YOUNG PLANTS & LIGHTING Figure 1. Non-horticultural LED lamps installed in this greenhouse have filled up with water. Feit Eletirc A-19 GE ArizeTM Greenhouse Pro LED Plant Grow Light TotalGrow Pure their short life span and energy inefficiency. DE and NI lighting emitting 2 to 3 µmol∙m-2∙s-1 of red (R; 600700 nm) radiation is sufficient at inhibiting flowering of most SDPs and promoting flowering of some, but not all, LDPs. Therefore, both R and far-red (FR; 700-800 nm) radiation must be applied together to promote flowering in most LDPs. Previous MSU research has determined that off-the-shelf coolwhite and warm-white light-emitting diodes (LEDs) for home lighting applications can induce flowering of most, but not all LDPs (see https:// gpnmag.com/article/evaluatingdifferent-colors-leds-controlflowering for more information). A variety of low-intensity screw-in LEDs designed for commercial greenhouse or home gardening applications are currently on the market, each providing unique wavelengths (color, light quality or spectrum) of light. The potential exists for greenhouse growers to significantly reduce their energy costs with horticultural LED lamps tailored with specific spectra to hasten flowering of LDPs and potentially reduce stem elongation compared to INC lamps. Given the numerous options, which lamps should growers select Photoperiodic LED Lamp Philips GreenPower LED Flowering 200 Lamp flowering lamp DR/W/FR 2.0 Figure 2. Low-intensity LED lamps used in the study. given that the cost of each LED lamp can vary from $10 to over $45 each? Why not just use an inexpensive white LED screw-in lamp if they will induce most LDPs into flower? GREENHOUSE PRODUCT NEWS 29http://www.gpnmag.com/article/evaluating