1. Impact of Rotation and Fumigation on 2006 Cotton Production in Reniform Infested Cotton Fields. Gazaway, W.S., K. Lawrence, and J.R. Akridge Auburn University

2. Test Field Placed in a cotton field with high reniform populations, located near Huxford, AL. Infested with reniform nematodes since mid 1980’s. Sustained substantial yield losses to reniform nematodes over last 20 years.

3. Objective of Study Evaluate: Non-host crops’ effect on cotton yield and on reniform populations. Compare 1- and 2-year rotations. If nematicide applied to cotton following rotation will further improve yield?

4. Crops Cotton- DPL449 BG/RR Corn- Pioneer 33M53RR Soybean- DPL 5634RR Peanut- AP 3

5. Nematicide Telone II- applied to ½ the cotton plots. Injected 3 gal/acre 18 in. deep into raised seed beds 3 weeks prior to planting.

6. Rotation Study Design 4 rows wide X 40 ft long. 32 treatments. 4 replications. Designed so 1- and 2- year cotton yields could be compared the same year. Randomized split plot.

7. 128 Plots- covers approximately 5 acres

8. Treatments evaluated in 2006 Yield data from Telone treated and untreated cotton plots following 1-year rotation with soybean, corn, peanut and continuous cotton. Total= 20 plots. Nematode population data from 2 year non-host rotation plots plus 2006 cotton plots. Total= 32 plots.

9. 20052006 plotsyieldnematodes peanut 4noyes corn 4noyes soybean 4noyes peanutcotton4yes corncotton4yes soybeancotton4yes cotton-N 4yes cotton 4yes Data Evaluated in 2006

10. 2006 Results

11. Pooled Data for Nematicide Reniform/100ccCotton 2006 Yield/Acre 4/1311/13 Telone73623441799 LB Untreated76734551540 LB LSD (0.05)353803112 LB Prob (F)0.86.009.0013

12. Pooled Data for Crops 2005 CropReniform/100ccCotton(2006) (LB/Acre) 4/1311/13 peanut25723211753 LB corn75325921734 LB soybean85632351522 LB cotton114034501550 LB LSD (.05)4991135158 LB Prob (F).0115.1620.0086

14. No Crop x Nematicide Interaction-2006 2005 crop4/1311/13Cotton yield Cotton (N) 119428871733 LB Cotton 108640131366 LB Corn (N) 70820321766 LB Corn 79831521702 LB Peanut (N) 32220281838 LB Peanut 19226151668 LB Soybean (N) 72124311619 LB Soybean 99140401424 LB LSD(.05)7051605223 LB Prob (F).0820.830.28

17. Peanut vs Cotton (+)(-) Nematicide Impact on Reniform Populations

18. 2 years versus 1 year non-host crops impact on reniform populations

20. Conclusion Addition of nematicide to cotton following 1 year of peanut and corn did not improve yield. Nematicide did improve cotton yield following soybean or cotton. One year rotation with corn and peanut as effective in improving cotton yield as Telone treatment.

21. Conclusion Reniform populations rebound to damaging levels in 1 year back in cotton. Reniform populations higher in plots with 2 years cotton (2005 & 2006) than in plots with just one year in cotton (2006). Two years of corn or peanut had lower reniform populations than 1 year corn or peanut ( e.g.cotton in 2005; corn or peanut in 2006).