"I was unaware as to what was going on at that portion of the plot or [for] what purpose the big corrugated iron shed was used by the person or persons who leased it," he said.
Mangena, 60, was arrested last week along with Morena Maqoaelane, 26, William Kazipata, 34, and Kennedy Tsogolane, 24. Police raided the farm after a three-week observation by the Hawks, crime intelligence and anti-gang unit.
The drugs-manufacturing barn was situated in the farm which also has chickens, goats, cattle and ducks. Inside the barn police said they found a spillage dryer tank, gas cylinders, plastic drums and a number of zinc basins full of chemicals which were allegedly used to produce mandrax.
Police said the drugs were produced on the farm but not packaged on the plot. They said at the time of arresting Mangena that electronic and physical surveillance were carried out on the property and modus operandi of the suspect "fully identified".
Mangena told the court he has surrendered his passport. He has to report to Booysens police station every Monday between 6am and 6pm.
He is also not supposed to have any form of contact with any of his neighbours, workers or any local community member in Hillside.