Effect of Reducing Plant Population on Yield and Kernel Characteristics of Sugary-2 and Normal Maize1
- P. S. Baenziger and
- D. V. Glover2
The maize (Zea mays L.) endosperm mutant sugary-2 (su2) has been proposed to modify the soft endosperm of opaque-2 (o2) maize to a harder, more vitreous texture, but su2 o2 has smaller, lighter kernels and often yields less than o2. Sugary-2 also yields less than normal maize. Little information is available concerning how su2 responds to different plant population densities or to competition during its vegetative or reproductive growth. This research studied the effect of reducing plant population by thinning at different times on yield, ear, and kernel characteristics of su2 and normal maize in the single cross maize hybrid Oh43 su2 × B37 su2 and its normal counterpart. The genotypes were planted at 74,775 plants/ ha and thinned to medium (49,850 plants/ha) and low (24,925 plants/ha) populations at seedling emergence, 30 days after emergence (DAE), 50 DAE, ad l0 days after midsilk (DAMS) and 20 DAMS.
Sugary-2 had significantly less grain weight per ear, plot yield, kernels per ear, kernel volume and kernel weight, and significantly higher kernel density than the normal counterpart. The genotypes × plant population treatment interaction was nonsignificant indicating both genotypes responded similarly to the reduced plant population treatments. The higher populations had lower grain weight per ear, greater plot yields, and fewer kernels per ear than did the low populations. Reducing population density after pollination had a greater affect on yield and ear characteristics than reducing population density before pollination. Kernel density was unaffected by the reduced plant population treatments. The low 20 DAMS treatment had the largest kernel weight and volume. For this treatment su2 had smaller kernels weights and volumes than did normal. The lower plot yields of su2 were caused by fewer kernels per ear and lower kernel weight than normal.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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