Dr David Askin of Kilu Consulting (New Zealand) said sweet potato weevil is the worst insect pest of kaukau that ruins storage roots (tubers) which rot with bitter taint.
Kaukau is the most important food crop in PNG with over 60% of the total population depending on it.
Dr Askin said when kaukau is infected with the weevil's larvae, even pigs won’t eat the storage roots.
His advice comes at a time when there are reports of the weevil causing great harm in PNG gardens, especially when communities are slowly recovering from food shortage caused by the drought.
"There is no easy way to control sweet potato weevils. However there are a number of things gardeners can do to reduce weevil damage," said Dr Askin, who is based at Wapenamanda in Enga under a climate change adaptation program through the New Zealand Government.
Some of the cultural weevil management practices recommended by Dr Askin include:
• Crop rotation - kaukau rotated with other crops in a particular area over two-year time interval,
• Use of live fences in slowing down the movement of flying weevils from an area full of weevil into another area with crops other kaukau over two year-interval,
Farmers have been advised to practice cultural control methods of the disastrous sweet potato weevil as they recover from the El Nino drought.
"Although there is no effective method to manage the weevil, the impact can be minimised if farmers follow these steps," Dr Askin said.
Dr Askin has had many years of experience in PNG agriculture. He was one of those who introduced rabbits into PNG in the early 1990s through Unitech.