Soybean Tolerance to Flooding by Variety & Stage of Growth

G. Stevens, M. Rhine,

G. Shannon and D. Sleper

Univ. of Mo-Delta Center

Soybean varieties after flooding

Three flood tolerance tests

Test 1- Screened soybean germplasm/cultivars Test 2- Tolerance by growth stage (Group IV) Test 3- Tolerance by flood duration (Group IV)

Investigators: G. Shannon, G. Stevens, M. Rhine, B. Wiebold

Hand planted in hills

Plots flood 2 wks, rated, flooded 2 wks, rated

Most tolerant in 2002/2003

Group IV Group V

Hornbeck HBK R4920 Armor 52-C2

MFA Morsoy RT 4809 Armor 53-K3

NK S49-Q9 Delta King 5668 RR

P94B13 Golden Harvest H5492

P94B73 MFA RT5442 N

Southern Cross Titus Vigoro V 562 N RR

Stine 4202

53.3

32.4

51.6

12.0

50.5

19.8

0

10

20

30

40

50

60

Yie

ld, B

u/A

Average yield of the most tolerant, least tolerant and 30 varieties averaged over three maturity groups under flooded & non-flooded.

Most Tolerant Least Tolerant Mean–30 Var.

NF

NF

NF

F F F

39% less

77% less

61% less

Shannon, Stevens, and Wiebold 2003

Growth Stage/Flood Duration

Matthew RhineP94B73, Manokin, DKB 4868, Mersch-Denver, Delsoy 4710

Visual symptoms

Four test years

Reelfoot silt loam 2003 Reelfoot silt loam 2003 Sharkey clay 2003 Sharkey clay 2004

Similar results

Wet midseason

30

35

40

45

50

55

60

0 48 96 144 192

Flood Duration, hrs

Flooded at Bloom Growth StageY

ield

, b

u a

cre-1

Loam 2003, 2004,Clay 2003

DeltaKing 4868

Pioneer 94B73ManokinMersch-DenverDelsoy 4710

Averaged across environments

Flood Duration (Dur)

Soybean variety Flood response

DeltaKing 4868 Bu= 51.3 + 0.28 Hr –0.0023 Hr2 R2=0.97Plateau 144 hr

Pioneer P94B73 Bu= 47.9 + 0.14 Hr –0.0012 Hr2 R2=0.91Plateau 144 hr

Manokin Bu= 52.3 - 0.06 Hr R2=0.80

Mersch-Denver Bu= 45.3 + 0.05 Hr –0.0008 Hr2 R2=0.93Plateau 144 hr

Delsoy 4710 Bu= 39.2 + 0.10 Hr –0.0009 Hr2 R2=0.78Plateau 144 hr

Loam 2003, 2004,Clay 2003

Roots in Flooded Soil

Coffeeweed Sesbania exaltata

Soybean

2004 Clay Bloom Stage

0

5

10

15

20

25

30

35

40

0 48 96 144 192

Flood Duration, hrs

Yie

ld,

bu

acr

e-1

DeltaKing 4868Pioneer 94B73

Manokin

Mersch-Denver

Delsoy 4710

Flood Duration (Dur)

Soybean variety Flood response

DeltaKing 4868 Bu= 36.4 - 0.35 Hr +0.0012 Hr2 R2=0.93

Pioneer P94B73 Bu= 19.7 - 0.14 Hr +0.0004 Hr2 R2=0.98

Manokin Bu= 36.6 - 0.47 Hr +0.0017 Hr2 R2=0.92

Mersch-Denver Bu= 21.2 - 0.24 Hr +0.0009 Hr2 R2=0.90

Delsoy 4710 Bu= 34.9 - 0.43 Hr +0.0016 Hr2 R2=0.96

Clay 2004

Growth Stage Interactions

Effect Probability>F

Growth stage 0.007

Variety X G stage 0.002

Year X Soil X Var X G stage 0.085

Growth Stage Flooded 192 hours

Variety Growth stage Loam &Clay 03

Delsoy 4710 Check 38 bLeast tolerant V5 50 a

Bloom 33 b

R5 30 b

DeltaKing 4868 Check 47 aMost tolerant V5 44 ab

Bloom 51 a

R5 35 b

Lowest

Lowest

HurtHurt

Not hurt

Yields followed by same letter were not significant at 0.05 level.

Growth Stage Flooded 192 hours

Variety Growth stage Clay 04

Delsoy 4710 Check 36 aLeast tolerant V5 16 b

Bloom 11 b

R5 30 ab

DeltaKing 4868 Check 38 aMost tolerant V5 19 b

Bloom 18 b

R5 47 a

Lowest

Lowest

Not hurtNot hurt

Not hurt

Discussion

•Least tolerant varieties yield decline at 48 hrs.

•Tolerant varieties withstood 96 hrs flooding.

•Most injury to flooding was usually late season.

•Root morphology may be key to tolerance.

Bottom Line

• Soybean genetics- Use most tolerant germplasm in crosses, select individual plants with desired root morphology, consider moving root genes from coffeeweed into soybean.

•Irrigation management- Get soil profile watered up before going into late reproductive stages