Herbicide injury – some varieties are sensitive to herbicides. Sinbar (terbacil) is likely to cause marginal burning, as is Princep.
Sinbar may cause leaf yellowing and/or bleaching though usually accompanied by leaf burning/browning.
If leaves also have a yellowish orange powder on their undersides of leaves, this indicates late leaf (yellow) rust.
If root uptake occurs, veinal or interveinal yellowing/necrosis also may occur.
