We have a report of someone using cold fermented equisetum on the soil before planting potatoes: total success on 3 successive years in a field that always had blight. I know that Hugh Courtenay was a huge fan of this fermented 508, an idea he got from Lili Kolisko I believe.
At the same meeting another person used boiled up equisetum with success.
Another used an alcoholic extract of equisetum against Ash Die Back and all seems good so far.
There's Enzo's 508/equisetum whose story you read by clicking on the logo in the top left of your screen and then the circled I in the lower right of the next screen.
Glen wrote about equisetum and the circumstances in which he found success.
You can read what people have found about 508/ equisetum here and about the sporangia version here.
And there's many instances of little to no success.
Blight and equisetum
Re: Blight and equisetum
Manfred Klett Foundations and Principles of the Biodynamic Preparations
"Walter Stappung has documented the many different ways in which equisetum tea is prepared across the world, the length of time it is boiled and the subsequent fermentation to a liquid manure, as well as the cold fermentation of the fresh plant material, application times, quantity and frequency and whether the preparation only works preventatively or can treat an acute fungal attack.4 Out of the accumulated experiences of making the tea the following recipe can be given: 200–300 grams (7–10 oz) of dried herb is gently boiled in 10–20 litres (2½–5 gal) of water for one hour. With fresh plant material, 1½ kilograms (3 lb) is added to the same amount of water.5 A long period of simmering is recommended in order to break open the silica-coated peripheral cell tissues and keep this process in the universal and primal element of warmth. With regard to application Rudolf Steiner uses the concept ‘liquid manure’. This indicates that after it has been made, the horsetail tea should be fermented so that the heavier organic substances that are harder to break down can be extracted. With the formation of acids the tea becomes a liquid manure and, as a result, can be kept and used over a longer period. Only when it begins to putrefy and starts to stink of hydrogen sulphide (H2S), should it no longer be used. The frequently practised cold fermentation should also be avoided. With longer periods of fermentation, premature rotting and an insufficient opening up of the amorphous silicic acid can occur. The effect of warmth in the boiling process seems to be of key significance in making the silicic acid effective."
"A lot of experiments have been made, primarily in horticulture, that focus on reducing acute cases and other fungal disasters with the horsetail preparation.9 However, there are no long-term experimental trials regarding the prophylactic effect of the horsetail preparation. Trials of an exact nature exceed what is possible."
"Walter Stappung has documented the many different ways in which equisetum tea is prepared across the world, the length of time it is boiled and the subsequent fermentation to a liquid manure, as well as the cold fermentation of the fresh plant material, application times, quantity and frequency and whether the preparation only works preventatively or can treat an acute fungal attack.4 Out of the accumulated experiences of making the tea the following recipe can be given: 200–300 grams (7–10 oz) of dried herb is gently boiled in 10–20 litres (2½–5 gal) of water for one hour. With fresh plant material, 1½ kilograms (3 lb) is added to the same amount of water.5 A long period of simmering is recommended in order to break open the silica-coated peripheral cell tissues and keep this process in the universal and primal element of warmth. With regard to application Rudolf Steiner uses the concept ‘liquid manure’. This indicates that after it has been made, the horsetail tea should be fermented so that the heavier organic substances that are harder to break down can be extracted. With the formation of acids the tea becomes a liquid manure and, as a result, can be kept and used over a longer period. Only when it begins to putrefy and starts to stink of hydrogen sulphide (H2S), should it no longer be used. The frequently practised cold fermentation should also be avoided. With longer periods of fermentation, premature rotting and an insufficient opening up of the amorphous silicic acid can occur. The effect of warmth in the boiling process seems to be of key significance in making the silicic acid effective."
"A lot of experiments have been made, primarily in horticulture, that focus on reducing acute cases and other fungal disasters with the horsetail preparation.9 However, there are no long-term experimental trials regarding the prophylactic effect of the horsetail preparation. Trials of an exact nature exceed what is possible."