Looks like slugs have been at my chard - under agribon 19.
How to prevent this next year....
If you eat eggs you might want to put the shells in the oven and dry them out then crush them up then place them around your plants for protection.
So far, my best defense has been shredded or screened compost. Spread about 1/2" deep around the plants. The top bit dries out very quickly. sun goes down, slugs come out, slugs crawl on compost and it sticks to their slimy little bodies... they can't lay down a slime trail so they can't move. Sun comes up, slugs can't run... et voila - escargots. Works really well with baby beans - a hungry slugs favourite food. If it rains, fluff the compost up a bit or add a bit more. You can never have too much compost in your garden
Here is a link that might be useful: Lively Dirt - The Garden Blog
What about using beer in tuna cans?
Bury the can up to its rim beside the plant, fill with dark beer, and the slugs will come to party and drown.
You can also place boards here and there in the garden and in the morning, they'll be hiding beneath. Time to squish.
To round them up at nite, go out when dark with a flashlight. When you find one, squish.
Better luck this year.
Been fighting slugs for years. BEST method I've found is: put some cornmeal in a small bowl set where you've seen slugs. (heck, put out lots of small bowls) Slugs love it. Next morning bowl (s) will be full of dead slugs. Have no idea why it kills them.
Bye the way, Mes-ca (sp) which is Mexican cornmeal ground to a fine powder doesn't seem to work.
Second best method: hehe last years heat wave and no rain had a silver lining. I couldn't find one lousy slug on my night walks.
Why not use Sluggo or Escar-Go!?