Yesika Woi, Stanley Adrian F. Walingkas, Stella Tulung, Jantje Pongoh, Antje Grace Tulungen
Upland water spinach (Ipomoea reptans Poir.) is a leafy vegetable with high nutritional value and rapid growth, but its productivity is strongly influenced by light intensity. Water spinach is a plant species characterized by a rapid growth rate, allowing it to be harvested approximately 25 to 30 days after sowing. Light is a crucial factor influencing the rate of photosynthesis in chlorophyll-containing plants and affecting the physiological condition of plant tissues.This study aimed to evaluate the effect of shading levels on seed germination and yield of upland water spinach. The research was conducted from August to September 2025 in Kalasey Satu Village, Minahasa Regency, using a Randomized Block Design with four shading treatments: 0%, 30%, 60%, and 90%. Observed parameters included seed viability and vigor, as well as plant growth and yield components. The results showed that all treatments produced germination percentages above 90%, with the highest viability and vigor obtained under 30% shading. Increased shading promoted plant height but reduced the number of leaves, stem diameter, and fresh weight. The no-shading treatment resulted in the highest yield. Therefore, upland water spinach cultivation is recommended under open-field conditions or light shading up to 30% to achieve optimal growth and maximum yield. Keywords: germination, light, shading, upland water spinach, yield