Many customers have asked us about reducing blossom end rot in tomatoes and peppers. The number one cause is a deficiency of calcium and magnesium. Using Cal-Max in your regular feeding program will not only reduce blossom end rot, but also help eliminate leaf yellowing and premature bud dropping off. Can be used as a liquid feeding of a foliar spray. 1 Litre. Analysis: N - 2% Ca - 3% Magnesium Mg 1% Iron Fe 0.1%.