Choosing the variety best suited for your Mid-South farming operation is still the number one decision in maximizing cotton profits. Yields are important but profitability remains the most important issue. Technology considerations of Bollgard®, Roundup Ready® and BXN® must be carefully analyzed in order to add to bottom line profits.

Criteria that should be considered include:

Short Season Varieties.
New short-season varieties like DP 5111, DP 425 RR and DP 436 RR are ideally suited for the Mid-South. These varieties excel in early seeding growth and vigor and handle the cool soil planting conditions better than some mid-season varieties.

This extra growth and vigor offers dual benefits in helping push the plant through the danger zone of the seedling disease complex, and provide producers with a more uniform stand for over-the-top applications of Roundup Ultra on Roundup Ready varieties and other post emergence work.

The variety trait of early season vigor in these new varieties is especially important in no till and conservation tillage.

Roundup Ready.
The use of the Roundup Ready Systems, featured at one of the cotton stops at the Milan No Field Day, offers reduction in weed control cost while providing seed beds free of residual herbicide.

Pre-plant herbicides, especially during wet, cool springs, may stunt cotton in the early stages of growth and delay maturity. Some of our plot cooperators are reporting extra costs associated with the BXN weed control system. Some growers are having to use pre-plant herbicides and still come back with additional over-the top applications to clean up Buctril® escapes, especially
during this year's droughty conditions. These late applications may affect labeled plant-back restrictions next spring.

REPLICATED IN SEASON PLANT MAPPING DATA
DELTAPINE SEED AGRONOMIC SERVICE 1997
JERRY WHITE FARM, HUNTINGTON, TENNESSEE

Plant Mapping.
Our plant mapping data supports early fruit initiation on widely adapted early varieties as compared to other varieties planted in the area.

PRELIMINARY VARIETY TRIALS**
UNIVERSITY OF TENNESSEE

*Check varieties
** Data taken from preliminary variety trial data 1997 table 11 PVT-1 University of Tennessee

Early Fruiting Advantage.
Cotton varieties that have the ability to fruit early, beginning on the 5th to 6th node versus varieties initiating fruit on the 7th to 9th node, could have a week head start, translating to an early harvest and higher first picking percentages. The early first position bolls on these early starting varieties are even more important in stressful and dry years like we are experiencing. Older, first position bolls are just safer bolls and are less likely to shed under drought stress.

Early boll load and retention is the main factor in the cotton plant's ability to manage plant height in aggressive growing conditions. The increased DD 60 accumulation, pushing earlier boll load coupled with excellent retention, has been very instrumental in plant height control and less need for PGR.

The new short season varieties are ideally suited for once-over picking, reducing harvest cost. High retention of first position bolls has a major impact on boll maturation. The traditional 55 to 65 days may be shortened when over 50 percent of the plant bolls are on 1st position.

Dr. Owen Gwathmey, Department of Plant and Soil Science of the University of Tennessee Agricultural Experiment Station of Jackson, Tennessee, in his 1997 Preliminary Cotton Test, reports the earliness of several varieties in conjunction with yield and percent open on the first picking.

Bollgard Varieties Influence Earliness:
Dr. Gary L. Lentz, Associate Professor, University of Tennessee's Department of Entomology and Plant Science in his 1997 Comparison of Yield and Maturity Test, reports higher yields and significantly more cotton at first harvest with new Bollgard varieties. This comparison was made with DP 20 B and DP 50 B compared with their recurrent parents.

DP 20 B produced the highest yields of 1,040 lbs. lint with 75.8 percent at first harvest. Worm control at below economic thresholds may be a factor in the increased yields. These new short season cotton varieties continue to demonstrate in cotton fields their earliness in 1998 with early fruit initiation and boll load.

Comparison of Yield and Maturity of Four Deltapine Cotton Varieties
Lint Yield (lb.)

By Jim Presley
Deltapine Seed Midsouth Regional Agronomic Service Manager

Bollgard®, Roundup Ready® and Roundup Ultra™ are trademarks of Monsanto.
BXN® is a registered trademark of Stoneville Pedigreed Seed.
Buctril® is a registered trademark of Rhone­Poulenc.

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