Seedling health

[tipz]

Ok, wondering if someone could reassure me with what looks like a potential problem with my seedlings ?

I recieved a few different varieties of cacti seed from sab a few weeks ago. I obtained some coarse sharp sand, and filtered it to the desired particle size. This sand was fully pastuerised and put into a small heated propagation box brought from bunnings ( fully sterilised with boiling water also )

The seed box was placed in a small grow tent under 18 hours of light ( hps 400 ), with the propagation box being a metre from the lamp.

Temps during "day" are no higher than 30c and drop to 16c at night. Unfortunately i had a zero% success rate.

Just last week some more seed i ordered arrived from a different source. As the propagation chamber still seemed to be sterile i simply sprinkled this seed onto the pre-pepared sand. It is now four days and some very healthy little seedlings are starting to emerge. My problem is that the surface of the sand mix is starting to turn green with what looks like algae ??? I grabbed some fongarid ( a systemic fungacide ) and sprayed the surface and the seedlings with this solution. Is there anything else i can do, or do i not need to even worry ?

Also i have neverending problems with spidermite in my room, and am wondering if it is ok to spray with mite-rid when the little suckers inevitably show up ?

Any help would be much appreciated !

cheers guys

[gogogadget]

are you sure it's spidermite and not fungus gnats?, also i wouldn't use fongarid on plants intended for consumption think pup trading...but DE earth is a good alternative and or good nematodes, but i wouldn't worry about the green algy unless it becomes a problem but eco rose from bunnings is organic and kills this i have used it with great results.

[tipz]

Most definately spidermites, millions of the little bastards ! i have had gnats but they are not a recurring problem. If i dont stay on top of the mites, i end up with webbing all over my broccoli. Mit-rid is certified on use for organic applications so that should be ok.

The main concern was the surface algae... so its reassuring to hear it should be fine. I suppose algae is not a fungus is it so the systemic fungacide was probably unnecessary.

Well fingers crossed ! If unsuccessfull i think i may invest in a number of pre-established specimens.

Many thanks gogo.. i can now sleep well tonight.

[gogogadget]

the fungi will come naturally as the chlorine evaps from the water, and is just the stuff you see in aquariums on the side, i see it mainly on perlite but try to let at least the top 1st 1-2mm dry before re-applying i assume this would help slow down growth as it can become abundant but it wont harm your seedlings also with spidermite, i wouldn't try it myself but oxyplus for hydro applications will kill anything in the soil level just a weak solution for seedlings, and i've used bounce back with good results also even though it says nothing on the bottle about killing them it does work.

ps, watering with rainwater and bottled water is a plus as chlorinated water kills microbes

Edited June 14, 2011 by gogogadget

[Gunter]

good luck, this type of thing tends to happen with the sterile media

next time try a living soil media without sterilizing things, this prevents the algae bloom and cacti do just as well if not better than they do with axenic medias.

why fight nature when you can work with it? Not all fungi are bad for cactus seedlings, many are very good. The same can be said for bacteria. Using coarse sharp sand as a media might also invite problems, cacti do not ordinarily grow in such a media in nature.

Growing cactus seedlings is very easy without sterilizing things or using any insecticide, fungicide etc. Those things tend to create imbalances that you will have to endlessly compensate for.