Is it ok to use general vegetarian agar as a sowing medium?

[kiwiorchids]

I am just curious, is it ok to use standard agar (the one used for consumption as a geletine sub) as long as i add the nutrients (by use of banana skin etc) for seed propagation?

THANKS IN ADVANCE

[Halloamey]

Yes Jordan it is perfectly fine to use it, I have used it on several instances. Just make sure it is plain agar with no flavoring agents and sugar already added. You should make the liquid medium by boiling it etc. then fill it in the bottles and then add the agar powder to it and then autoclave it. Never cook your agar on a direct stove with your media. Make the media separately and then add the agar later. This is our standard practice in the lab also. After adding the agar, you do not even need to shake it, during autoclaving it will melt and become homogenous with the medium. If you shake it it will stick to the sides of the bottle and and get stuck to it after autoclaving. 2 to 3 g per 100 ml should do the trick.

[kiwiorchids]

ok thanks, so in simple terms? sorry amey, im not up to scratch yet on the scientific stuff. So the media will be the nutrient ie boiled banana skin and other nutrients? and autoclave is when it is done in the pressure cooker?

[Halloamey]

Yes you first make the media by boiling the potatoes/ banana mash with the water strain the mixture add the fertilizer and sugar, fill it in the bottles, add the agar and then pressure cook it. The boiling of the banana and potatoes is for the extraction of nutrients from it as you take only the broth. Whereas the pressure cooking is for sterilizing the media to get rid of all bacteria and fungal spores that survive normal boiling temperature.

ok thanks, so in simple terms? sorry amey, im not up to scratch yet on the scientific stuff. So the media will be the nutrient ie boiled banana skin and other nutrients? and autoclave is when it is done in the pressure cooker?

[kiwiorchids]

ok. So i can use a banana/potato mash, then i strain that, add some sugar and some fertilizer. What would you recommend?

Then after that, i add how much to the jars? and then 2-3gm of agar powder to the broth?

I am using either 250ml or 500ml brand new chemical storage bottles. They wont have been used

[Halloamey]

The media I would recommend is a home made version of Knudson C medium. For 1 litre of this medium you will need; 100 gm Banana pulp, 50 ml Potato infusion, 100 ml coconut water (can be skipped with pure water), 1 g 20:10:20 NPK foliar fertilizer for orchids with 5% Calcium and 2% Magnesium (make sure the nitrogen is all nitrate and amonium nitrogen, no or very less urea nitrogen) Use a fertilizer that comes with chelated microelements like Fe, Cu, Zn, Mo etc. (I will PM you the fertilizer company and the technical analysis of the fertilizer I recommend but you could use any fertilizer which is similar in composition.) 20 g table sugar and 15 g agar, citric acid to adjust pH and distilled water.
Grate a small 50 to 100 g potato skin and all and add 200 ml of water to it. Then microwave on medium (400 to 600 w) for 10-15 minutes. Stirring occasionally and adding a little water at a time, so it doesn't dry and thicken. Then strain the resulting broth add the banana and process into a puree. Set aside to cool. Now take the coconut water add the sugar and let it dissolve, add the banana potato puree, mix thoroughly and then add 400 ml distilled water. To this add the fertilizer and mix thoroughly. You will now have about 700 ml of the broth. Now adjust the pH of the solution using citric acid solution (10 g acid in 100 ml water) which you can easily find at the grocery store or using lemon juice to get a pH of 5.5. (add only small quantities of the juice, if you add too much the pH will become too acidic, start with a teaspoon and add little till you get down to the right pH). After you have adjusted the pH adjust the volume to 1 litre using about 300 ml of distilled water. Now add about 50 ml to each of your bottles without coating the sides of the bottles and the mouth. (this prevents contamination) add 0.75 g agar to each bottle and then autoclave it. If you do not have a balance that weigh 0.75 g I would suggest heat a double pot water bath like you use to melt chocolate, add the 15 g agar to the litre of the broth you prepared DO NOT MIX or the powder will stick everywhere to the sides and form small granules. Now let it sit over the water bath for 20 to 30 minutes, now the agar should be melted, now you can mix the broth and then getly pour the mixture into the bottles, screw on the caps NOT tightly and then autoclave in the pressure cooker for 15 to 20 minutes. Let the media and the bottles cool down inside the pressure cooker. And you are ready !!

[nermal]

I've just got a question regarding your recipe:

Grate a small 50 to 100 g potato skin and all and add 200 ml of water to it. Then microwave on medium (400 to 600 w) for 10-15 minutes. Stirring occasionally and adding a little water at a time, so it doesn't dry and thicken. Then strain the resulting broth add the banana and process into a puree.

This might sound like a bit of a dumb question...but do you keep the liquid or the solid. I ask because the solid would have more starch...am I just overthinking something simple?

[Halloamey]

Hi Nermal, you have to take the liquid, as it contains all the water soluble starch and micronutrients like amino acids, vitamins etc. The solids will have a lot of starch, true, but it will complex and difficult for the plants to absorb and use. So you want only the simple sugars and nutrients that are easily water soluble and absorbed.

I've just got a question regarding your recipe:

This might sound like a bit of a dumb question...but do you keep the liquid or the solid. I ask because the solid would have more starch...am I just overthinking something simple?

[Ted Davis]

Amey...Excelent post...Question; Have you or anyone had any success using beef gelatin instead of agar as a growing substance...? Not new to the process, but wondering if I would be waisting my time and seed pods...Thanks a bunch and greetings from Chiang Rai.

[kiwiorchids]

ok thanks Amey, alot to digest, but its printed and on the wall infront of my desk...let the memorising begin!