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

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.

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?

Crops

• Cotton- DPL449 BG/RR

• Corn- Pioneer 33M53RR

• Soybean- DPL 5634RR

• Peanut- AP 3

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.

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.

128 Plots- covers approximately 5 acres

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.

2005 2006 plots yield nematodes

peanut peanut 4 no yes

corn corn 4 no yes

soybean soybean 4 no yes

peanut cotton 4 yes yes

corn cotton 4 yes yes

soybean cotton 4 yes yes

cotton-N cotton-N 4 yes yes

cotton cotton 4 yes yes

Data Evaluated in 2006

2006 Results

Pooled Data for Nematicide

Reniform/100cc Cotton 2006

Yield/Acre4/13 11/13

Telone 736 2344 1799 LB

Untreated 767 3455 1540 LBLSD (0.05) 353 803 112 LB

Prob (F) 0.86 .009 .0013

Pooled Data for Crops

2005 Crop Reniform/100cc Cotton(2006)

(LB/Acre)4/13 11/13

peanut 257 2321 1753 LB

corn 753 2592 1734 LB

soybean 856 3235 1522 LB

cotton 1140 3450 1550 LBLSD (.05) 499 1135 158 LB

Prob (F) .0115 .1620 .0086

1753 1734

15271550

1400

1500

1600

1700

1800

2006 Seed Cotton Yield (LB/A)

pnut corn sybn cot

No Crop x Nematicide Interaction-2006

2005 crop 4/13 11/13 Cotton yieldCotton (N) 1194 2887 1733 LBCotton 1086 4013 1366 LBCorn (N) 708 2032 1766 LBCorn 798 3152 1702 LBPeanut (N) 322 2028 1838 LBPeanut 192 2615 1668 LBSoybean (N) 721 2431 1619 LBSoybean 991 4040 1424 LBLSD(.05) 705 1605 223 LB

Prob (F) .082 0.83 0.28

1838

1766

1619

1733

1668

1702

1424

1366

0

500

1000

1500

2000

LB

/AC

RE

nematicide - nematicide

2006 Cotton Yield Following 2005 Crop

peanut corn soybean cotton

0

500

1000

1500

2000

2500

3000

fall 05 spr 06 fall 06

cont cot pnut 1 yr corn 1 yr sybn 1 yrReniform response to 1 yr cotton

0500

100015002000

25003000

fall 05 spr 06 fall 06

cot 05 pnut 05 corn 05 sybn 05

19172612

3131

4006

0

1000

2000

3000

4000

5000

Fall Populations-2006

pnut-cot(N) pnut-cot cot-cot(N) cot-cot

Peanut vs Cotton (+)(-) Nematicide Impact onReniform Populations

525

94

263

87

0

100

200

300

400

500

600n

ema/

100c

c

Fall Populations-2006

cot-corn corn-corn cot-pnut pnut-pnut

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

Reniform Populations following 2 year Crop Rotation

0

1000

2000

3000

4000

fall 05 spr 06 fall 06

Ren

ifo

rm/ 1

00cc

cot-cot pnut-pnut corn-corn sybn-sybn

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.

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).