Dromgool, 27, works at The Landing on Purerua Peninsula and has his own vineyard near Waipapa growing a wide variety of grapes. He produces wine under his own 144 Islands label.
Dromgool admitted to some nerves but was also looking forward to defending his title and having fun.
''It would feel very special to win the title in a year that means so much to Northland — but whoever wins it'll be a great opportunity to bring our story to the nationals and fly the flag for Northland.''
Contestants will be tested on pruning, trellising, pest and disease management, soil nutrition, wine appreciation, accounting and budgeting. Around noon contestants will race each other to complete a series of tasks in a ''hortisports'' challenge; they will also have to give a speech during the awards dinner that evening.
Competition coordinator Nicky Grandorge said it was ''extra special'' to hold the competition in Northland in the 200th anniversary year of New Zealand's first grapevine.
The competition had been running for 14 years but this would be only its fourth year in Auckland-Northland.
Past national winner Tim Adams, of Waiheke, said Northland and Auckland produced only 3 per cent of New Zealand's wine output, and Northland accounted for only a tiny share of that.
The quantity was small but the North had a huge focus on quality, boosted by a strong tourist market, he said.
Dromgool said Northland viticulturists faced challenges from cyclones and other extreme weather events but the region's warmth and maritime climate meant they could do things that were impossible elsewhere in New Zealand.
Marsden Estate wine-maker Rod McIvor hoped high school students thinking about careers in viticulture would come along on the day.
