Problems grow hemp seedlings using LED / Blue lite

Hello

We are test growing hemp seedlings in automated 40 foot container and using blue and red led. We are doing some work manipulating the spectrum and duration of light and are trying to learn if we are stressing the plants that might cause stunted growth or hermaphrodites.

We have found using 100% intensity red and 70% blue produces
stocky developed seedling. We are trying to get a little height so we were using more blue and less red but what really worked was alternating 3 hours red then 3 hours blue back and forth for 18 hours.

A grower I know mentioned using higher intensity blue relative to the red is that it can cause lower growth want to vegetate and the upper growth will want to flower. I have seen some mentioning of excessive blue light might be harmful during flowering but am curious if a seedling might be stressed enough to cause it to hermaphrodite when reaching flower stage.

We are also sexting the hemp, going 18-6 DLI for 18 days the switching to 12-12 DLI. We did have some male and female expression after 6 days in the 12-12. We have read the females would revert back to vegetative state after returning to 18-6 but again my farmer friend thinks I might be stunting the plants by changing DLI.

Am wondering is anybody has seen side effects of using blue lighting during seedling stage.

I mean hemp is cannabis.. and cannabis is hemp, the only difference is legal legislation discerning a difference based upon d9THC %. Prior till prohibition they were equals.

People grow cannabis, both flower and veg, under cheapo blurple lighting with success and blurples are garbage for flower as theyre like 70% blue light. So you shouldnt have problems with vegging under blue light. Thats vegetative growth's spectrum.

I veg under a Phlizon 3000w led, LED equivalent to 1000Watt HPS. It has 6 COB cree's plus has blue/red light boards. Veg mode, Blue light and white light switch to full spectrum LED for flower.

Lights light stats (idk if this helps)
3pcs 6000K COB
3pcs 3000K COB
110pcs 630-660nm
16pcs 470nm
12pcs Cool white 6500K
6pcs IR 740nm

Ive even germinated under blue light LED and flipped to full spec white light LED (Perfect Sun Goliath), two different lights, once seedlings broke soil.. because i had plants still running under the goliath. all success. Ive used germination specific lights (like a t5 led tube lights) for veg and Goliath for flower, all successes. Ive strictly vegged and flowered under the goliaths full spectrum white light as well with success.

Im actually about to germinate a decent bit of hemp seeds under my Phlizon 3000W for our licensed hemp grow after the 28th for a phenohunt. Just need to decide which cultivar to phenohunt for.

I believe you're talking about revegging ? Though im not sure why or what your question is. Cannabis can reveg but not all cultivars Express this trait. It takes a while, sometime a few months. Why reveg seedlings you just popped?

As far as i know, there are no side effects of blue light during veg as blue light drives vegetative growth. If youre having trouble germinating it might be your methods and order of operations and not the light. Could be light height is wrong, germination method is poor, overwatering seedlings, room isnt dialed in, low rH, poor pH, nutrient rich soil, etc. No clue if this helps.

My advice is to focus on growing the plant rather than playing with the lights. Environment is important but let's put it this way, is your cannabis at least as good as the best indoor product from twenty years ago? If the answer is no then focus on how to grow instead of thinking you are at the edge of some new thing.


Sexing the plants to find males and then going back to veg sounds reasonable to me. You can also take cuttings or send samples to a lab but changing the light schedule sounds like the easiest or most doable for someone on a budget in a short time. The argument would be whether a company can even help you sex the plants, it would have to be a lot more economy of scale stuff that does not benefit any home grower.


When companies advertise products specifically to commercial growers
it is advertising their attempt at eliminating the "middle man" or "competition" in this case home growers
it is effectively lobbying against home cultivation, to advertise products specifically for commercial grows

Ther are some studies done on using more blue lighting or other wavelengths in very early seedling stage and manipulation of the sexual expression..im not to sure how indepth these were done and if they were done in a controled environment and wether they could be replicated time an time again...but might be worth looking into

Thank you for your kind replies, Not sure if this forum is correct but we are business that developed a 40 foot container to grow seedlings or baby greens. The the internal environment and all internal movements is programmable and controlled by the system. We are growing cucumbers, tomato, and tobacco seedlings, and see hemp and cannabis as a good crop to grow. We are going to be testing growing stem propagation and eventually micro propagation with the aim of entering the legal cannabis market.

