Answers to all your frequently asked questions
Quickly link to the questions...
- What is an endophyte?
- What is a novel endophyte?
- How long has AR37 been commercially available?
- Why use AR37?
- Who should use AR37?
- Will AR37 solve my pasture persistence issues?
- I’ve heard AR37 is bad for my stock?
- How should pasture with AR37 be established?
- How good Is AR37 endophyte?
What is an endophyte?
An endophyte is a fungus that lives inside a grass plant. This relationship is symbiotic, i.e. both the endophyte and the plant benefit from it. The grass gives the fungus a place to live, food, and a way to reproduce, while the fungus gives the plant protection, (in the case of AR1 and AR37) from insects. An endophyte is essentially an ‘in-built insecticide’.
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What is a novel endophyte?
A novel endophyte is a naturally occurring endophyte that has been identified as having properties that make it more useful in agriculture than other (‘standard/high’) endophytes. These properties usually include better insect protection for its host plant, and /or reduced side effects on grazing animals, e.g. AR1, AR37, MaxP®, Endo5.
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How long has AR37 been commercially available?
AgResearch together with its commercial partners began work on developing the AR37 endophyte in 1995. Ryegrasses with AR37 endophyte were released commercially in autumn 2007.
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Why use AR37?
AR37 is the most recent endophyte to be released from AgResearch, and has been widely tested by AgResearch as well as in a three year trial by DairyNZ. AR37 gives a level of protection against insects better than any other endophyte.
Plants with the AR37 endophyte have protection, once established, against adult Black Beetle, Argentine Stem Weevil larvae, Root Aphid, Pasture Mealy Bug and Porina. These insects all have a strong role in a reduction in the productivity and longevity of the ryegrass.
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Who should use AR37?
Farmers who want improved pasture production, persistence and animal performance from their pastures should use AR37, especially where damaging insects are likely to be present. Trials that have been undertaken show that AR37 is a suitable pasture for dairy cows, sheep, and beef animals.
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Will AR37 solve my pasture persistence issues?
There are many factors involved with pasture persistence including correct pasture establishment, over grazing, stock damage, insects and soil health to name a few. AR37 endophyte will reduce the effects that insects play in the reduction of pasture persistence, but if there are other factors involved it will not stop pasture loss
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I’ve heard AR37 is bad for my stock?
In a three year DairyNZ grazing trial, milk production from AR37 and AR1 pastures was not significantly different, on a whole season basis, in any year. Lambs grazing AR37 ryegrass have very good production but this production can be reduced in the event of ryegrass staggers.
AR37 can cause ryegrass staggers. Trials have shown that on average the frequency, duration and severity of ryegrass staggers is less than for standard endophyte. However on occasions sheep (and potentially other animals) grazing AR37 ryegrass may be severely affected.
After many years of use on commercial dairy farms, ryegrass staggers have not been observed in dairy cows on farm to date.
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How should pasture with AR37 be established?
As with new AR1 endophyte pastures, all existing ryegrass plants should be removed from the paddock (using spraying and/or ploughing), and old ryegrass seed buried or germinated (following multiple spray applications or cropping) before planting ryegrass with AR37. Re-establishment of old ryegrass plants will not result in failure but can reduce animal performance (if old ryegrass has standard endophyte), pasture production and possibly persistence.
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How good Is AR37 endophyte?
AR37 endophyte is the best endophyte for insect protection and ryegrass yield. AR37 endophyte is widely tested and has resistance to more insects than any other commercially available endophyte. AR37 endophyte provides ryegrasses with much better drymatter production and persistence than any other commercially available endophyte.
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