Editor’s note: We at Illinois News Joint believe combining academia and cannabis is one of the best ways to normalize cannabis and its community. As such, Illinois News Joint has been partnering with colleges and universities to incorporating an educational Scientific Grow Journal series that showcases scientific studies pertaining to the practices of growing better cannabis. This is the second entry in this series.
Dr. Dokyoung (D.K.) Lee, who is the crop sciences professor and director of online masters programs at the University of Illinois Urbana-Champaign, created this inaugural Scientific Grow Journal as part of his academic studies comparing two different light duration settings.
The purpose of this experiment is to better understand if turning off light for a certain period during the afternoon, when energy cost and chances of power outages are greater, would affect the yield of the cannabis plants. The experiment setup included two Lighthouse 2.0 4’x4’ tents installed with NextLight 420h LED Grow Light (sponsored by GroUp Gardening). The conditions for each grow tent were same, expect in one tent the light was turned on for 18 hours continuously (6-12 a.m.) and the other tent the light was turned off two hours from 2-4 p.m.
Lee left off the last journal entry by measuring the lighting distribution, distance, and spectrum in the tents. Lee is growing strains from his F-Line, G-Line, and S-Line that he propagated at the University of Illinois.
Other setups included 9 plants per tent and 3 plants per the 3 genotypes with a targeted temperature of 75-80F and targeted light intensity at 600 umol per square meter per second. The grow medium included Berger BM7 soil / Classic 600 (2-gallon) pot.
The plants were placed into the ten February 15 and harvested April 26. The heights of each plant were recorded three times per week. Other noticeable observations were also recorded.
The following light duration differences are listed in the graphic below. On March 10, all lights were switched to 12 hours on. However, one light was shut off for a two-hour dark period from 2-4 p.m. Check back soon for the next Scientific Grow Journal entry.
The plants were harvested April 29 and weighed. Check back soon for the next Scientific Grow Journal entry to find out the final results.
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