International Journal of Horticulture, 2025, Vol.15, No.2, 61-72 http://hortherbpublisher.com/index.php/ijh 66 Growth direction control and plant training are crucial for maximizing the efficiency of the support system and ensuring that yellow pitaya plants grow in an organized manner. Techniques such as tying the branches to the trellis, using clips or ties, and regularly adjusting the plant's position can help in directing growth (Shah et al., 2023). This practice ensures that the plants grow in a manageable and productive manner, facilitating better light exposure and air circulation. 5.3 Hormone regulation and flowering period management The use of plant growth regulators (PGRs) can significantly enhance the flowering and fruiting of yellow pitaya. PGRs such as auxins, gibberellins, and cytokinins can be applied to stimulate flower bud formation and improve fruit set. These hormones help in synchronizing the flowering period, leading to a more uniform and predictable harvest (Oltehua-Lopez et al., 2023; Erazo-Lara et al., 2024). However, careful management is required when using plant growth regulators (PGRs), as improper application may result in excessive vegetative growth, adversely affecting fruit development. By applying appropriate amounts of growth regulators at the right stages, farmers can ensure an increased number of flowers, thereby enhancing fruit set and ultimately boosting yield. Flowering management is equally important for achieving synchronized fruit production, which simplifies harvest management and improves marketability. Techniques such as adjusting irrigation schedules, applying PGRs, and manipulating light exposure can help in controlling the timing of flowering. For instance, ensuring that the plants receive consistent and adequate water during the flowering period can promote uniform flowering and fruit set (Li et al., 2022). Additionally, hand pollination within a specific time frame after flowering can optimize fruit setting and size. 6 Pest and Disease Control of Yellow Pitaya 6.1 Common diseases and control measures Yellow pitaya (Selenicereus megalanthus) is susceptible to several diseases, including black rot, anthracnose, stem brown spot, and stem canker. Black rot, caused by Alternaria alternata, manifests as dark lesions on the fruit, leading to significant postharvest losses (Vilaplana et al., 2018a; b). Anthracnose, caused by Colletotrichum gloeosporioides, presents as reddish-orange spots that turn dark brown and can lead to significant crop damage (Bello et al., 2022). Stem brown spot, caused by Nigrospora sphaerica, appears as reddish-brown necrotic lesions on the stems, which can merge into larger dark brown areas (Khoo et al., 2022a). Stem canker, caused by Neoscytalidium dimidiatum, is characterized by black pycnidia on the stem surface, leading to rotting and significant plant damage (Khoo et al., 2022b). Effective control of these diseases involves both chemical and non-chemical methods. Sodium bicarbonate (SBC) treatments have shown efficacy in controlling black rot, reducing weight loss, and maintaining fruit quality during storage (Vilaplana et al., 2018a). Hot water treatments at 50 °C for 2 minutes have also been effective in reducing black rot lesions without affecting fruit quality (Vilaplana et al., 2018b). For anthracnose, biological fungicides like Serenade ASO, containing Bacillus amyloliquefaciens, have demonstrated complete inhibition of the pathogen's mycelial growth (Bello et al., 2022). Regular monitoring and early detection are crucial for managing stem brown spot and stem canker, with molecular and morphological characterization aiding in accurate pathogen identification (Khoo et al., 2022a;b). 6.2 Types of pests and integrated control strategies Yellow pitaya is affected by various pests, including the guava root-knot nematode (Meloidogyne enterolobii) and fruit flies like Bactrocera correcta. The guava root-knot nematode causes plant stunting, reduced yields, and galled roots, significantly impacting plant health and productivity (Wu et al., 2023). Bactrocera correcta, a significant pest of pitaya, affects the fruit quality and yield, with the 3rd instar larvae being the most tolerant to control measures (Shan et al., 2023). Integrated Pest Management (IPM) for yellow pitaya involves a combination of chemical, biological, and cultural practices. For nematode control, regular soil health monitoring and the use of resistant plant varieties are
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