Tweak, tweak, tweak, getting her set up for the switch. Double net this time. Going to oversaturate with red wavelengths for a week before we dial her in. I dropped her to 12 hours and upped the PPFD accordingly. Waiting game for now. Last grow I was not sure if it was me messing with darkness or if my overloading of sugar, possible it was too much nitrogen too, but I felt the flower was delayed quite a bit from what I was used to. Could not put my finger on it at first. "High concentrations of sugar can delay flowering by extending the late vegetative phase. This delays the activation of LFY expression, which controls floral transition. Sugar signals are involved in all key transitions of the plant life cycle. Sugar signaling interacts with hormone signaling pathways." "N is one of the most abundant nutrients required for plant growth and affects plant developmental regulation including flowering. The effects of N on the flowering regulation differ depending on the concentrations, as both a depletion and an excess of N cause a delay of flowering." Red light wavelengths interact with phytochromes to affect plant morphology, between 600–700 nanometers (nm) encouraging budding and flowering. Red light affects hormones like auxins, which control how plants stretch and develop flowers. Phytochromes also play a role in shade avoidance and sensing changes in the local light environment and time of year. The aim is to replicate nature, UVA peak + predominantly reds at sunrise UVB peaks at noon UVA peak + predominantly far-reds at sunset Also has a light coating of 850nm&940nm IR, 45% of the sunlight that reaches the surface of the earth is IR, Infrared (IR) light primarily provides heat to plants, which can be beneficial for growth within a certain range, but too much IR can cause stress, damage, and even kill plants due to excessive heat, disrupting their normal photosynthetic processes; while plants don't directly use IR for photosynthesis, it can influence aspects like flowering and leaf expansion when present in appropriate amounts. Particularly in the far-red wavelengths, can trigger the shade avoidance response, where plants sense a lack of direct light and accelerate stem growth to reach for better light conditions. This is especially useful in indoor environments where light conditions are carefully managed. Increasing this light can affect the growth speed of plants' stems. A short exposure to infrared increases the space between nodes. However too much infrared may actually damage plants. Because infrared is a kind of light that can emit a great deal of heat. While the spectral composition of sunlight at both sunrise and sunset is essentially the same, the key difference lies in the increased scattering of shorter wavelengths like blue and violet light during these times due to the longer path the sunlight takes through the atmosphere, resulting in a more pronounced red and orange color at the horizon, as these longer wavelengths are scattered less and reach our eyes more readily. A sunset generally has more far-red light than a sunrise because the sunlight travels through a longer path through the atmosphere at sunset, causing more blue light to scatter and leaving a greater proportion of red and far-red wavelengths visible to the eye. The Pr/Pfr ratio is the ratio of phytochrome Pr to phytochrome Pfr in a plant. The ratio changes throughout the day and night, and it affects how the plant grows and flowers. How the ratio changes? Daytime: Red light converts Pr to Pfr, so the ratio is low. Nighttime: Far-red light converts Pfr to Pr, so the ratio is high. Seasons: The ratio changes with the seasons because of the length of the days and the position of the sun. How does the ratio affect the plant? Photomorphogenesis: The ratio triggers photomorphogenesis, which is when a seed transforms into a sprout. Flowering: The ratio affects whether short-day or long-day plants flower. Growth: The ratio affects how much a plant grows. For example, a lower ratio of red to far-red light can improve a plant's growth under salinity conditions. How do plants sense the ratio? Plants use pigments to sense the ratio of red to far-red light. Using the phytochrome system to measure the ratio at dawn and dusk. The phytochrome system helps plants adjust their growth according to the seasons. Ratio. In controlled environment agriculture, customized light treatments using light-emitting diodes are crucial to improving crop yield and quality. Red (R; 600-700 nm) and blue light (B; 400-500 nm) are two major parts of photosynthetically active radiation (PAR), often preferred in crop production. Far-red radiation (FR; 700-800 nm), although not part of PAR, can also affect photosynthesis and can have profound effects on a range of morphological and physiological processes. However, interactions between different red and blue light ratios (R:B) and FR on promoting yield and nutritionally relevant compounds in crops remain unknown. Here, lettuce was grown at 200 µmol m-2 s-1 PAR under three different R:B ratios: R:B87.5:12.5 (12.5% blue), R:B75:25 (25% blue), and R:B60:40 (40% blue) without FR. Each treatment was also performed with supplementary FR (50 µmol m-2 s-1; R:B87.5:12.5+FR, R:B75:25+FR, and R:B60:40+FR). White light with and without FR (W and W+FR) were used as control treatments comprising of 72.5% red, 19% green, and 8.5% blue light. Decreasing the R:B ratio from R:B87.5:12.5 to R:B60:40, there was a decrease in fresh weight (20%) and carbohydrate concentration (48% reduction in both sugars and starch), whereas pigment concentrations (anthocyanins, chlorophyll, and carotenoids), phenolic compounds, and various minerals all increased. These results contrasted the effects of FR supplementation in the growth spectra; when supplementing FR to different R:B backgrounds, we found a significant increase in plant fresh weight, dry weight, total soluble sugars, and starch. Additionally, FR decreased concentrations of anthocyanins, phenolic compounds, and various minerals. Although blue light and FR effects appear to directly contrast, blue and FR light did not have interactive effects together when considering plant growth, morphology, and nutritional content. Therefore, the individual benefits of increased blue light fraction and supplementary FR radiation can be combined and used cooperatively to produce crops of desired quality: adding FR increases growth and carbohydrate concentration while increasing the blue fraction increases nutritional value. https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1383100/full Here are a few examples of good time lapse intervals based on the subject: Fast-moving clouds, traffic: 1-2 seconds Sunsets, sunrises, slower clouds: 2-5 seconds Moving shadows, sun across the sky (no clouds): 15-30 seconds Star trails: 30 seconds or longer Plant growth, construction projects: Minutes or longer intervals