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Precision Planting of Corn ( Zea mays L.) to Manipulate Leaf Geometry. Guilherme Torres Department of Plant and Soil Sciences Oklahoma State University. Corn Grain and Silage Yield Increase . 60% of yield improvement due to genetic advances and 40% due to management practices
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Precision Planting of Corn (Zeamays L.) to Manipulate Leaf Geometry Guilherme Torres Department of Plant and Soil Sciences Oklahoma State University
Corn Grain and Silage Yield Increase • 60% of yield improvement due to genetic advances and 40% due to management practices • (Duvick, 1992; Cardwell, 1982)
Potential Benefits of Seed Orientation • Spatial and temporal emergence • Homogenous crop stands • Rapid canopy closure • Moisture • Integrated weed management • Light interception
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).
Dry Matter response to percent of intercepted solar radiation (Shibles and Weber, 1965)
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 ?
8 treatments 5 Dekalb hybrids 400 seeds Greenhouse Experiment Description (c) Adrian Koller
Greenhouse Experiment Materials and Methods • 10 seeds per treatment • Medium flats • Planted 2.5 cm deep • Emergence • Leaf angle at V4 • 0 ° to 30 ° (with-row) • 60 ° to 90 ° (across-row) • Analysis of variance • Frequency distribution
Field Trial - Materials and Methods • 3 Seed Orientations • Upright, caryopsis pointed down, parallel to the row • Laying flat, embryo up, caryopsis pointed perpendicular to the row • Random • 2 Corn Hybrids • Plagiophile- P0902HR • Erectophile- P1173HR • (within incomplete factorial arrangement) • 3 Plant Populations • RCBD • Row spacing: 76 cm • Light interception • Grain yield Flat Upright Flat Row orientation
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