Papua New Guinea's agriculture export income in 2015 was less than half of 2011 levels, according to Bank of Papua New Guinea data.
Business Advantage PNG reported income from palm oil exports was at its lowest level since 2009, while coffee exports were below half the value of four years ago and income from rubber exports almost halved over a year.
The drop is partly attributed to lower export prices, but also to significantly lower production levels.
The Bank noted the decline in coffee exports, which accounted for 29 per cent of PNG's agricultural export income last year, was linked to lower yield from ageing and rehabilitated coffee trees, and the impact of the El Niño drought.
With the exception of logs, the weighted average kina price of agricultural and marine product exports declined by 5.9 per cent in 2015, compared with 2014.