big bud,auto berry, auto white widow, white widow , northern light, bubblegum, ice

hello,

it's my first outdoor grow, I grow big bud , auto berry , auto white widow, white widow , northern light, bubblegum, crystal , ice and some bagseeds in another location J

i have one strangely sick plant between of healthy plants , could some one suggest anything useful ? is there any way I can help it or it must be cute off ?