International Journal of Horticulture, 2024, Vol.14, No.4, 237-249 http://hortherbpublisher.com/index.php/ijh 246 technical references for the cultivation of thornless yellow dragon. Depending on market demand, appropriate grafting rootstocks can be selected to optimize fruit quality and enhance economic benefits. 4.3 Disease management of thornless yellow dragon 4.3.1 Control of canker disease Similar to red-pulp dragon fruit, thornless yellow dragon is also susceptible to canker disease (Figure 8). Canker disease can cause spots on the stems and fruit surfaces, significantly affecting fruit quality and yield in severe cases (Kazerooni et al., 2020). It is crucial to take effective control measures promptly at the onset of infection. Studies have shown that spraying with a 1,500-fold solution of kasugamycin and quinoline copper and an 800-fold solution of potassium phosphite can effectively control canker disease. The specific method involves spraying twice in succession, with a one-week interval. During the spraying process, the canker spots gradually scab over and fall off, achieving the desired control effect. Figure 8 Branches of thornless yellow dragon infected with canker disease This control method is not only simple and feasible but also offers significant protection for the production of thornless yellow dragon. By implementing scientific disease management, the disease resistance of thornless yellow dragon can be improved, ensuring fruit yield and quality, thereby enhancing market competitiveness. Therefore, effective control of canker disease is an important aspect of the cultivation management of thornless yellow dragon and is worth promoting and applying. 4.3.2 Control of heart rot disease Compared to red-pulp dragon fruit, thornless yellow dragon has a more severe problem with heart rot disease, which manifests as rotting in the center of the fruit (Figure 9). Pathogen isolation tests have revealed that this issue is caused by the infection of Fusariumspp. inside the fruit (Mahmud et al., 2020; Zhao and Huang, 2023). The pistil of thornless yellow dragon is hollow and directly connected to the fruit cavity, allowing pathogens to enter the fruit through the pistil and go dormant (Figure 10). As the sugar content in the fruit accumulates, the internal environment becomes suitable for the proliferation of Fusarium, leading to internal fruit rot. By the 23rd day after flowering, when the fruit enters the color-changing stage, the internal rot begins in the infected fruit, though the surface shows no abnormal signs, making it difficult to distinguish between healthy and diseased fruit by appearance. The incidence of heart rot disease in thornless yellow dragon is higher in summer and lower in winter. Research shows that calcium and magnesium ions play a crucial role in the development of the pistil, promoting rapid expansion of pistil cells, thereby closing the hollow cavity of the pistil and preventing pathogen invasion (Wang et al., 2019). To address the heart rot disease of thornless yellow dragon, we attempted to apply
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