My apologies to Pioneer colleagues for bringing this up, but the final report from the Scientific Advisory Panel (SAP) reviewing the Optimum Acre-Max seed-blend rootworm refuge is publicly available.

Pioneer proposed a ~ 2% refuge (non CRW seed) mixed in each Herculex Xtra bag to reduce the current 20% CRW refuge and increase grower compliance.

Bottom line, the Panel identified many ‘areas of uncertainty’. On a positive note, they supported the concept of a seed mix in general for CRW.

However, they found ‘no evidence’ to reduce the refuge percentage. The Panel is only advisory to EPA, but its difficult to imagine the Agency going against these recommendations.

The report is long and a lot of blah-blah-blah.
I’ll summarize some of the important points so you don’t have to read it:

• The Panel was made up of scientists with expertise in genetics, entomology, IPM, crops, toxicology,and environment. One of the panelists was Dr. Jon Tollefson, now retired, the rootworm entomologist for decades at Iowa State Univ.
• Areas of uncertainty identified by the panel (technical stuff related to the toxin, genetics, and CRW biology)
  - mode of action of the CRW Bt toxin, and mortality of susceptible & heterozygous (partial resistance?) beetles
  - implications of delayed adult emergence and uneven sex ratio on development of resistance
  - frequency and type of resistance genes in the CRW population
  - adequacy of the simulation model used to evaluate the seed mix
  - the physical mechanics of mixing seed to achieve a certain % and the distribution of non-GMO plants in the field
• Some important quotes: “In general, the Panel concluded that there are uncertainties with the use of a seed blend and clear problems with reducing the refuge size. The Panel recommended additional research that would more completely examine the performance of the seed mix strategy”
• The Panel found “…no compelling evidence to reduce the proportion of non-Bt plants (either as a seed blend or spatial refuge) from 20% and there was strong concern with the request for any reduction in the refuge size with a seed blend of 5% of less. Data were not presented that supported a claim that potential yield losses justify a seed blend of no greater than 5%….Therefore the Panel concluded that, based on current science, it would be reasonable to commercially use 20% seed blend refuges while research suggested by the committee and research projects are conducted to example performance of the seed blend strategy.”
• Also, the Panel received an anonymous statement from 26 university corn entomologists which raised concern about company restriction on university research using commercially available GMO seed. The Panel specifically commented on this statement: “ …in response to two public comments, several panel members believed that access to transgenic plants by qualified researchers must be more open and transparent to maximally foster resistance management research. It does not reflect well on the biotech industry, nor does it help researchers achieve further advances in resistance management, to restrict research by public sector researchers to plant varieties that can be purchased in the open market.”

For those of you wanting light holiday reading, here is the link to the EPA web site with the report.

Under final meeting minutes, click on the pdf icon to open the minutes.

SOURCE: Chris DiFonzo, MSU