Feedback letter on LED experiment.
The experiment with LEDs was conducted on “Meva” cucumbers according to the agreement No. 18-01 / 2017 between LLC “Agroculture Group” (Russia) and LLC “Inter-privat” (Ukraine) at the department 1.2 of a greenhouse facility of LLC “Agroculture Group” on an area of 465 m (control group plants area 15 705 m), with Elena Zaitseva as a foreman.
During the study, same nutrition and microclimate conditions were maintained for control and experiment groups, as well as general lighting. The results are shown in the attached table.
The experiment was held from March 6 to April 26, 2017 for 7 calendar weeks (from 10th to 16th). The goal of the experiment was to achieve an increase in the total of cucumbers cultivated in the area allocated for testing by 15% without reducing crop quality of the same hybrid.
In March (weeks 10-13), the controlled group plant running total yield was 13.9 kg / m2; plants cultivated with the use of LED coenosis-sensitive supplementary lighting had 14.3 kg / m2. Single plant from the control group was replaced due to its mechanical damage. No plants died-out in the experimental group. The quality of the fruits was the same for control and experimental groups and corresponded to the 1st grade. Average for March (control / experiment): number of fruits on the plant 16.5 / 15; average fruit weight (g) 191.75 / 189.25; Stem gain (cm) 39.25 / 42.25; number of leaves is 18.5 / 23.75; number of leaves per week gain 4.75 / 5.25; internode length between flowers (cm) 7.25 / 7.75; stem thickness above the top flowering axil (mm) 7.13 / 7.25; flower diameter (mm) 48,75 / 48. Thus, according to the March results, the difference in yield from between control group and the experiment group was less than 3%.
In the month of April (weeks 14-16), the controlled group plant running total yield was 24.2 kg / m2; plants cultivated with the use of supplementary LED lighting had 24.6 kg / m2. Quality of fruits both control and in the experimental groups was 1 class. No plants died-out. April average (control / experiment): number of fruits per plant 17/15; average fruit weight (g) 188/187; Stem gain (cm) 43.8 / 40; number of leaves 19.7 / 22; leaves per week gain 5 / 5,3; internode length between flowers (cm) 6,7 / 7, 5; stem thickness above the top flowering axil (mm) 6.8 / 7.0; flower diameter (mm) 46,0 / 51,3.
Thus, while preserving fruit quality, the difference in yields in favor of the experimental group compared to a control group turned out to be insignificant (did not exceed 2%). Such result may be due to the fact that the experiment was held in spring season when the natural illumination became sufficiently high, and supplementary lighting, including LED, did not play a significant role in the development of plants.
LLC “Agroculture Group” representant, responsible for the carrying of the experiment
M.V. Shishkin _______________ 26.04.2017.
Appendix. Experimental data comparative table.