Dilmah is also heavily involved in conservation in Sri Lanka and the founder's MJF Charitable Foundation, funded by Dilmah profits, works across the country currently serving 10,000 people each week.
Son Dilhan Fernando, and chief executive of Dilmah Tea, said the doctorate is a fitting tribute to their father on the eve of his 90th year.
"It is outstanding that [Merrill] is recognised for the incredibly positive outcomes of the philosophy of making business a matter of human service and his love for New Zealand.
"Taste, Goodness and Purpose are the three elements that are at the heart of Dilmah. We are formed on a sincere commitment to a humanitarian and environmental purpose and it is our earnest wish that all business leaders will understand that this is an irrevocable commitment. We continue to work towards reducing inequality and mitigating the worst effects of global warming."