The Early Season Effect of Seed Treatment on Early Generation Maize Populations. Andrew Frey Creative Component April 18, 2014

Transcription

1 The Early Season Effect of Seed Treatment on Early Generation Maize Populations Andrew Frey Creative Component April 18,

2 Overview My Background Introduction Materials and Methods Results and Discussion Conclusions Acknowledgements 2

3 Background Raised in Northeast Iowa---Fayette Home of Upper Iowa University Crop and livestock farm Father and brother now operate 2500 acres of corn and soybeans Family- wife Betsie of 13 years Brayden 7 Kamryn 4 3

4 Career Graduated from Iowa State University in 1999 Major in Ag Systems Technology Minor in Agronomy 14 years in corn research 5 years with JC Robinson Seed Company (Golden Harvest) in Nevada, IA 9 years with Monsanto-Research Assistant/Associate 3+ years in High-oil corn breeding in Ames/Huxley, IA 5 ½ years in Independence, Iowa Play key role in company s global breeding process improvement initiatives Began MS in Agronomy in 2006! 4

5 5 Project Introduction Today s commercial corn breeding Increase genetic gain Decrease development time for new products to reach market 2008 Monsanto strategy- double corn yields by 2030 Presence of early season environmental stress Eliminates breeding lines before they have been phenotyped Seed treatments can possibly play a vital role in early season crop survival Photo courtesy of ISU extension

6 Introduction Seed treatment Value of treatment sector doubled between 2002 and 2008 to $2 bil, projected $3.5 bil by 2016 (Munkvold, 2009; Markets and Markets, 2012) Numerous factors have contributed Protect high investment in seed in presence of greater environmental stresses Operator safety Environmental concerns 6

7 Introduction (cont.) Evolution of seed treatment 60 AD wine and cypress leaves for protection against storage insects ISU Extension, Bayer, first chemical fungicide that didn t inhibit germination 1947 ICI, first insecticidal seed treatment 1970s-1980s systemic products that move up the plant and protect new growth Baylis, s neonicotinoid insecticides Today combinations of fungicides, insecticides, nematicides for above and below ground protection Future multi-product chemical and biological formulations for biotic and abiotic defense (Markets and Markets, 2012; Munkvold, 2009) 7

8 Introduction (cont.) Seed vigor the seed properties that determine the potential for rapid, uniform emergence and development of seedlings under a wide range of field conditions -AOSA defined Comparison of the characteristics of high and low vigor seed lots -----Vigor level----- High Low Mean rate of germination Fast Slow Synchrony of germination Good Poor Mean seedling size Large, uniform Small, variable Emergence potential Good in most Poor in less than soil conditions optimum soil Conditions Storage potential Good Poor 8 Adopted from Bennett, 2003

9 Introduction (cont.) Seed vigor result of: Seed quality derived from growing environment s effect on the mother plant Storage conditions Effect of inbreeding High quality standards necessary by seed companies 9

10 Introduction (cont.) Doubled haploid breeding Haploid induced kernels selected Double with colchicine generations to 100% homozygosity 2. Simpler nursery logistics 3. Higher reproducibility in early generation testing 4. Speeds up marker-assisted selection 10 Prasanna et al, 2012

11 Project Basis In 2010 Monsanto transitioned to 100% treating of early generation breeding populations Automation was developed to improve efficiency of the seed processing/treating This project is an opportunity to see whether true differences can be detected between treated and untreated lines Evaluate emergence and seedling vigor (SDV) scores + bonus flowering observations Compare DH vs conventional breeding type 11

12 Materials and Methods Experiment conducted in 2011 at 3 locations 4 active breeding populations RM DH and conventional breeding types Lines phenotyped for ear and grain characteristics, discarded undesirables Adequate seed retained for breeding and advancement needs 12

13 Materials and Methods 250 kernels from each line 40k for warm germination testing (ISU Seed Lab) 40k for cold germination testing (ISU Seed Lab) 90k treated with Monsanto standard inbred formulation 0.30 fl. oz/cwt Maxim-XL (Fludioxinil + Mefenoxam) fungicide Fludioxinil broad spectrum contact/protective activity Mefenoxam systemic activity against narrow spectrum of pathogens 0.25 mg a.i./kernel Poncho 600 (clothianidin) insecticide Systemic early season protection against above and below ground insects 13

