Strange Yellow Blotches

[OldManRiver]

I am getting some strange blotching on several of my plants. These are seedlings, about a month old, which have been outside in partial light for about 10 days, moved to full light two days ago. Four of six plants are affected, two each of two different strains. One strain is unaffected. They are in Happy Frog soil, no additives, and have received two feedings of Botanicare Pro veg, mixed at less than half strength. They have been in these big pots since they were put outdoors. Nighttime temps are still a bit low, low to mid 40's. The plants have been growing vigorously, and still seem healthy. Water is about 7.0 pH. I am not a beginner, am being careful to not overwater, but they were moist from rain for about three days.

Thoughts? Light burn?

 

[Homesteader]

UV burn I think. I assume they will acclimate but you may want to shade it a few more hours during peak.

 

[OldManRiver]

UV burn I think. I assume it will acclimate.

I can live with that. They should be about hardened by now. Thanks.

 

[GT21]

I bet it goes away when it warms up

 

[OldManRiver]

I bet it goes away when it warms up

We'll find out, it's supposed to be high 70's for the coming week. I'm not too worried, the plants are generally vigorous.

 

[stonestacker]

More food.

 

[OldManRiver]

More food.

Well, these types of blotches don't show on any of the deficiencies charts, and the plants are otherwise pretty healthy. Plus they'd been fed twice, with a known good ferilizer. I doubt its a macro shortage.

 

[DGP]

Happy Frog comes out of the bag a little hot. I have always seen a little burn from it on my seedlings. So, I kinda doubt they are hungry yet but I have had to add calmag sometimes. Also, HF is awfully heavy, did you augment with perlite or anything? I add a lot of perlite to lighten it up.

 

[oldskol4evr]

even 70 outside on a beautiful day your girls can sunburn,the leaves will fall off and keep trucking,no problem,i know this cause my dumb ass always does it,hahah,i try like hell to stager the times hardening them off and cant depend on me hahah,i got some bell peppers i just hardened off,temp was 80 and i set them outside all day wind was about 15 mph,they loved it,next morning still pretty,got to 83 that day with no wind,after 6 hrs out,they started to stress,so i shaded them,next day sun burn leaves,so next day got to 87 no wind,around noon i went out and pointed a small fan at them on the back deck and they been rocking since,the burnt leaves fell off and been transplanted ,loving the sun wind or not now

 

[OldManRiver]

Happy Frog comes out of the bag a little hot. I have always seen a little burn from it on my seedlings. So, I kinda doubt they are hungry yet but I have had to add calmag sometimes. Also, HF is awfully heavy, did you augment with perlite or anything? I add a lot of perlite to lighten it up.

They aren't looking nute burned. Tips are fine, no edge burning, leaves have good rigor. The nute mix I gave them was pretty soft, and contains cal-mag. I'm thinking the guy above is right, I sunburned them a bit.

 

[OldManRiver]

even 70 outside on a beautiful day your girls can sunburn,the leaves will fall off and keep trucking,no problem,i know this cause my dumb ass always does it,hahah,i try like hell to stager the times hardening them off and cant depend on me hahah,i got some bell peppers i just hardened off,temp was 80 and i set them outside all day wind was about 15 mph,they loved it,next morning still pretty,got to 83 that day with no wind,after 6 hrs out,they started to stress,so i shaded them,next day sun burn leaves,so next day got to 87 no wind,around noon i went out and pointed a small fan at them on the back deck and they been rocking since,the burnt leaves fell off and been transplanted ,loving the sun wind or not now

Yeah, I thought I had hardened them sufficiently, 10 days in partial sun, but perhaps not. Sunburn I can live with, they will grow out of it. The weather here is supposed to be partly cloudly for the next few days, hopefully they will perk up.

 

[oldskol4evr]

Yeah, I thought I had hardened them sufficiently, 10 days in partial sun, but perhaps not. Sunburn I can live with, they will grow out of it. The weather here is supposed to be partly cloudly for the next few days, hopefully they will perk up.

i sit mine out 2 hrs first day and move in shade,next day i shoot for 4 hrs,if no stress cause the plant will scream at you if so,3rd day i try go whole hog,i watch and see when the leaves try to lay a bit and check time to see what they can take,next day after the time i calculated,i leave um a hour short when that went down dig,leave them out 2 days same time,all good throw there ass to the sun,the sunburn leaves will die back and nothing but new growth from there,hope that helps

 

[OldManRiver]

i sit mine out 2 hrs first day and move in shade,next day i shoot for 4 hrs,if no stress cause the plant will scream at you if so,3rd day i try go whole hog,i watch and see when the leaves try to lay a bit and check time to see what they can take,next day after the time i calculated,i leave um a hour short when that went down dig,leave them out 2 days same time,all good throw there ass to the sun,the sunburn leaves will die back and nothing but new growth from there,hope that helps

Yeah, I gave them 10 days in partial sun. Really surprised.

 

[Ignignokt]

Yeah, I gave them 10 days in partial sun. Really surprised.

This is the point of having some decent UV exposure early in veg. Makes the plant remarkably hardier and resistant to things that weaken, stunt or kill plants that have not been exposed. One thing to watch for are natural lenses, water drops that persist long enough to focus sunlight. I think perhaps that is what @GT21 is getting about warmer temps. When cannabis gets rocking with veg, it isn't unusual to see the water vapor discharged as part of photosynthesis begin collect just about there in the leaves condensing into liquid state, forming droplets. This can be way more noticeable indoors with very strong light where there is much less ventilation. You get very similar leaf blotches. Less light (shade) and you don't see the problem.

 

[OldManRiver]

Plants have been in full sun since, are recovering nicely with no treatment other than normal watering. I had given them a weak fertilizing when I noticed it, no food since. I think they are out of the woods. Note the new top growth color.