I bet your fertilizer is 10 times stronger than it should be. Black root tips are a sign of chemical damage. Use the calculator on Ray's site to figure out how much to use for 20 ppm N. You'll be surprised how little you need - and how much you've been using.
Thank you so much, im gonna check Ray's site now, thanks again...LORENA
Last edited by lorenaguti; 05-14-2014 at 10:48 PM..