14 Experimental Design Split plot of a randomized complete block design Main block was population (group) Split plot was treatment/no treatment Order of treatments randomized 2 planting dates/loc (early and late planned) Plot parameters planted row lengths 32,000-38,000 ppa planted density on 30 rows Mimics length used for phenotypic evaluation and selfpollinating requirements 14

15 Location Summary 3 locations in RM breeding and field testing zone All are home site nurseries at Monsanto corn breeding locations All pattern-tiled, uniform and highly productive sites for research 15 Corn Maturity map, Nu Tech Seed, LLC

16 16 Location Summary

17 Planting Sites encouraged to plant first rep as early as possible, second later in spring Normal target early planting for region is April Cooler than normal temperatures in April and early May resulted in planting delays Planting date effect removed from analysis, instead handled as 2 reps 17

18 18 Planting and Climate Summary

19 2011 Temperatures Source 19

20 Plot Layout Spencer layout 2 reps Each rep planted 8 rows wide 20

21 21 Data Collection Seedling vigor (SDV) Subjective rating collected at V2- V4 stage Prior to rapid internode elongation at V6 Lines scored above average 4-6 average 7-9 below average Must distinguish (G) from (GxE) differences Field variations Equipment failure or irregularities

22 Data Collection I collected data at each location Two round-trip traveling days in back to back weeks Location conditions Olivia very dry and crusted after brief heavy rains in days following planting Spencer received minor hail on the morning I arrived for data collection Emergence and SDV Final stand counts collected at same time as SDV scored Flowering data collected at Independence only 22

23 SDV Differences Strong vigor vs. poor vigor 23

24 24 Normal Distribution of SDV

25 Results Seedling vigor Location, Group, and Treatment all significant at 0.05 level SDV (all locations) SDV scores 6 6 SDV Score A 4.90 B LS Means SDV Score A 4.67 A 4.72 A 5.15 B LS Means Treated Untreated Treatment 3 Group 3 Group 1 Group 4 Group 2 Group Means followed by same letter are not different 25

26 Results Seedling vigor Contrast between DH (1&2)and segregating (3&4) did not show significance Future experiment-pedigrees generated as both DHs and segregating SDV SDV score Treated 4.83 Untreated 5.03 Treated 5.27 Untreated Treated Untreated Treated 4.81 Untreated SDV Group by Treatment

27 Results Emergence Group, treatment, and (location x treatment) effects all highly significant Emergence (all locations) Emergence by Group Emergence % A B LS Means Emergence % A B B C LS Means 0.8 Treated Treatment Untreated 0.7 Group 3 Group 4 Group 1 Group 2 Group Means followed by same letter are not different 27

28 Results Emergence-only Olivia significant Independence Olivia Spencer Emergence % A A LS Means Emergence % A B LS Means Emergence % A A LS Means Treatment Treatment Treatment Means followed by same letter are not different 28

29 Results Emergence differences Olivia-284 GDD during May Spencer-329 GDD during May Independence-338 GDD during May Greatest cold stress at Olivia + heavy rain and crusting after planting 29

30 Results Possible relationship between improved SDV and emergence but no correlation analyzed Contrast highly significant between breeding types (emergence) SDV scores Emergence by Group SDV Score A 4.67 A 4.72 A 5.15 B LS Means Emergence % A B B C LS Means Group 3 Group 1 Group 4 Group Group 3 Group 4 Group 1 Group 2 Group Group 30 Means followed by same letter are not different

31 Bonus Results Treatment effect on flowering date 31 Average number of days to 50% silk, 50% pollen shed

32 Conclusions Seed treatment had a positive effect on SDV at all locations in this study Olivia experienced the harshest conditions in 2011and showed the greatest seed treatment advantage 32

33 Conclusions Current breeding practices that support the use of seed treatment Increasing percentage of commercial maize breeding is doubled haploid Large investment needed to initiate populations Maximum population size needed Many fixed inbred lines that lack vigor may be grown in the field 33

34 Future Research in Seed Treatment A multi-year, multiple location study is warranted and this study should incorporate True early planting dates Same pedigrees as both DH and conventional Larger populations Future research conducted in this manner should confirm that the standard practice of applying seed treatment to early generation maize is beneficial 34

35 Acknowlegements Family Monsanto colleagues Judd Maxwell Kevin Betz Dr. Knapp Dr. Moore Dr. Lamkey Dawn Miller Jesse Drew Entire MS in Agronomy team 35

36 36 Questions?