I have a little something to share with you guys, that I actually learned in college *cheers*!
I graduated with degrees in biology and biochemistry. For my biochem senior thesis, I collected, extracted, purified, tested, and isolated anti-fungal compounds from mosses and lichens that I purchased or collected. A ton of work, unfortunately, with little usable result.
Anyway, my research adviser had come across some papers which talked about the wonderful anti-fungal properties of Lemon Grass. We purchased some extract off the internet and went directly to our bio-assay to test activity.
We plated three types of fungus. Saccharomyces cerevisiae, Candida albicans, and Aspergillus niger. We soaked some sterile paper discs in different dilutions of the essential oil extract, placed them in triplicate on the agar plates, and waited for the results.
Three days later we couldn't believe our eyes. Even the most diluted of samples had inhibited growth to an extent that we had never witnessed, even when using the control anti-fungals.
I suspect this \"natural\" anti-fungal could be used on plants with great effect, if other options are unavailable or have not produced results.
Since this is an essential oil, it must be made into an emulsion or put into a solution that it is miscible in before it is sprayed on plants.
Mixing it with some soapy water and shaking it up a lot would probably work to create a diluted foliar spray.
Also, I have never actually sprayed a plant with lemongrass extract so you would definitely want to test if the extract is poison to the plant before spraying your whole crop (it is very unlikely that this is toxic to plants, but please make sure before use).
Thanks for your time and good luck keeping that mold away!
P.S: error: we did consider that the company which produced our extract may have been cleaning equipment with an anti-fungal that contaminated the oil, producing our wonderful results.. to measure reproducibility, we purchased a different extract and found that the results were nearly identical. we did not perform any of the extracts ourselves.
That is interesting.
I have often thought about using these types of natural anti-fungal oils for my ginseng as a preventative type thing. Are you familiar with other oils as well? One we use often is \"Melaleuca\" or Tea Tree Oil. This is just one of many links referencing it and at the bottom it references controlling some of the same types of fungus as your Lemon Grass does.
My wife has so many natural oil extracts that I can't keep track of all of them. All of these essential oils can be used to treat various aliments or illnesses etc. Many of them are anti-fungal etc.
I have read a lot of research on the antimicrobial effects of tea tree oil, especially its anti fungal properties. It was actually one of the controls I used in my study.
It did indeed inhibit the yeast and the black mold. One thing is for sure though, the minimum inhibitory concentration for Lemon Grass extract was much lower in comparison to the tea tree oil. We needed a 50% solution of the Tea Tree oil to mimic inhibition caused by a 20% Lemon Grass solution.
I think that the essential oil method of controlling mold is very practical. It may even be a great idea to put down a spray or two before you cover any seed with leaf litter. These oily extracts are usually \"terpenoid\" anti fungals, which are relatively broad spectrum in action (targets the fungal cell wall), and have also been shown to interfere with spore production. That's good news for the gardener.
Does anyone soak their ginseng seeds in a 1/10 concentration bleach to kill any foreign diseases before planting? I have heard of people doing this with other types of seed or rootstock in order to prevent the movement/spread of any plant pathogen. For example, some Iris enthusiasts soak their rhizomes to prevent rot.