Effect of One- and Two-Eared Selection on Stalk Strength and Other Characters in Maize
- S. Jampatonga,
- L.L. Darrah *b,
- G.F. Krausec and
- B.D. Barryd
- a National Corn and Sorghum Research Center, Kasetsart Univ., Klangdong, Pakchong, Nakhonratchasima 30320, Thailand
b USDA-ARS Plant Genetics Research Unit and Dep. Agronomy, Univ. of Missouri, 110 Curtis Hall, Columbia, MO 65211 USA
c Dep. Statistics, Univ. of Missouri, 105 Math Science Building, Columbia, MO 65211 USA
d USDA-ARS Plant Genetics Research Unit retired and Dep. Entomology, Univ. of Missouri, 204 Curtis Hall, Columbia, MO 65211 USA
Prolificacy associated with higher grain yield in maize (Zea mays L.) has been widely documented. However, one serious concern is that prolificacy appears associated with poor stalk strength and plant standability. The objective of this research was to compare stalk strength and other agronomic characters of one- and two-eared subpopulations derived from three maize populations (MoSQA(S7-H)C8 × Georgia Cow Corn [ACC]; MoSQB(S8-H)C8 × Georgia Cow Corn [BCC]; SI171). Entries were evaluated by using nine combinations of three levels of nitrogen (N) application (90, 180, and 270 kg ha−1 N) and three levels of plant density (35 800, 47 800, and 59 800 plants ha−1). Stalk crushing strength showed significant differences between one- and two-eared subpopulations for ACC and BCC, but it was not significant for SI171. One-eared subpopulations had higher rind penetrometer resistance than two-eared subpopulations for all populations. Two-eared selections generally resulted in poorer root and stalk strength. However, total grain yield of the two-eared subpopulations was significantly higher than that of the one-eared subpopulations for BCC and SI171, but not for ACC. Prolificacy has significant potential as a novel character for grain yield improvement in the future. Selection for prolificacy alone, representing indirect selection for grain yield, would produce undesirable effects on other agronomic characters, especially root and stalk strength. Concurrent improvement for total grain yield, prolificacy, and root and stalk strength by using a standardized, weighted selection index should be used to extract the real benefit of the prolific character.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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