Question

اين گل رو آفت زد و خشك شد ، به انگليسي چي ميشه؟

Answer 1

The flower was infected (e.g. with fungi) and dried/withered/became dry.

Perennials [a category of flowers] that are commonly infected include delphiniums, lungwort, bee balm...

http://www.gardeners.com/how-to/common-flower-diseases/8109.html

Infest is also possible but it usually goes with trees rather than flowers.

Comments

infect involves viruses or germs while infest is about insects or animals (like rats). Generally the second is not the case for flowers.

Answer 2

Blight is a disease which makes plants dry up and die.