My video number 35 dealt with the harvesting and storage of onions. In the process of harvesting, I noticed that some onions showed signs of onion white rot.
This can be very problematic as it attacks onions, garlic and other alliums, and there is no recommended commercial treatment currently available for gardeners.
It causes a white fluffy fungus to appear on the onions, which kills the roots and can go on to destroy the whole onion. It is also said that it can remain in the soil for between eight and twenty years, and so is hard to eradicate.
However, there is a scientific paper on the Internet which describe research into treating infected soil with onion powder, garlic powder, onion oil, garlic oil and allium wastes.
That paper can be read at: www.sciencedir....
The rationale behind that approach follows from the idea that latent fungus in the soil is activated by sensing a chemical called allicin, which is released by maturing alliums and contributes to their characteristic smell.
It is postulated that if that chemical can be introduced to the soil it will trick the fungus into activating and, finding no host plant to infect, will die.
The above paper indicates that this seems to have some effect.
This video describes the beginning of my attempt to try this. I explain the process I have decided to use in the video.
The calculations that led me to use 0.5kg of garlic powder on the bed are as follows:
The experiments described in the above paper used a dosage rate of 0.1%. It is also said that the fungus remains in the upper part of the soil - which makes sense because that’s where the onions are! I have assumed that depth to be 0.1m.
The total volume of soil to be treated, therefore is the length of the bed X the width of the bed X a depth of 0.1m.
For my bed, that is: 2.75m X 1.1m X 0.1 m = 0.303 cubic metres.
The standard density of topsoil is 1,600kgs per cubic metre.
The weight of the soil to be treated is therefore: 1,600 X 0.303 = 484.8kgs
0.1% (one thousandth) of that weight is around 0.5kg.
If you have tried this, or similar, or want to contact me about it, please email me at gardening@huggett.info.
27 июл 2021
