Yield and efficacy aata reinforces consistency of Dow AgroSciences SmartStax

With more than 80 percent of its yield data now available, Dow AgroSciences SmartStax® technology has proven that it is delivering higher whole-farm yield potential to growers when compared with other trait technologies that are available in the market.

"Weve run a battery of trials comparing hybrids with the same genetic packages that contained either SmartStax trait technology or Herculex® XTRA Insect Protection. Weve also worked with key universities to evaluate the performance of SmartStax against corn pests. We are extremely pleased with the consistent, positive performance of Dow AgroSciences SmartStax," says Casey Onstot, traits marketing manager for Dow AgroSciences.

2010 Dow AgroSciences data, gathered in collaboration with Iowa State University, University of Illinois, Purdue University, University of Nebraska, and South Dakota State University, showed that SmartStax® provided consistent protection against western corn rootworm, the major below-ground corn insect. The studies were conducted under medium to high insect pressure (Figure A), as well as low pressure (Figure B), and results showed very consistent, effective protection provided by the SmartStax technology compared with non-Bt hybrids.

Researchers monitored the rootworm damage using a node injury scale developed by Iowa State University. In the scale, 0.00 represents no root damage, and a value of 3.00 is the highest damage rating, indicating three nodes or circles of roots have been destroyed by rootworms. In all trials, Dow AgroSciences SmartStax hybrids showed root injury of 0.05 or less.

"An injury rating of 0.25 indicates that a quarter of a node has been eaten. This is the level where yield damage starts to occur. Plants with node injury ratings of 1.00 or higher are more susceptible to lodging and further yield loss," says Bill Hendrix, Dow AgroSciences North American biology team leader for insect management traits.

Researchers also examined efficacy of Dow AgroSciences SmartStax for above-ground insects. Preliminary results from 2010 field research trials show that the SmartStax technology provided consistent control of western bean cutworm (WBCW) and corn earworm (CEW) across multiple locations offering superior control compared with the non-Bt hybrids.

For the above-ground insect studies, the field scientists analyzed the amount of ear damage incurred by various pests. One square centimeter is equal to 4 to 6.25 kernels damaged. Five square centimeters is equal to 100 to 156.25 kernels damaged. This measurement demonstrates how quickly insect damage can decrease yield.

In the CEW studies under heavy pest pressure, 3.9 square centimeters of non-Bt corn ears were consumed, 2.5 centimeters of ears with Herculex® XTRA Insect Protection, and only 0.4 cm of ears with SmartStax (Figure C). The data represents trials in Indiana, Illinois, Iowa, Pennsylvania and Louisiana.

In similar trials, university and Dow AgroSciences studies examined the amount of ear consumed by WBCW under high pest pressure. Compared with first-generation and non-Bt hybrids, the SmartStax hybrids displayed outstanding, consistent protection (Figure D). The data includes trials in Indiana and Nebraska.

"Western bean cutworm has expanded its area of infestation into new geographies each year. It can cause significant damage and wreak havoc on yield. As the risk of western bean cutworm expands, additional growers will count on the protection offered by SmartStax," Hendrix says.

Solid, consistent performance is meeting grower expectations, as well. Joe Dotterer from Bloomfield, Iowa, was pleased with his first experience with SmartStax. "Dow AgroSciences SmartStax performed well. The emergence was very good. The insect pressure was basically nonexistent. We didnt have any problem with lodging – the standability was very good, and we were pleased with the yields that we had on our farm," he says.

Grower Bob Larson of Creston, Neb., notes that the value of the reduced refuge – only 5 percent1 in the Corn Belt compared with 20 percent for first-generation Bt hybrids – adds one more reason for growers to consider choosing Dow AgroSciences SmartStax as they make their 2011 seed selections. "I would definitely recommend SmartStax to other growers. The reduced refuge is a big deal, and increased yield, along with not having to worry about rootworm pressure, is a big deal," Larson says.

Dow AgroSciences is offering SmartStax hybrids through Mycogen Seeds, Brodbeck Seeds, Dairyland Seed, Hyland Seeds, Pfister Seeds, Renze Seeds and Triumph Seed.