Preventing the spread of disease

[jdfnnl]

This year I have high hopes in a nice size crop of fava beans started in a new gardening location. At the same time I seeded some flats of leafy greens to transplant in a neighboring bed. Only thing is the seeding mix that I had made made from a previous garden had always imparted fava beans with a serious spat of fava bean rust (Uromyces viciae-fabae) later in the season. I am not sure how this fungus exists and spreads, if the spores can lie dormant in soil or if they are present only on fava plant matter. Given I would like to do everything possible to prevent this fungus from becoming established, it occurred to me I may have to sacrifice these the starts I intended to transplant. Am I being paranoid by my ignorance about this blight, or would I be better taking all the precautions? I am not sure how much this seeding mix was mingling with a prior fava bean crop, but do believe some of the soil is present in the mix. These sprouts are ready for new beds like tomorrow, so if anyone could steer me in the right direction ..

 

[headfullofbees]

I would try spraying with aspirin solution at 325mg per gallon (at that level it doesn't matter UK or US gal). Spray as a drench every fortnight.
Salicylic Acid acts like natural hormones in some plants to alert their defences. This is called Systemic Acquired Resistance, & is especially useful for toms & potatoes, but works on a number of other plants, so may work for fava.
Worth a try if you've exhausted other routes.

 

[DirtMechanic]

I found this in a white paper examining 11 fungicides used to control your rust in Spain:

"only treatments with triazoles and benzimidazole-triazole mixtures provided significant yield increases (22.7–15.6%) when applied twice."

Not sure which products are sold near you but the names may help with further reading and study.

 

[Meadowlark]

Well, I'd probably take a different approach than most...but I strongly believe in prevention rather than intervention. As such, I would make certain that no contaminated soil, none from your previous garden is allowed in the new space. If that means starting over, then so be it.

Make sure you carefully and systematically remove/burn any/all stubble that shows rust each year and ALWAYS practice rotation and soil replenishment. Prevention works for me.

 

[headfullofbees]

Well, I'd probably take a different approach than most...but I strongly believe in prevention rather than intervention. As such, I would make certain that no contaminated soil, none from your previous garden is allowed in the new space. If that means starting over, then so be it.

Make sure you carefully and systematically remove/burn any/all stubble that shows rust each year and ALWAYS practice rotation and soil replenishment. Prevention works for me.

Do you think heat sterilisation of the soil would work?

 

[Meadowlark]

Yes and no. I'm not a fan of sterilization of garden soil...because it kills everything including all the good stuff. But yes, it should kill the rust along with removing all infected stubble.

 

[DirtMechanic]

Yes and no. I'm not a fan of sterilization of garden soil...because it kills everything including all the good stuff. But yes, it should kill the rust along with removing all infected stubble.

Down to a certain point anyway. I find a 500,000 btu torch cannot heat very deeply, but then hours upon hours of low and slow heat would go somewhat deeper. How deep do you think the solar cleansing might go?

 

[Meadowlark]

How deep? The internet says, "typical field solarization temperature are 108 to 131-degrees two inches down and 90 to 99-degrees 18-inches deep." That's a pretty steep curve and wide range. It's not for me.