Dr Danny Donaghy is professor of dairy systems at Massey University and a specialist in pasture agronomy and physiology.
The ongoing impact on the supply of labour is also highlighted.
"In the past 12 months, an overriding concern for many growers and wineries has been the availability of overseas workers," write Chair Clive Jones and Deputy Chair Fabian Yukich in the report.
"These workers play a vital role in enabling the industry to meet the critical seasonal work peaks. If those peaks, particularly pruning and harvest, are not met this would put in jeopardy the jobs of the 21,000 Kiwis who work in and supply our sector."
The Annual Report outlines the work being done by New Zealand Winegrowers, in tandem with the Ministry for Primary Industries (MPI) and other Government departments, to secure New Zealand workers to fill the roles left by Recognised Seasonal Employer (RSE) and other overseas workers.
To read the annual report go to nzwine.com.