I found a product label for this stuff, but it does not list the ingredients. It's probably only available in canada; I think US formulations must list the ingredients.
http://www.growercentral.com/index....ls&familyID=260730&CFID=5878331&CFTOKEN=12339
This is an acidic fertilizer, and carries a pretty strong label for that purpose. It's label even indicates that it is well suited for acidifying irrigation water, but it includes the warning to run clear water for 10 minutes to wash the fertilizer off the foliage. It does not mention any use for soil injection on trees, and the concentrations that it suggests using are too dilute to provide lasting benefit to trees, unless you did it once every two weeks, as suggested.
I suspect that product could really be a problem for some plants. It lists 16% potassium nitrate in the MSDS, and that is a really "salty" product, although it would be readily available to the plant. It also calls for a pretty low applied concentration, and is clearly not safe to use if improperly diluted. Quote:
[To fertilize with 100 ppm Nitrogen, add 48g Plant-
Prod® 21-7-7 to 100 L of water; for 200 ppm Nitrogen,
add 95 g to 100 L of water.] For an english conversion at the stronger concentration, that is 3.35 oz (about two shot glasses of product) in 27 1/2 gallons of water.
Most soluble tree fertilizers I have used call for one 20 lb bag per 100 gallons of water: MUCH stronger and probably made up of chemicals that are not quite so "hot". If you mixed this stuff up that strong, I would suspect that was your problem. When I mix up a liquid lawn fertilizer application, I routinely add 350lbs of urea, 100 lbs of urea formaldehyde, and 50-100 lbs of potassium sulfate per 500 gallons of water. I have not found a soluble source of phosphorus that is safe and economical. This mixture is a little bit salty, but not so strong that it will cause foliage burns unless applied in the summer heat. The product you used does not sound safe at those application rates.
Next time you do some fertilizing, read the label very carefully to see that the products are not as harsh to the plants.
For the most part, any chemicals used to fertilize plants that have words in them like ammonium- , -chloride, -nitrate are pretty salty. Use lower doses for greater safety. The acidity of any chemical is quite a bit more complex, and you should just read the label carefully.
Organic compounds like urea must be decomposed by bacteria (or others) in order to be taken up by the plant. The organic compounds are much safer, and less likely to cause pH problems or salt burns. When I say "organic", I am refering to "organic chemistry" which has ABSOLUTELY NOTHING to do with "organic farming". It's just one branch of chemistry that usually involves itself with complex carbon compounds, rather than "inorganic" compounds like potassium nitrate.