Greenhouse Management Final Exam 2025/2026 – 50 Q&A on Light, DLI, Photoperiod, PAR & Plant Canopy Dynamics

This exam review document includes 50 high-quality questions and expert-verified answers for the Greenhouse Management final exam, tailored to the 2025/2026 academic year at Albany Technical College and related horticulture programs. It focuses specifically on light management and photobiology in greenhouse production, making it a specialized resource for learners aiming to understand how light quantity, quality, and duration impact plant growth and greenhouse efficiency. Topics include critical light-related metrics such as Photon, Daylight Integral (DLI), Leaf Area Index (LAI), and Photosynthetically Active Radiation (PAR), as well as the roles of short-day and long-day lighting strategies. The guide explains how artificial light sources like LED, HID, fluorescent, and incandescent lights function in greenhouse environments and compares single-leaf versus canopy-level photosynthesis responses. Learners will also explore spectral quality shifts beneath the canopy, interlighting techniques, and the effect of excessive light on temperature and plant stress, especially during high-radiation months. The exam further includes definitions and examples of plant hormones—including auxins, cytokinins, gibberellins, ethylene, abscisic acid, and jasmonic acid—to round out knowledge relevant to plant physiological regulation in controlled environments. This resource is highly recommended for horticulture students, greenhouse management trainees, sustainable agriculture learners, and controlled-environment agriculture professionals preparing for academic exams or real-world greenhouse roles. Keywords: greenhouse light management, DLI, daylight integral, photons, LAI, PAR, short-day lighting, long-day lighting, photoperiod, plant canopy, photosynthesis, shading methods, spectral quality, artificial light, LED, HID, interlighting, light absorption, temperature control, plant hormones, auxin, cytokinin, ethylene, Albany Technical College