Hi Konrad,I think you have both factors in play here.Scurf (
Monilochaetes infuscans), a fungus, is quite common in PNG, particularly in areas that have very short crop rotations. In some areas of Eastern Highlands, it is so common that I have had farmers tell me it is a sign of maturity. Usually it is restricted to the skin, so is more a visual effect. Spread is often through infected planting material, something that I have clearly noticed in trials comparing pathogen tested vines and field collected vines. It survives in the soil for 1-2 years. The post-harvest handling of sweetpotato in PNG is terrible. Roots are thrown around, packed as tightly as possible into unventilated 80+ kg woven plastic stock feed bags. These are then manually lifted on and off trucks a number times. If going to Port Moresby they are then loaded into shipping in containers and then unloaded and transferred to storage depots before being reloaded and distributed to sales points. There are levels of damage at all points along the supply chain.CheersMike
Michael Hughes
Farming Systems Development Officer,
Department of Agriculture and Fisheries
Please note changed office telephone numbers.T 07 4017 0716 M 0427 602 156 International +61 7 4017 0716 / +61 427 602 156
E michael.hughes@daf.qld.gov.au
W www.daf.qld.gov.au
28 Peters Street, Mareeba Q 4880