Nut burn or heat stress?

Temp:
80-85F
Soil:
Soilessmix with slow releasing fert
Water:
Tap water with unknown PH " haven`t got any meter for a while "
My bulb distance from my plant is around 2-3inches away, using cfls

what seems to be the problem? it looks like Nut burn but at the same time it does looks like heat stress also... i`am confused

ryavila said:

Temp:
80-85F
Soil:
Soilessmix with slow releasing fert
Water:
Tap water with unknown PH " haven`t got any meter for a while "
My bulb distance from my plant is around 2-3inches away, using cfls

what seems to be the problem? it looks like Nut burn but at the same time it does looks like heat stress also... i`am confused

Click to expand...

Looks like an edge burn from the bulb to me, only need touch those CFL's for a second or so to cause that.

I would not expect to see nutrient 'burn' in a plant that age! When we talk about 'nute burn' what we are describing is a situation where an excess of nutrient in the soil is taken up by the roots and distributed through the veins in the leaf in an attempt to rid itself of the excess.......... kind of a dumping process! Often you will see small brown spots appear along the veins then a gradual build up along the leaf edges. Just one over strength feed can be enough to cause this to happen. It is very common.

Heat stress is different again, characterised by 'cupping' of the leaf edges upwards. Normally a result of high temps and dry conditions.

Hope this helps.

It IS NOT heat stress. It is the start of nute burn, please ignore the above post as it is mainly incorrect. Nute burn can start instantly in any age of growth. The brown spot scenario described above is interveinal necrosis usually caused by ph fluctuation.

Ohhh thanks, after that incident i placed some water bowl to my grow box hope that helps, and i mist them regularly.

@Woomeister so the only solution for now is flushing em?

but ofcourse with filtered water.

No, you need to change the growing medium, slow release fertilser mediums are awful for young seedlings/plants and are very hard to use in general. I would change to another medium asap. Just to put your mind at rest about heat stress- I personally start all my seedlings under a 250W Envirolight with reflector and keep it no more than 1inch away, to burn the leaves they have to be touching for a while, they do NOT burn instantly. When they do burn they look like a dead leaf, yellow and crispy. Flushing is pointless with slow release nutes.

I see.. thanks well i guess i have to change to medium then

Woomeister said:

It IS NOT heat stress. It is the start of nute burn, please ignore the above post as it is mainly incorrect. Nute burn can start instantly in any age of growth. The brown spot scenario described above is interveinal necrosis usually caused by ph fluctuation.

Click to expand...

My comments and observations are based upon many years of growing. I did NOT say it was 'heat stress' at all! I described heat stress, but what I said was it could be a burn from a raised leaf touching a CFL momentarily...... I have done that myself and could show you a pic of a leaf edge that looks just like that from a quick touch of a bulb!

Re nute burn, well I disagree with you on this too. Stable PH with sudden overfeed WILL manifest itself in those brown spots along the veins followed by that edge burning and the browning of the leaf. What you see is a kind of dumping effect as the plant attempts to rid itself of excess nutrient drawn up via the root system, where else is it to go? PLenty of plants grown with slow release nutes my friend, nothing wrong with them so long as you remember not to introduce additional nutrients for several weeks.

Most problems are caused not by PH fluctuation but by excessive feeding when they just dont need it.

My point was that one would not expect to see nute burn on a plant that size and age! Plain PH'd water is all she needs.

i tried flushing her today, hope this will help.