The project is the initiative of the Beef Returns Improvement Group - a group of Rangitikei-based farmers who investigate aspects of beef production from beef cows in hill country environments. BRIG is funded by Beef + Lamb New Zealand (B+LNZ) and holds up to four public field days a year.
Last year, the group became concerned about the impact of the plantain moth and decided more knowledge was needed. The moth is a native species, Epyaxa rosearia, and it is the caterpillar phase of its life cycle that is causing noticeable and sometimes severe defoliation of plantain in some swards over summer.
A six-month B+LNZ Farmer-Initiated Technology Transfer project is assessing the magnitude of the plantain moth problem in New Zealand, including the frequency and locations of infestations. Researchers will also be looking for correlations between severity of damage and the age of plantain swards.
A key outcome of the project will be gathering information and images for use on PestWeb, so farmers can readily identify the moth and caterpillar, as well as recognising the damage they cause.
BRIG farmer Richard Morrison has been using a plantain/chicory/clover mix for about five years, primarily for lambing multiple-bearing on to and for lamb finishing.
"My plantain paddocks yield about 14 tonnes annually, compared to 8 tonnes of grass, and the feed quality is probably 1-2 kilojoules of ME/kg dry matter higher.
"However, there are downsides to growing the mix, including the plantain moth. This is the first year we experienced the moth. It didn't touch the first-year crops, but significantly affected the second-year crops and decimated the older crops. All of the crops are next to each other, so location was not a factor. However, I believe the dry this year was an issue, as the crops were stressed and not able to 'out grow' the moth's damage."
Richard says the moth is similar to white butterflies on brassicas, in that there are a few around, then all of a sudden there are thousands and you have an issue.
"But, despite the moth severely affecting my crops this year, I am excited about the opportunities plantain can offer and I'll continue to increase its use in my system."
Plantain moth damage in crop. Photo: AgResearch