Response of corn grain yield to spatial and temporal variability in emergence
2004
Liu, W. | Tollenaar, M. | Stewart, G. | Deen, W.
Potential yield benefits from improving within-row plant spacing variability and plant emergence variability in corn (Zea mays L.) production are often questioned by growers. Research was conducted at two locations in south-central Ontario during a 2-yr period to quantify the effects and interactions of plant spacing variability and plant emergence variability on growth and grain yield of corn. Nine treatments were established by hand planting corn rows with repeating six-plant sequences consisting of uniform and nonuniform spacing, even and uneven emergence, and their combinations. Spacing treatments consisted of (i) uniform within-row plant spacing of 20 cm; (ii) one 40-cm gap associated with a double; and (iii) one 60-cm gap associated with a triple in each six-plant sequence. Emergence treatments included uniform early emergence, a two-leaf stage delay, and a four-leaf stage delay for one plant in each six-plant sequence. Only plant emergence variability significantly affected plant height, leaf area index (LAI), dry matter accumulation, and grain yield. Compared with the uniformly early emerged plants, one out of six plants with a two-leaf stage delay in emergence reduced yield by 4%, and one out of six plants with a four-leaf stage delay reduced yield by 8%. Whereas corn plants next to a gap demonstrated compensatory growth, plants adjacent to a late emerging corn plant did not exhibit compensatory growth. These results indicate that corn is more responsive to plant emergence variability than plant spacing variability. Variation in plant emergence reduced yield, whereas variation in within-row spacing did not affect yield, and interactions between the two factors were not significant.
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