Do delay tactics affect silking date and yield of maize inbreds? Stephen Zimmerman Creative Component November 2015

Transcription

1 Do delay tactics affect silking date and yield of maize inbreds? Stephen Zimmerman Creative Component November 2015

2 Overview Acknowledgements My Background Introduction Materials and Methods Results and Discussion Conclusion Questions

3 Acknowledgements Major Professor Dr. Allen Knapp Program of Study Committee Dr. Thomas Loynachan and Dr. Kenneth Moore Program Coordinator Dawn Miller Mentors/Supporters Patrick McMullan, Adda Sayers, Darrin Roberts, and John Schmidt DuPont Pioneer Production Research staff

4 My Background Grew up near Harlan, IA on a family farm. Currently, my wife Beth and I live in Ankeny, IA. Enjoy, the outdoors, gardening, visiting family, and attending ISU sporting events.

5 Career DuPont Pioneer Production Research Group KMR Carroll, IA Independent research company that conducts yield trials across the Midwest. ISU Bachelors of Science in Agronomy Bizy Farms Inc Corn/soybean farm with swine confinements. Iowa Western Community College AAS Ag Business degree

6 Production Research Production of hybrid corn requires a female parent to be pollinated by a male parent. Production Research conducts research on parents going into production. Research projects focus on practices that influence seed quality, yield, and reliability.

7 Introduction To facilitate a proper nick standard practice is to delay the male by planting at a later date or by mechanical means after emergence. Because of weather or other unforeseen issues, planting the male at the recommended delay is not possible. The results in a poor nick, which can result in reduced yield, and increased outcrossing due to a low pollen environment. Currently, even if the agronomist realizes this is going to occur, few corrective actions are available.

8 The Nick Ideal Situation Desired. planting timing with 200 GDU delay Female 1400 GDUs Male 1200 GDUs Problem Rain causes male to be planted at 300 GDU delay. Female 1400 GDUs Male 1200 GDUs

9 Materials and Methods Trial conducted in 2013 & 2014 Locations in 2013 Alleman, IA; Windfall, IN; Champaign, IL; York, NE Locations in 2014 Alleman, IA; Windfall, IN; Champaign, IL; Constantine, MI Split plot design with 4 replications Whole plot: Entry SP: Treatment Plot represented by four rows of female parent with one row of mixed male pollinator on each side. Data collected on center two female rows. M F F F F M Plot length FT. 4 rows wide or 10 FT.

10 Materials and Methods Entries whole plot Entry No. GDUs to silk Plant Height (inches) Treatments split plot Treatment No. Treatment Timing Comments 1 Untreated check UNT 2 Cut at V2 V2 Leave 1 inch of stalk above soil 3 Cut at V5 V5 Standard cut leave 4 in. stalk 4 Vertical Cut at V5 V5 Cut plant vertically leaving stalk intact

11 V2 Cut Treatment

12 V5 Cut Treatment

13 V5 Vertical Cut Treatment

14 Data Collected Early Stand count not presented Late stand count not presented GDUs calculated from % silking dates Growing Degree Unit = (Tmax +Tmin)/2 Tbase (50 degree F min) Barren count not presented Yield 80k units/female acre (Weight, moisture, kernels/pound, saleable seed %) Small discard Large discard not presented Percent cold germination Warm germination not presented

15 Analysis Completed using PROC GLIMMIX in SAS EG version 6.1 Entry and treatment run as fixed factors Factors considered significant at alpha level 0.05 Least square means calculated using a LSMEANS statement direct comparisons made with an ESTIMATE statement

16 Results Cut effect on silking Treatment effects on GDUSLK (growing degree units to 50% silking) delay compared to untreated check GDUs of Delay From UTC A 33 B 0 C 2.V2_CUT 3.V5_CUT 4.V5_VC LS means with the same letter are not significantly different (P<=0.05) Type III tests of fixed effects GDUSLK (growing degree units to 50% silking) Effect Num DF Den DF F Value Pr > F Entry <.0001 Treatment <.0001 EntryTreatment

17 Results GDU s to silking GDUs ,503 1, ,515 1, ,545 1, Entry 1 Entry 2 Entry 3 Entry 4 1,492 1, UNT 2.V2_CUT 3.V5_CUT 4.V5_VC

18 Results Entry Treatment Contrasts for the V2 cut delay, Entry 4 compared to Entries 1, 2 and 3. Treatment Entry Treatment Entry Estimate Standard DF t Value Pr > t (GDU) Error 2.V2_CUT 1 2.V2_CUT V2_CUT 2 2.V2_CUT V2_CUT 3 2.V2_CUT

19 Results Silking Duration Silking duration (GDUs) A 67.3 B 64.2 B 62.5 B 0 2.V2_CUT 1.UNT 3.V5_CUT 4.V5_VC LS means with the same letter are not significantly different (P<=0.05).

