What is this hard black stuff? - Page 2 - Indoor Grows - Hydro - International Cannagraphic Magazine Forums

soil margin · 03-16-2018, 10:07 PM

Yeah agree with the stem rot diagnosis. Looks like the rockwool cube is staying wet so long that the stem can't dry out properly which can help lead to the rot. Can you maybe take a couple more pictures to give a better look?

The simple solution is typically to just lower watering frequency. Every third day instead of every other day, etc. If your room humidity is too high/air stagnant it will definitely make this even worse as the cube will stay moist for much longer after watering, meaning the stem is basically always wet.

samiam · 03-16-2018, 10:38 PM

The humidity is at 30% they will not make it 3 days without water.

Wendull C. · 03-16-2018, 11:19 PM

Pythium seems to be a generic term for bacterial infections like fusarium, damping off, and others. The remedies are all still the same.

Use google and search stem rot bacterial infections in marijuana. I got plenty of info on the first page.

Natural high · 03-17-2018, 12:10 AM

Definitely damping off or stem rot as Wendull C and others have said. It is not that common in an established plant and mostly effects seedlings. It can be caused by numerous different fungi but in this case it looks like botrytis or grey mould. Unless it can be stopped asap it will probably kill the plant via destruction of the vascular tissues.

03-16-2018, 10:07 PM	#11
soil margin Member Join Date: May 2011 Location: Sunshine and Lollipops Posts: 808	Yeah agree with the stem rot diagnosis. Looks like the rockwool cube is staying wet so long that the stem can't dry out properly which can help lead to the rot. Can you maybe take a couple more pictures to give a better look? The simple solution is typically to just lower watering frequency. Every third day instead of every other day, etc. If your room humidity is too high/air stagnant it will definitely make this even worse as the cube will stay moist for much longer after watering, meaning the stem is basically always wet.
	Quote

03-16-2018, 10:38 PM	#12
samiam Member Join Date: Jan 2017 Location: colorado Posts: 198	The humidity is at 30% they will not make it 3 days without water.
	Quote

03-16-2018, 11:19 PM	#13
Wendull C. Senior Member Join Date: Nov 2012 Location: Where the peaks meet the sky Posts: 1,370	Pythium seems to be a generic term for bacterial infections like fusarium, damping off, and others. The remedies are all still the same. Use google and search stem rot bacterial infections in marijuana. I got plenty of info on the first page.
	Quote

03-17-2018, 12:10 AM	#14
Natural high Member Join Date: Dec 2016 Posts: 524	Definitely damping off or stem rot as Wendull C and others have said. It is not that common in an established plant and mostly effects seedlings. It can be caused by numerous different fungi but in this case it looks like botrytis or grey mould. Unless it can be stopped asap it will probably kill the plant via destruction of the vascular tissues.
	Quote