What can be done to rid it from your vegetable garden
There is no easy answer, blight is not just one pathogen, but there are specific disease organisms and insect pests that attack different host plants, so there is no one cure to fit all.
Plant health and resistance to pests and diseases can be addressed in a general way by improving soil fertility and with good water management.
Specific plant problems need to be identified and managed with specific bio-pesticides. The one general purpose insecticide, miticide and fungicide is 70% neem oil as a foliar spray. This is organic program compatible because it biodegrades and is not persistent in the environment. But to be effective, it has to be sprayed every two weeks for preventive treatment. Active, advanced infections are hard to control and reversal of damage is usually not possible. Prevention of spread and of new infections is what you can shoot for.