20 Results Small discard A 9.3 A 9.0 A % small discard B UNT 4.V5_VC 3.V5_CUT 2.V2_CUT LS means with the same letter are not significantly different (P<=0.05).

21 Results Saleable seed A 91.0 % Saleable seed B 90.0 BC 89.4 C V2_CUT 3.V5_CUT 4.V5_VC 1.UNT LS means with the same letter are not significantly different (P<=0.05). Type 3 Tests of Fixed Effects % Saleable Seed Effect Num DF Den DF F Value Pr > F Entry <.0001 Treatment EntryTreatment

22 Results Saleable seed % saleable seed UNT 2.V2_CUT 3.V5_CUT 4.V5_VC Entry 1 Entry 2 Entry 3 Entry 4 An asterisk indicates a sign. diff. (P<=0.05) with the untreated check within an entry.

23 Results 80K units % dif. from UNT V2_CUT 3.V5_CUT 4.V5_VC An asterisk indicates a sign. diff. (P<=0.05) compared to the UNT.

24 Results Cold germination Percent cold germination shown entry by treatment. % Cold germination UNT 2.V2_CUT 3.V5_CUT 4.V5_VC 70 Entry 1 Entry 2 Entry 3 Entry 4

25 Conclusion V2 Cut treatment most effective at delaying female silking (43 GDUs). V2 effect on seed yield minimal ( 3.5% 80k units/acre). V2 cut did not cause loss of female plant population. V2 cut did not negatively effect warm/cold germination. V2 cut slightly decreased small discard and increased salable seed percentage.

26 Questions? Thank you!

27 Silk timing and delay Type III Tests of Fixed Effects GDUSLK Effect Num DF Den DF F Value Pr > F EntryNUM <.0001 TRT <.0001 EntryNUMTRT Estimates Label Estimate Standard DF t Value Pr > t Error GDUs to 50% silk C 1508 A 1498 B 1465 C 1.UNT vs 2.V2_CUT < UNT vs 3.V5Cut < UNT vs 4.V5_VC TRT Least Squares Means 1560 TRT Estimate Standard DF Dif. in 1540 Error GDUs 1,504 from ,503 UNT 1.UNT V2_CUT V5_CUT V5_VC , ,450 GDUs to 50% silk/ UNT 2.V2_CUT 3.V5_CUT 4.V5_VC 1,515 1,505 1,466 1,461 1,545 1,530 1,492 1,490 1,492 1,487 1,465 1,468 1.UNT 2.V2_CUT 3.V5_CUT 4.V5_VC 1400 Entry 1 Entry 2 Entry 3 Entry 4 Asterisk indicates sig. dif. from UNT at.05 level

28 80k/acre Female yield Type III Tests of Fixed Effects 80K/acre yield Effect Num Den DF F Value Pr > F DF EntryNUM TRT <.0001 EntryNUMTRT Estimates Label Standard DF t Value Pr > t Error 1.UNT vs 2.V2_CUT % yield change from UNT V2_CUT 3.V5_CUT 4.V5_VC 1.UNT vs 3.V5Cut UNT vs 4.V5_VC

29 Duration of silking Type 3 Tests of Fixed Effects Effect Num DF Den DF F Value Pr > F EntryNUM A TRT <.0001 EntryNUMTRT Estimates Label Estimate STD ERR DF Pr > F 1.UNT vs 2.V2_CUT UNT vs 3.V5Cut Length of silking (GDUs) B 64.2 B 62.5 B 1.UNT vs 4.V5_VC V2_CUT 1.UNT 3.V5_CUT 4.V5_VC GDUs UNT 2.V2_CUT 3.V5_CUT 4.V5_VC slk 50slk 90slk

