Sickly Victorian child making me look bad

what ails my son? why is he not strong and beautiful like his brothers and sisters? a touch of consumption perhaps?

Nah but really, why does one of my plants look like this? It has been droopy and crispy for weeks. It's still growing, flowering, fruiting, but looks absolutely ghastly while doing it. It is on the same exact watering and fert regimen as my other 7 plants and they are all doing great.

if it weren't my only wild boar farms atomic grape I'd just throw it out, but I want those maters :(

Please help my son. Is he diseased or something? is he stupid?