Planted golden wonder potatos issue

I planted golden wonder potatos I would say 2-3 weeks or so ago they broke ground about about 4-5 days ago but this morning some of the youngest leaves at top have went brown, is this just leaf scorch because its been so sunny or is it the dreaded early blight. The soil isn't dried out or soggy and is in a site that gets full sun most of the day and is a well ventilated open site, I did water then the other evening

 

It was pretty chilly overnight for the last few nights here. Could have been a touch of frost. It's best to keep them well earthed up until the risk of frost is past (late May here).

 

Frost

that variety makes amazing chips

 

My first earliest got frost, we had two frosty nights in the last few days. The second earlies broke ground earlier but have withstood it, i assume as the shoots weren't as tender or the variety can resist it slightly more. They go dark green then brown when they get frost

 

They will grow back , but put them back a tad