Do GE Crops Really Produce a Higher Yield?

• Author: Benbrook, Charles
• Position: Genetically engineered crops - Brief Article

The evidence is now overwhelming and indisputable that average yields of Roundup-ready (RR) varieties are about 4-6% less than conventional varieties. The definitive and most recent comparative analysis was carried out by Dr. E. S. Oplinger of the Univ. of Wisconsin, Madison, who has managed a North Central regional project assessing soybean varietal performance for years. Dr. Oplinger compared yields of 5,172 conventional varieties paired with 3,067 RR varieties in eight states in 1998. The RR varieties yielded between 86% and 113% of the conventional, and average yields were 96% of conventional. There were just two areas where RR did better--Illinois and southern Michigan. Outside these areas the average yield drag was greater, on the order of 6% to 8% (data from "Performance of Transgenetic Soybeans-Northern US," Dr. E.S. Oplinger, M.J. Martinka, & K.A. Schmitz, Dept. of Agronomy, UW-Madison).

This places the minimal average yield drag at about two bushels per acre, or $10.00 (and it was much more on many farmers). That $10.00 plus the technology charge, plus the 2 to 3 applications of Roundup (not the one application which Monsanto alleges), plus the 2 or 3 other herbicide that must be applied make for the most expensive soybean seed-plus-weed management system in modem history--between $40.00 and $60.00 per acre depending on rates, weed pressure, etc. Not long ago, in 1985, the average seed-plus-weed costs on farms in Illinois was $26.72 per acre (USDA cost of production data), and represented 23% of total variable costs; now, they represent 35-40%. No wonder Monsanto is throwing in free resprays and replanting, and other crop insurance-like benefits as an added bonus.

Every independent set of data I have seen reaches the same conclusion: the technology increases costs somewhat, but imposes a "price" farmers are willing to pay for the simplicity and robustness of the weed management system. They will also sacrifice some net income per acre. This is a perfectly rational...