Frequently Asked Questions about GrubOUT® U2

Cropmark Seeds have compiled a list of the frequently asked question about our GrubOUT® U2 endophyte...

What is endophyte?
The common endophytes of grasses are fungi that exist symbiotically within grass plants, living between cell walls of the plants. The endophytes produce compounds called alkaloids which can provide the host plant with varying degrees of protection from insect attack.

However, some of these alkaloids can have negative effects on grazing animals, such as grass staggers, heat stress and reduced livestock performance.
The naturally occurring endophyte is called the standard endophyte, feral or wild type endophyte.
Over recent years, scientists have developed a range of ‘novel’ endophytes in an effort to minimize the negative effects on livestock. These endophytes include AR1, AR37, Endo5, NEA2 and MaxP.

The plant protection against insect pests, and animal safety of these endophytes varies between endophytes and is dependent on the host plant.
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What are lolines?
Lolines are a unique group of alkaloids found in some strains of endophyte infected meadow fescue and some other grass species. Loline alkaloids have insecticidal properties and act as feeding deterrents to insect pests, but are safe to sheep, cattle and deer.

Unlike some alkaloids found in the other commercially available endophytes in perennial ryegrass, lolines can be present below and above ground, providing protection of the host plant against top feeding and root feeding insect pests.
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How does GrubOUT® U2 protect host plants against insect pests?
The lolines contained in GrubOUT® U2 act as feeding deterrents. Insects do not like eating grasses containing the endophyte. As lolines can be present throughout host grasses, they can provide above and below ground protection against insect pests.

GrubOUT® U2 will provide improved protection against grass grub larvae, black beetle adults and larvae, porina caterpillar, black field cricket, Argentine stem weevil, and red headed pasture cockchafer. Other research evidence suggests that GrubOUT® U2 will also protect against the pasture mealybug, root aphid and soil nematodes.
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Why are insects still present in the soil under GrubOUT® U2 pasture?
The lolines contained within GrubOUT® U2 are feeding deterrents. Being a feeding deterrent, insects don’t like eating the host grasses, instead feeding on other species within the pasture, including other grasses, clovers and weeds. GrubOUT® U2 containing pastures can still host populations of insect pests, and will persist in spite of those populations.
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Does GrubOUT® U2 affect earthworms?
There is no evidence to suggest that the loline alkaloids which are found in GrubOUT® U2, have any effect on earthworms. Anecdotal evidence from trials that Cropmark Seeds has conducted, shows good healthy populations of earthworms under GrubOUT® U2 containing pastures.
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Is GrubOUT® U2 safe for livestock?
The lolines contained in the GrubOUT® U2 endophyte have been the focus of considerable research worldwide. There are no known reports of lolines having a negative effect on the health or performance of ruminants (sheep, cattle or deer). Research would indicate that the GrubOUT® U2 endophyte is safe to ruminants and that it will not cause grass staggers or heat stress.
Research into safety with horses continues. At this stage we are not recommending the use of the GrubOUT® U2 endophyte for horses.
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How stable is the GrubOUT® U2 endophyte in seed?
Endophytes are living organisms. Within the seed, the endophyte can deteriorate over time. High temperatures and high humidity such as experienced over the summer months, can also kill the endophyte. Some endophytes are more stable than others within the seed.
Our research would indicate that GrubOUT® U2 is a relatively stable endophyte. Irrespective, GrubOUT® U2 seed requires cool storage if kept for extended periods, particularly over the warmer summer months. Cropmark Seeds cool-stores its seed containing GrubOUT® U2.
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Will the endophyte disappear from the plant?
No. Once the endophyte is established within the plant, it will normally remain in the plant for the life of the plant; unlike in seed, where it can deteriorate over time.
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Will the endophyte transfer to other plants within the pasture?
No. The endophyte grows up between the cell walls of host plants. They will not transfer to other plants within the pasture, be they grasses, clovers or other species.
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Why do I need treated seed?
Endophytes are not fully established within the plant until about 6-8 weeks after
germination of the seed, and therefore don’t provide any protection against insect pest until then.

Consequently seed treatment is required to provide protection to the plant against some insect pests.
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Is there data available to support the claims Cropmark Seeds is making?
Yes. All claims made by Cropmark Seeds in relation to the GrubOUT® U2 endophyte, or the loline alkaloids it contains, are based on credible research and trial results. The majority of this is via peer reviewed, published papers in science journals, making it as ‘rock-solid’ as possible.

A list of some of the more relevant published research papers is attached under the bibliography section of the research section of this web site.
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Can I reproduce seed for sale?
The GrubOUT® U2 endophyte is protected by NZ Plant Variety Rights, grant number 2716.

It is an offence to reproduce GrubOUT® U2 containing seed and sell, barter or trade it.

Seed testing systems are now sufficiently advanced to quickly and easily detect if seed contains GrubOUT® U2 endophyte. Offenders will be prosecuted.
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Plant Variety Rights and Intellectual Property
Cropmark Seeds Ltd owns all rights registered in New Zealand under the Plant Variety Rights Act 1987 for GrubOUT® U2, together with all copyright, trademarks and other intellectual property rights (whether capable of being registered or not in New Zealand or any other jurisdiction). We reserve all rights in this respect.
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Whilst we have used all reasonable endeavours to ensure the information contained here-in is based on current and accurate research and research findings, Cropmark Seeds Ltd cannot provide a warranty to such effect.

We will not be liable for any claims, damages, losses (including without limitation, loss of income, profits, savings, goodwill or business opportunity), costs or expenses of any kind, or for any direct or consequential losses which arise from the use of any seed supplied by Cropmark Seeds Ltd.
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