to occur.

Most of the diseased plants have been pulled out and discarded in the ridges of the fields where the disease is seriously affected. It is best to move out of the field and do not continue cropping in the next stage.

Taitung Field advises farmers to avoid continuous cropping, make beds and strengthen drainage, apply phosphorous acid before the rainy season or when there are only sporadic diseased plants, and use chemicals in the event of wilt.

1. Avoid continuous cropping: in the case of continuous planting of the same crop, the pathogenic bacteria are easy to accumulate, which makes the disease more serious. It is suggested that Luoshenhua can be rotated with millet, quinoa or tree bean to reduce the density of pathogens in the soil.

2. Make beds and strengthen drainage: stagnant water in the fields will accelerate the spread and infection of diseases. It is recommended that the fields with poor drainage should level the land and make beds before planting Luoshenhua to strengthen drainage.

3. Application of phosphorous acid prevention: phosphorous acid can stimulate plants to enhance disease resistance, but the effect of application after disease is not obvious, so it is recommended to spray the whole plant with phosphite 500 × 1000 times diluent before the rainy season or when sporadic diseased plants appear. Once every 7 days, 2 or 3 times in a row to prevent. Should pay special attention to that phosphite (H3PO3) is a strong acid, which must be neutralized with potassium hydroxide (KOH) at 1:1 and then mixed; or dissolve phosphite first and then slowly add potassium hydroxide, both of which should not be added to the water at the same time to avoid the risk of high heat.

4. Chemical control: refer to the recommended use of Luoshen flower blight in the plant protection manual, such as 525 g Damidodine water suspension, 60.8% flurbibach water suspension, 60% anti-Kemin water dispersible granules, 85% alkaline copper oxychloride wettable powder, etc., starting at the initial stage of the occurrence of Fusarium wilt, once every 7 days if necessary.

The agricultural reform farm in Taitung District points out that in recent years, wilt has seriously affected Luoshenhua in Taitung, reminding farmers that they must do a good job in disease management to ensure the harvest. If you have any questions on prevention and control, farmers can contact Taitung Plant Protection Research Room (Tel. 089-325015).