Are gnats yellowing my leaves?

[Trespasser]

Hi,

I've got gnats. Lots and lots of gnats. My lower leaves are also yellowing and dieing, even the new growth!

Could the two be related?

I heard that watering with 1-part of 3% hydrogen peroxide mixed with 4-parts of water is the fix for gnats. Does that sound about right, or am I going to finish the plants off that way?

Tressie

[max11max]

Originally Posted by Trespasser

Hi,

I've got gnats. Lots and lots of gnats. My lower leaves are also yellowing and dieing, even the new growth!

Could the two be related?

I heard that watering with 1-part of 3% hydrogen peroxide mixed with 4-parts of water is the fix for gnats. Does that sound about right, or am I going to finish the plants off that way?

Tressie

Damage from the fungus gnat larvae feeding on the roots shows up in the leaves as overfertilization and nutrient deficiency symptoms: yellowing, browning, burning and curling leaves. Do you have this ?

If so then you need to hang them yellow fly traps and use Gnatrol or Mosquito Dunks for eradication.

Never seen h2o2 fix this problem, have you seen another post that suggests it works ??

[hindu420]

the hydrogen does work, but only on larve....the eggs in the soil r not affected and hatch l8r to cause more probs.

if uv a lg scale gnat problem then uv millions of larve in the soil, they eat mold fungus and root hairs...if the 1st to are not avalible they can desimate a grow....i.e. soiless and hydro.

if u us a small cab u can easily put a no pest strip in it to kill the adults, but this will still leave the larve which can be dealt w/in several ways, mosito dunks r easiest in hydro and soil. in hydro u can put in a nylon stocking and put in ur rez....w/soil/less u have to let the dunks sit for 24 hrs to activate, then water.....but as i said this just kills the larve not the eggs, and the BTi is only good for 48 hrs in soiless and soil, so u must repeat...u can also put perlite or sand on ur medium as a toppping to prevent the adults emerging from laying any more eggs. the perlite and sand make it where the gnat cant lay eggs because it is too sharp for thier egg laying parts to penatrate w/o damage. it cuts them up....i sugggest perlite as a topping because its so much lighter...

u must cover drain holes too in pots, because the gnats will simpley migrate to them and keep on keeping on laying eggs....i know of nothing that wiil kill the eggs them selves....they can survive floods, heat, and damage.....


well if u need more info just zap me....ill tag this thread.... if gnat get in ur clone room ur screwed,,,,imho...reasoning is they have nothing to eat nut the new roots, hence they die,,,


ok enouh 4now....l8r

[Trespasser]

Hi hindu420 & max11max,

Hmm, that accounts for the yellowing leaves then. Gnat larvae are eating my root hairs.

Oh, crap! Seems I have big problems. I don't know what gnatrol or mosquito dunks are. I can't even get a yellow fly control thingy as they've stopped selling them where I live. Looks like I'm screwed for this crop.

Okay, I'll try hydrogen peroxide a couple of times. Seems I don't have a lot to lose at this stage.

Argh! Why did I use Jiffy cubes? They were infested with gnat eggs, so I've been doomed right from the start. Never again.

Oh well, I'll just send what's left of this crop outside to mature and then start again inside with fresh everything.

Thanks for the invaluable advice guys.

Regards,
Tressie