VERTICAL FARMING (VF) IS A FORM OF COMPLETELY INDOOR CONTROLLED-ENVIRONMENT AGRICULTURE IN WHICH SUNLIGHT IS NOT USED TO GROW CROPS, SO SOLE-SOURCE ELECTRICAL LIGHTING IS A MAJOR ENVIRONEMNTALINPUT COST, AND ENERGY SAVINGS IS A MAJOR ISSUE FOR COMMERCIAL GROWERS. AS A RESULT, MOST VF GROWERS EMPHASIZE QUICK-TURNING LEAFY GREENS AND CULINARY HERBS WITH GOOD MARKET RETURNS. NEVERTHELESS, VF IS A YOUNG GROWTH INDUSTRY FOR WHICH PROFITABILITY IS FRAGILE, AND SOMETIMES ELUSIVE, SO GROWERS LOOK FOR WAYS TO TRIM ENERGY COSTS FOR LIGHTING THEIR INDOOR CROPS, ONE OF THEIR BIGGEST PRODUCTION EXPENSES! THIS RESEARCH PROJECT OFFERS THREE APPROACHES TO SIGNIFICANTLY REDUCE ENERGY INPUTS FOR INDOOR CROP LIGHTING, EACHOF WHICH DEPENDS ON A DIFFERENT UNIQUE PROPERTY OF LIGHT-EMITTING DIODES (LEDS), THE CONSENSUS CHOICE OF LIGHT SOURCE FOR INDOOR FARMING. THE FIRST APPROACH DEPENDS ON THE PROPERTY OF LEDS TO BE RELATIVELY COOL AT THEIR LIGHT-EMITTING SURFACES, WHICH ALLOWS CLOSE SPACING BETWEEN LIGHTSAND PLANTS WITHOUT OVERHEATING OR SCORCHING THE PLANTS. THIS COOLNESS FACTOR,THEN,ALLOWS THE ELECTRICAL POWER NEEDED TO DELIVER A GIVEN LIGHT INTENSITYTO BE TUNED WAY DOWN COMPARED TO WHAT WOULD BE REQUIRED FOR A HOT LIGHT SOURCE TO ACHIEVE TH SAME LIGHT INTENSITY AT A CONSIDERABLYLARGER SEPARATION DISTANCE. THUS, ONE PHASE OF THE PROJECT WILL INVOLVE CHARACTERIZING AND OPTIMIZING CLOSE-CANOPY LED LIGHTING, MEASURING CROP YIELD WITH ENERGY SAVINGS AT THE SAME TIME. ANOTHER APPROACH WILL BE TO CAPITALIZE ON THE UNIQUE PROPERTIY OF LEDS TO BE SELECTIVELY SWITCHABLE AND DIMMABLE, BY COLOR, OR INDIVIDUALLY BY POSITION. WHEN COUPLED WITH AN EFFECTIVE SYSTEM TO DETECT THE SIZE AND POSITION OF PLANTS LOCATED WITHIN A CROP STAND BELOW THE LED ARRAY, AND THE PROCESS AUTOMATED, A TARGETED LIGHTING SYSTEM WILL RESULT WITH POTENTIAL TO SAVE CONSIDERBLE ELECTRICAL ENERGY OVER THECOURSE OF A CROPPING CYCLE BY NOT ALLOWING PHOTONS OF LIGHT TO FALL ON GROWTH SURFACES BETWEEN PLANTS THAT ARE NOTPOPULATED BY PHOTOSYNTHESIZING PLANT TISSUES. BECAUSE PLANTS GO THROUGH DISTINCT GROWTH PHASES DURING A CROP-PRODUCTION CYCLE WHEN THEY HAVE DIFFERENT SENSITIVITIESTO ENVIRONMENTAL FACTORS LIKE LIGHT, CARBON DIOXIDE, AND TEMPERATURE, A NOVEL TOOL HAS BEEN DEVELOPED THAT CAN CONTINUOUSLY MONITOR PLANT RESPONSIVENESS TO FACTORS SUCH AS LIGHT ITENSITY, LIGHT COLOR, AND/OR CARBON DIOXIDE CONCENTRATION. IN THIS APPROACH, THE NOVELPROPERTY OF SELECTIVELY DIMMING OR BRIGHTENING LEDS WILL BE LEVERAGED TO CREATE RATIOS OF SPECIFIC COLORS OF LIGHT THAT WILL MAINTAIN PLANTS IN A DESIRED DEVELOPMENTAL STATE, OR THAT CAN PROMOTE LEAF EXPANSION WHEN IT IS DESIRED, WILL BE COMBINED WITH MONITORING THE PHYSIOLOGICAL STATE OF PLANTS TO PROMOTE GROWTH WHILE SAVING ENERGY. JUST IN CASE THE WHOLE IS GREATER THAN THE SUM OF ITS PARTS, ALL THREE APROACHES TO POTENTIAL ENERGY SAVINGS WILL BE INTEGRATED TOGETHER FOR MAXIMUM ENERGY SAVINGS DURING SOLE-SOURCE LIGHTING OF LEAFY GREENS OVER THE COURSE OF ENTIRE CROP-PRODUCTION CYCLES. IT IS CONSERVATIVELY ESTIMATED THAT COMBINED ENERGY SAVINGS FOR THE THREE APPROACHES TO BE TESTED IN THIS RESEARCH PROJECT WILL RESULT IN AT LEAST AN ORDER OF MAGNITUDE ENERGY SAVINGS COMPARED TO TRADITIONAL OVERHEAD LED LIGHTING AS CURRENTLY PRACTICED IN VERTICAL FARMING. THIS COULD BE A GAME CHANGER IN TERMS OF PROFITABILITY, PRODUCTIVITY, AND SUSTAINABILITY FOR INDOOR VERTICAL FARMING!