Monsanto's global biotech executive Professor Robert Reiter is also speaking, as is the United States' international biotech trade envoy, Jack Bobo.
The University of Auckland's Institute for Innovation in Biotechnology welcomed the conference with professor Joerg Kistler saying it gave New Zealand access to cutting edge knowledge.
He said genetic modification was only part of the biotech field which would boost food production.
"The reality will be at some time in the future genetically modified food is going to be much more widespread because we simply have to keep up with the hunger of the world's growing population.
"We have to be ready."
Biotech industry body NZBIO's chairman Dr Paul Tan said the conference gave Kiwi scientists and their work exposure on an international level. "Whether you are for or against it, genetic modification is a technology that you should know about."
The presence of high-profile international leaders has proved a flashpoint for opponents. Green Party genetic modification spokesman Steffan Browning said the hosting of the conference in New Zealand - and the government support - showed a "strategy" to push genetic modification.
Mr Browning last month toured the country with two Australian farmers speaking against Monsanto's involvement in agriculture. He said it was right to suspect the motives of the corporates involved. "They're not doing it just because this is interesting science."
Sustainability Council executive director Simon Terry said New Zealand needed its status as a GM-free food producer.
"They're here to sell us a story from a decade ago when there is still no product that offers real economic gains for the country, given the marketing risks."
Soil and Health Organic NZ spokeswoman Debbie Swanwick said the companies at the conference would be preaching "genetic terrorism against our food supply, economy and natural assets" . She said Monsanto was the "Darth Vader of biotechnology".
Federated Farmers vice president Dr William Rolleston said it was time for New Zealand to again debate the role genetic modification should have.
"We need to do that based on fact and not rhetoric."
New Zealand's rules governing genetic modification are currently being studied by the Ministry for the Environment.
A recently completed study, not yet released, aims to find out how much money the country misses out on because of the rules required for those working in the field of genetic modification.
The study followed work by Treasury on the issue, which linked tough rules to fewer trials and less innovation.
LEADERS IN THEIR FIELD
Dr John Bedbrook
A New Zealander and the first in the world to clone a plant gene. Now DuPont Agricultural vice-president.
Dr Richard Flavell
Leader of Dr Bedbrook's plant cloning effort. Chief scientific officer for science giant Ceres.
Prof Bob Reiter
Vice-president for biotechnology at Monsanto, one of the world's largest multinational advocates for GM.
Dr Clive James
Founder of International Service for the Acquisition of Agri-Biotech Applications.
Jack Bobo
US trade envoy for new technologies around the globe.
