These products are essentially Manganese sulphate with added adjuvants to aid in mixing and to give improved plant uptake.
The absolute quality is determined by the source of Manganese sulphate and some very cheap product use Chinese with all its consequent draw backs. Even products made from the higher quality sources do not contain sufficient levels of adjuvants when compared to good quality liquids. The best dry flowables are soluble granules which are impregnated with adjuvants, agglomerated and dried as true granules (1 - 2 mm). However, the process is expensive and the adjuvant content is still insufficient.
Dry Flowables should not be put through induction hoppers on sprayers and still exhibit some of the compatibility problems associated with straight Manganese sulphate.
Manganese sulphate
Declared at 30% Mn
Quality determined by raw material source
Added adjuvants but low levels of inclusion
Some improvement in uptake efficiency
Some compatibility problems
Difficult to add to induction hoppers on sprayers
Dust hazard
Risk of crop scorch