Variety selection is one of the most important decisions a cotton producer makes each season. The main thing most growers look for in a variety is consistent yield, followed closely by the genetic traits it possesses and fiber quality.
Deltapine 555 BG/RR has been the standard variety throughout the Southeast for consistent high yields and quality for a number of years. Last year, Florida growers planted more than 85 percent of their acreage to DP 555.
However, the registration for DP 555 and other single-gene Bt Bollgard varieties will expire on Sept. 30 of this year. This means seed will not be commercially available after this date, but if they are purchased by Sept. 30, they may be planted in 2010.
From an insect management standpoint, the transition from the single-gene Bollgard technology to two-gene Bt cotton technologies will bring improved control. Two-gene Bt cotton varieties currently available include Bollgard II and WideStrike. Both Bollgard II and WideStrike are superior to Bollgard for control of bollworms and other caterpillar pests such as armyworms and loopers.
However, the potential for worm damage still exists and both technologies should be scouted and treated on an as needed basis.
In 2009, there may be as many as nine different technology systems available for the Southeast: Roundup Ready Flex, Bollgard/Roundup Ready, Bollgard II/Roundup Ready, Bollgard II/Roundup Ready Flex, Widestrike, Widestrike/Roundup Ready, Widestrike/Roundup Ready Flex, Liberty Link and Bollgard II/Liberty Link.
Many changes have happened in the cottonseed industry over the past couple of years. In 2007, Monsanto bought Delta & Pine Land Company and divested itself of its Stoneville and NexGen brands. Bayer CropScience purchased Stoneville and Americot bought NexGen, in addition to other specific D&PL germplasm. Syngenta acquired 43 D&PL lines with Syngenta’s VipCot insect-resistant trait, but they have not yet been marketed.
The major players in the Southeast cottonseed market are Monsanto (Deltapine), Bayer CropScience (FiberMax and Stoneville), and Dow AgroSciences (Phytogen).
This year, Monsanto is introducing a new naming system for Deltapine varieties. Each variety will have four numbers in the name. The first two numbers indicate the year the variety is introduced and the second two numbers indicate relative maturity based on the following scale: 10-19=early, 20-29=early-mid, 30-39=mid, 40-49=mid-full and 50-59=full.
The first two varieties released for this year are DP 0924 B2RF and DP 0935 B2RF. DP 0924 B2RF is an early to mid-maturity, semi-smooth leaf variety with medium plant height and consistent high yield potential. It is very well adapted to the upper Mid-South and upper Southeast growing regions.
DP 0935 B2RF is a mid-maturity, smooth leaf variety with consistent high yield potential. It performs well across a wide range of soils and management techniques. It has the nectariless trait for plant bug suppression and has good overall fiber quality. Gin turnout is listed at 39.3 percent. (For more information visit www.deltapine.com.
Bayer CropScience says it expects to receive EPA approval for its new GlyTol glyphosate-resistant trait in 2009. Plants with the trait are resistant to glyphosate, but use a different gene and promoter than other company’s traits. The GlyTol trait is said to provide a high level of herbicide tolerance and crop safety to full-label rates of a number of different formulations of glyphosate herbicide over a wide application window.
The GlyTol-containing varieties will be available on a limited basis in 2009 with the focus on FiberMax varieties in the Southwest.
The following Stoneville varieties were released last year: ST 4498B2RF — an early-mid maturity, hairy leaf variety with medium plant height that provides excellent yield potential and fiber quality characteristics; ST 5458B2RF — a mid maturity, hairy leaf variety with medium plant height that produces yield and fiber quality packages similar to ST 4554B2RF, but matures about one week later.