I successfully triggered ascochyta leaf blight, and proved how useless fungicides are against it
(Firstly, a single experiment doesn't prove anything. It's just a good demonstration... Extensions have long since proved it)
Background:
Had a 10 day stretch with no rain or irrigation. My kbg was doing weirdly well, despite growth potential getting into the teens for several days straight... Darn clay holds water too well.
This section along the driveway was starting to wilt a bit faster because it's got a deep sand base from the driveway. So it's hot and dries out faster. Still green, but it was getting that dark dull hue of drought stressed grass.
This spot gets about 80% sun.
What I did:
Saw we had some rain coming the next morning. So I applied propiconizole, chitosan oligosaccharide, azoxystrobin, and chlorothalonil (for science 😉). Let it dry for a few hours.
Next I hand watered slowly for 20 minutes. Just a slow but really heavy drench.
Then I took a leaf blower and dried off the foliage and stems... This is the step that essentially guaranteed ascochyta would be favored over any other disease (assuming the fungicides didn't do that already), by kicking up any dormant ascochyta spores and avoiding the leaves being wet *all* night.
Rain came over night. Didn't check the totals, but it was plenty.
Next day was sunny and still warm. Gave it 2 light midday mistings to ensure the results weren't obscured by heat triggering actual dormancy.
Leaves began going more brown.
After the syringing, I did another bit of chlorothalonil because I assumed it was probably all washed off by that point.
More rain over night.
Next day, it was all a sickly gray.
2 more midday waterings.
Rain in the morning.
Next day (today) it's in full blown ascochyta breakout. Active lesions on everything, confirm ascochyta pycnidia under microscope. The effected area perfectly aligns with the spots that were hit by the blower.
Neat!