30 Percent Saleable Seed Type 3 Tests of Fixed Effects Effect Num DF Den DF F Value Pr > F EntryNUM <.0001 TRT EntryNUMT RT Contrasts Label Estimate STD ERR DF Pr > F 1.UNT vs 2.V2_CUT 1.UNT vs 3.V5Cut 1.UNT vs 4.V5_VC < Effect TRT Estimate Diff. from UNT TRT 1.UNT TRT 2.V2_CUT TRT 3.V5_CUT TRT 4.V5_VC % saleable seed % saleable seed A 90 B 90 BC 89 C 2.V2_CUT 3.V5_CUT 4.V5_VC 1.UNT UNT 2.V2_CUT 3.V5_CUT 4.V5_VC Entry 3 4 Asterisk indicates sig. dif. from UNT at.05 level

31 Small discard Type 3 Tests of Fixed Effects Effect Num DF Den DF F Value Pr > F EntryNUM <.0001 TRT EntryNUMTRT Estimates Label Estimate STD ERR DF Pr > F 1.UNT vs 2.V2_CUT < UNT vs V5Cut 1.UNT vs 4.V5_VC % Small Discard A 9.3 A 9.0 A 7.9 B 1.UNT 4.V5_VC 3.V5_CUT 2.V2_CUT Effect TRT Estimate Diff. from UNT TRT 1.UNT TRT 2.V2_CUT TRT 3.V5_CUT TRT 4.V5_VC % Small Discard UNT 2.V2_CUT 3.V5_CUT 4.V5_VC 0 Entry 1 Entry 2 Entry 3 Entry 4 Asterisk indicates sig. dif. from UNT at.05 level

32 Large discard Type 3 Tests of Fixed Effects Effect Num DF Den DF F Value Pr > F EntryNUM <.0001 TRT EntryNUMTRT Contrasts Label Num DF Den DF F Value Pr > F 1.UNT vs 2.V2_CUT UNT vs 3.V5Cut UNT vs 4.V5_VC % Large discard UNT 2.V2_CUT 3.V5_CUT 4.V5_VC Entry 3 4

33 Kernels per pound Type 3 Tests of Fixed Effects Effect Num DF Den DF F Value Pr > F EntryNUM <.0001 TRT EntryNUMTRT Contrasts Label Num DF Den DF F Value Pr > F 1.UNT vs V2_CUT 1.UNT vs V5Cut 1.UNT vs 4.V5_VC Kernels/lb Entry UNT 2.V2_CUT 3.V5_CUT 4.V5_VC

34 Harvest stalk count Type 3 Tests of Fixed Effects Effect Num Den DF F Value Pr > F DF EntryNUM TRT EntryNUMTRT Contrasts Label Num DF Den DF F Value Pr > F 1.UNT vs V2_CUT 1.UNT vs V5Cut 1.UNT vs 4.V5_VC Harvest stalk count UNT 2.V2_CUT 3.V5_CUT 4.V5_VC Entry 3 4 One plant in row equal 500 plants per acre

35 Process of analysis Data checked for outliers and bad data points Performed Bartlett test to confirm normalized data Proc mixed determined if location or year were significant factors PROC GLIMMIX used to determine fixed effects, LSMEANS and significant differences Estimate statement made direct comparisons of treatment effects.

36 SAS Code proc glimmix plots=residualpanel; class entrynum trt rep loc; model kersalpct = entrynum trt/ ddfm=kr; random rep(loc) entrynumrep(loc) loc; lsmeans entrynum /lines; estimate '1.UNT vs 2.V2_CUT' trt 1 100/cl; estimate '1.UNT vs 3.V5Cut' trt 1 010/cl; estimate '1.UNT vs 4.V5_VC' trt 1 001/cl; run; PROC MIXED METHOD=REML; CLASS entrynum Loc TRT Rep; MODEL warm=entrynum Loc TRT entrynumloc entrynumtrt LocTRT entrynumloctrt/ddfm=kenwardroger; RANDOM Rep(Loc) entrynumrep(loc) / TYPE=VC;; LSMEANS entrynum Loc TRT entrynumloc entrynumtrt LocTRT entrynumloctrt / ; RUN; QUIT;