Prices on world markets for New Zealand's commodity exports fell for the sixth consecutive month in September.
But a weakening in the currency over the month pushed returns to producers up slightly.
The ANZ's monthly index of prices fetched on world markets fell 1.3%for commodity exports in September.
Prices for 10 of the 17 commodities the bank follows fell during the month - including dairy products, meat, wool, apples and kiwifruit. Seafood edged up slightly.
It was a different story once the weakening in the New Zealand dollar was taken into account, with the currency falling 1.1% during the month.
That helped push up New Zealand dollar returns to exporters 0.4% during September - the first monthly increase since March this year.
ANZ rural economist Con Williams says farmers increased their production earlier this year in response to the higher prices and that increase in supply has led to the moderation in prices.