BD#501 should be been used after using BD#500.
Horn silica (501) stimulates photosynthesis and the ripening process, regulates leaf growth, and enhances flavor and storage quality.
How to use BD #501 (5x) Stir vigorously for Twenty minutes in enough water to meet your application requirements. Apply immediately to foliage or ripening fruit. Apply periodically during the growing season. One unit is enough for one acre when stirred properly. Spray in the early morning.
For additional information, visit: JPI Preparation Articles ; Instruction Handouts
Additional Article: Brief Instructions: 500, 501, 508