1. Precision Planting of Corn (Zea mays L.) to Manipulate Leaf Geometry Guilherme Torres Department of Plant and Soil Sciences Oklahoma State University

2. 60% of yield improvement due to genetic advances and 40% due to management practices (Duvick, 1992; Cardwell, 1982) Corn Grain and Silage Yield Increase

3. Potential Benefits of Seed Orientation Spatial and temporal emergence Homogenous crop stands Rapid canopy closure o Moisture o Integrated weed management Light interception

4. Rationale Light can be the limiting factor in crop production (Stinson and Moss, 1960). Systematic leaf arrangement provide means for maximize light interception (Peters, 1961). Leaf architecture can optimize light interception and increase yield (Stewart et al., 2003) Leaf geometry and its effects offers potential strategies for improving production efficiency (Donald, 1963).

5. Dry Matter response to percent of intercepted solar radiation (Shibles and Weber, 1965)

6. Research Questions Can corn leaf orientation be manipulated by controlling seed position at planting? Which seed position can result in across-row leaf orientation and what is the effect on emergence? What is the effect of leaf orientation on light interception and grain yield ?

7. Greenhouse Experiment Description (c) Adrian Koller 8 treatments 5 Dekalb hybrids 400 seeds

8. Greenhouse Experiment Materials and Methods 10 seeds per treatment Medium flats Planted 2.5 cm deep Emergence Leaf angle at V4 o 0 ° to 30 ° (with-row) o 60 ° to 90 ° (across-row ) Analysis of variance Frequency distribution

9. Greenhouse Results

10. Leaf Angle and Emergence

11. Field Trial

12. 3 Seed Orientations o Upright, caryopsis pointed down, parallel to the row o Laying flat, embryo up, caryopsis pointed perpendicular to the row o Random 2 Corn Hybrids o Plagiophile- P0902HR o Erectophile- P1173HR o (within incomplete factorial arrangement) 3 Plant Populations Field Trial - Materials and Methods RCBD Row spacing: 76 cm Light interception Grain yield Row orientation UprightFlat

13. Field Results

14. Light Interception V10 growth stage

15. Light Interception R1 growth stage

16. Grain Yield

17. Conclusions Placement and arrangement of corn seed can influence rate of emergence and leaf orientation. Differences in light interception between treatments decreased with maturity. Effect of seed orientation on light interception was independent of plant population and hybrid. Yield (over sites, plant pop. and hybrids); ◦ Upright, 10% higher than Random ◦ Flat, 14% higher than Random

18. Thank You guilherme.torres@okstate.e du