Understanding Corn Traits
One year ago I wrote a blog post titled “Understanding ‘Stacked’ Corn”. Since then the corn trait market has expanded and is now even more confusing. In the beginning, 1996, there was only Bt corn. The bacteria Bacillus thuringiensis, is inserted into corn plant tissue. When a insect eats the corn plant tissue, the Bt protein binds to the intestinal wall and causes holes to form. These holes spill gut fluid into the insects abdomen cavity, killing the insect. Since 1996, the corn trait market has expanded to include above-ground and below-ground insect protection and herbicide resistance. Here is a brief overview of each trait which is currently on the market.
1. RoundUp Ready(RR) or Glyphosate Tolerant(GT) – crops with this trait are able to withstand a herbicide application of glyphosate. The RoundUp Ready trait was developed by Monsanto.
2. Liberty Link (LL) – crops with this trait are able to withstand a herbicide application of glufosinate. Glufosinate is sold by Bayer CropScience as Ignite. The Liberty Link trait was developed by Bayer CropScience.
3. Herculex I – This trait was developed by Dow AgroScience and protects against most corn borers, fall armyworm, plus it suppresses corn earworm. This trait also includes Liberty Link and the option to add on RoundUp-Ready genetics. Refuge acre requirements are 20% of acres in corn regions and 50% of acres in cotton regions.
4. Herculex RW – This traits provides protection against western, northern, and Mexican Corn Root Worm and is a Dow AgroScience trait. Refuge acre requirements are 20% of acres in all regions.
5. Herculex XTRA – Combines the genetics of Herculex I and Herculex RW to provide both corn borer and corn rootworm control. This trait also suppresses corn earworm and was developed by Dow Agroscience. Refuge acre requirements are 20% of acres in corn regions and 50% of acres in cotton regions.
6. YieldGard VT Triple – A trait developed by Monsanto that provides protection against various corn rootworms and corn borers, plus fall armyworm, wireworm, white grubs, seed corn maggots, early flea beetles, and corn earworm. This trait is stacked with RoundUp Ready genetics and requires 20% of acres be planted with refuge corn.
7. Genuity VT Double Pro – This trait, developed by Monsanto, is advertised as having “dual modes of action for above ground protection to control more primary pests.” This trait provides protection against corn earworm, fall armyworm, and corn borers. This trait is stacked with RoundUp Ready genetics. Refuge requirements for this trait are 5% of acres in corn regions and 20% of acres in cotton regions.
8. Genuity VT Triple Pro – This trait is promoted by Monsanto as being “the industry’s first dual mode of action above-ground insect protection in corn that is stacked with below-ground insect protection and RoundUp Ready technology.” Basically these traits provides protection against corn borers, fall armyworm, corn earworm, corn rootworms, and secondary soil pests. There is a 20% acreage refuge requirement in all regions.
9. Genuity SmartStax – This trait combines genetics from both Dow AgroScience and Monsanto. It is a combination of YieldGard and Herculex technology, plus Liberty Link and RoundUp Ready genetics. Provides protection against: corn borers, corn rootworms, wireworm, seed corn maggot, black cutworm, western bean cutworm, corn earworm, and fall armyworm. This trait requires 5% of corn acres be planted as refuge acres.
10. AcreMax 1 – This is a complicated trait. It was developed by Pioneer Hi-Bred and is marketed as the “first insect control solution, allowing growers to simplify and reduce their corn rootworm refuge by placing the refuge in the bag.” This trait provides protection against corn borers, fall armyworm, western bean cutworm, and larval protection against corn rootworms. The complicated thing about this trait is associated with refuge acres. The manufacturer includes the corn rootworm refuge in the bag, however the producer still has to plant 20% of their acres as refuge for corn borers.
11. Intrasect – This trait, developed by Pioneer Hi-Bred, is a combination of Herculex I and YieldGard corn borer traits. Refuge acreage is reduced to 5% in corn regions and 20% in cotton regions because of the different modes of action the corn borer traits provide.
12. Agrisure 3000GT – This is a trait developed by Syngenta that protects against corn borers and corn rootworms. In addition this trait offers Liberty Link and Glyphosate Tolerance genetics. Refuge requirements are 20% of acres in corn regions and 50% of acres in cotton regions.
13. Agrisure Viptera 3110 – This trait only provides protection against corn borers, fall armyworm, and corn earworm. It was developed by Syngenta. Producers can add on Liberty Link and/or Glyphosate Tolerance genetics. 20% of all acres need to be planted as refuge acres.
14. Agrisure Viptera 3111 – This trait combines the Agrisure Viptera 3110 traits with corn rootworm control. Producers have the option of adding on Liberty Link and/or Glyphosate Tolerance genetics and 20% of acres need to be planted as refuge acres.
You can see why understanding corn traits is so complicated. There are so many options and different traits that control the same pest. Always make sure you read the tech agreement and plant the appropriate amount of refuge acres. These acres are important to reduce the chances of corn insects developing a resistances to the genetic traits we use to control them.
