Resistance of Eight Premium Melon Varieties to Viral Diseases in a Commercial Greenhouse in Central Kalimantan

Melon (Cucumis melo L.) is one of the most important horticultural commodities in Indonesia, especially premium varieties with high market value. However, viral diseases such as Cucumber mosaic virus (CMV), Zucchini yellow mosaic virus (ZYMV), Papaya ringspot virus (PRSV), and Watermelon mosaic virus (WMV) remain a significant constraint, causing mosaic, chlorosis, deformation, and yield reduction. This study aimed to evaluate the resistance of eight premium melon varieties against viral diseases under commercial greenhouse conditions in Palangka Raya, Central Kalimantan. The experiment was conducted in a hydroponic production system under natural infection pressure without artificial inoculation. Disease incidence was visually assessed at both vegetative and reproductive stages, and disease progression was quantified using the Area Under the Disease Progress Curve (AUDPC). Results showed apparent variation among varieties in their response to viral infection. Inthanon exhibited the highest disease incidence (up to 45%) and the highest AUDPC value (12.36), indicating high susceptibility. Kirin and Sweet D25 also displayed relatively high incidence and AUDPC values (7.6–7.7). Conversely, Alisha and Meldo UPNVY No. 1 consistently showed the lowest incidence (<15% and <5%, respectively) and the lowest AUDPC values (0.83 and 3.24), demonstrating strong resistance. The remaining varieties (Apollo, Sweet D25, Meldo UPNVY No. 2, and Sweet Hami) showed intermediate resistance. These findings underscore the significance of varietal selection in the integrated management of viral diseases in melon. Resistant varieties such as Alisha and Meldo UPNVY No. 1 may serve as promising candidates for commercial production and future breeding programs to reduce yield losses and minimize reliance on chemical or vector control strategies.