Protesters have stepped up their campaign
Robin Harper was due to meet demonstrators at the GM protest camp at Munlochy on the Black Isle. They have kept a vigil for the past four months.
The camp, situated next to a government-approved test site for GM crops, won permission from Highland Council to have a permanent presence outside the farm on Tuesday.
Demonstrators were given planning permission for their camp, which consists of a caravan, toilet and three parking spaces, on a council-owned lay-by outside Roskil farm.
The modified oil seed rape crops are part of the second round of testing at the farm by research firm Aventis, which began in March 2000.
The MSP, who has introduced a Bill in the Scottish Parliament to promote organic produce, called for a ban on the trials until further research has been carried out.
He said: "I've visited the Munlochy vigil before and I'm delighted that they have been granted permission to stay, this will make sure that the pressure is kept up so that the testing of genetically modified crops in the countryside can be halted.
"I am concerned that the testing of GM crops in the area does not damage the potential there is for organic food and farming."
Mr Harper was also due to meet farmers and producers in the area when he addresses the annual general meeting of the Highlands and Islands Organic Association at Fort George.
Scottish Rural Development Minister Ross Finnie welcomed in September a report which dubbed GM crop trials in the UK as "seriously deficient".
Mr Finnie said the report, by the Agriculture and Environment Biotechnology Commission (AEBC), was "hugely helpful".