Whoa, I've missed this thread for a while!
No manure from a nursery will not burn your plants as it is usually composted but, check just to be sure.
Fish emulsion is good stuff as well.
A lot of people like to use epsome salts but, as you all know I'm an old organic and I don't like to add straight salts to my plants because they can burn the plants and they also kill beneficial soil biota and beneficial biota that live on the leaves and stems of plants.
What works really well is to brew compost tea from non sterilized compost in a 5 gallon bucket with a little aquarium pump and use that as a foliar spray. The tea will add nutrients to the plant but, more importantly it will add beneficial biota that will eat any disease causing organisms.
The tea should not smell bad, if it does; discard it.
Feed the soil, not the plants.