Not sure if this website is geared towards home growers or if there are commercial growers involved as well. Our aim is to produce a system to help farmers by growing hemp seedlings in spring and summer and baby greens in fall and winter economically and ecologically.

We are now testing different environmental parameters to see what works best to grow hemp, some recipes work better than others but we are very new to this and have a lot to learn. Some farmers have asked us try to sext the plants during seedling stage as it can be difficult after transplanting into a field during normal flowering.

JHelm said:

Thank you for your kind replies, Not sure if this forum is correct but we are business that developed a 40 foot container to grow seedlings or baby greens. The the internal environment and all internal movements is programmable and controlled by the system. We are growing cucumbers, tomato, and tobacco seedlings, and see hemp and cannabis as a good crop to grow. We are going to be testing growing stem propagation and eventually micro propagation with the aim of entering the legal cannabis market.

Not sure if this website is geared towards home growers or if there are commercial growers involved as well. Our aim is to produce a system to help farmers by growing hemp seedlings in spring and summer and baby greens in fall and winter economically and ecologically.

We are now testing different environmental parameters to see what works best to grow hemp, some recipes work better than others but we are very new to this and have a lot to learn. Some farmers have asked us try to sext the plants during seedling stage as it can be difficult after transplanting into a field during normal flowering.

Click to expand...

Therea home grow, medical growers, caregivers and commercial growers on here.

Why not veg, take cuts, keep originals as "moms" in veg and then veg the clones until theyre big enough and flip 12-12 lighting for sex. Then you know which gender the "moms" are and can allocate them to their prospective rooms (mom/dad) . This allows you to have the original plant to take cuts from with no genetic drift like a clone has. Not taking a cut of a cut of a cut. Also means you dont have to wait weeks for revegging.

Is this container like a greenhouse? Giant germination dome? Do you have pictures? Why so big? I understand its for commercial but it seems kinda odd, a 40 foot starter container, im interested and confused. I assume the benefit of it would be it has built in temperature control and rH control and is plug and play. Instead of dialing in a room with AC and humidifiers or dehumidifiers plus heaters and all that fun stuff.

Curious whats the benefits of your container versus using a heating mat/dome and starter tray in dialed in room for propagation/germination? My family is starting a small farm and market (organic CBD flower plus organic produce and bulk dry food) and i need staggered harvests for CBD hemp cultivars, variety of peppers, tomatoes, herbs, herbal tea garden, microgreens, leafy greens, beans, legumes and other odds and ends. Was planning weekly germinations for weekly harvests.. so something like this is kind of intriguing if its better than current systems.

The container is insulated 40 foot container, the system is programmable and automated to the point a grower would roll off 2 racks of product and roll in 2 racks of seeded trays. The system handles all interior movements and the environmental controls. The lights are are kept 3-5 inch from the leaf tips requiring less power and to maximize space potential inside the container.

We can grow between 40-60 lbs a day of baby greens depending on varietal. Seedlings we can produce 900 - 2500 a day depending on the amount of time it takes to grow. Hemp is working out to be about 18 days in the system so we get 1728 seedlings a day.

We just put in our first cuttings this weekend and are very excited, should see later this week if we get good rooting. We think it will work well as our biggest problem is getting the hemp seedlings to grow without getting root bound. Using 72 cell trays but may have to go to 50 cell trays. Once we get stem propagation dialed in we will try some micro propagation.

Trying not to cross a line with advertising on the site, so don't want to post link but if you would send me a message I would be happy to supply you with more specific information.

grown out arids\afterthought hemp. you need full spectrum, not just blue. did mine on 400w led 12/12 x 3.75 mos in 5 gallon. beautiful! ac/dc x abacus. mwah!