Planting date and moisture level effects associated with a leafy and a normal maize hybrid /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1990.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | Yield potential must be determined within a diversity of production environments to evaluate a maize (Zea mays L.) genotype. A leafy (914Lfy x 957Lfy) and a normal (Funks G4507) maize hybrid were evaluated over a series of planting dates and moisture levels. A significant hybrid x planting date interaction indicated grain yield was 6.1, 17.4, and 35.4% greater for the normal hybrid than for the leafy hybrid across the early, medium, and late planting dates, respectively. An interaction with year was also detected for both planting date and hybrid. Reduced yields were attributed to increased plant barrenness and decreased kernels ear^-1 and kernel weight. Plant height, total leaf number, and leaf area index (LAI) were significantly increased in response to the late planting date and to the leafy hybrid. Increased plant height associated with delayed planting was attributed to both greater node number and longer mean internode length. The LAI was 27% greater for the leafy hybrid than for the normal hybrid and approximately 20% greater for the medium and late plantings than for the early planting date. Total aboveground phytomass increased in the leafy hybrid across all planting dates at 50% silking; however, these differences were not detected at physiological maturity. In both hybrids, carbon dioxide exchange rates (CER) declined as planting was delayed; this decline was most severe for the late planting. The decline in CER was more rapid in the leafy hybrid than in the normal hybrid. The rate of kernel dry matter accumulation did not differ due to hybrid or planting date. The duration of grain filling was less for the leafy hybrid than for the normal hybrid. In both hybrids, delayed plantings reduced duration of grain fill. Stem dry matter accumulation and level of nonstructural carbohydrates were not affected by hybrid or planting date. This study failed to demonstrate an advantage of the leafy genotype over the normal genotype. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Agronomy." |
| Physical Description: | x, 104 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |