Author
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Russo, Vincent |
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Submitted to: Cereal Research Communications
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/5/1995 Publication Date: N/A Citation: N/A Interpretive Summary: It is not clear whether senescence affects mineral content in plants or whether it is the reverse. This research was conducted to determine the relationship between senescence and mineral content and to provide insight into plant development and the aging process. Seed of several sweet corn cultivars were sown at planting dates from 2 April to 14 May 1993 at Lane, Okla. At fresh market harvest stalk internode tissues were rated for degree of senescence and analyzed for content of minerals (N, P, K, NO**2, NO**3, PO**4, SO**4, Ca, Fe, Mn, Mg, and Na). Only senescence rating and contents of N, P, K and Na were affected by planting date or internode or cultivar. As planting date was delayed, senescence rating and P content increased, while N and Na content decreased. The highest K content was in plants sown on 30 April. From internodes that were progressively higher on the stalk, senescence rating and P content increased, K and Na content decreased, but N content was not affected. Senescence rating patterns and content of minerals were different among the cultivars tested. At the developmental stage for fresh market harvest, mineral contents were not correlated with senescence ratings in internodes. Senescence in the pith tissues of sweet corn stalks does not appear to affect the transport of minerals. Technical Abstract: Tissues in internodes in sweet corn (Zea mays L.) at fresh market harvest exhibit various stages of senescence. This study was conducted to determine if internode senescence is an indicator of mineral content in internodes. On 2, 19, and 30 April and 14 May 1993, seeds of standard sugary (su), sugary enhancer (heterozygous, Sese; homozygous, sese), and shrunken2 (sh2) sweet corn cultivars were sown at Lane, Okla., in a Bernow fine-loamy (siliceous, thermic Glossic Paleudalf) soil. At fresh market harvest senescence rating and amounts of Kjeldahl nitrogen (N), nitrate-N (NO**3), nitrite-N (NO**2), Kjeldahl phosphorus (P), phosphate (PO**4), potassium (K), sulfate (SO**4), calcium (Ca), iron (Fe), manganese (Mn), magnesium (Mg) and sodium (Na) in internodes near the base of the stalk, subtending the ear, and between the ear node and the tassel were determined. Senescence ratings were higher as planting date was later and internodes were higher on the stalk. Senescence ratings were different for genotypes. About 0.3% of N was NO2 and NO3, and approximately 30% of P was PO**4). As planting date was later N and Na content decreased. Lowest P, and highest K, content was in plants sown on 30 April. Content of N was not changed, P increased, and those of K and Na decreased as internodes were higher on the stalk. Contents of N, P and K were significantly different for genotypes. Mineral contents were not significantly correlated with senescence ratings in internodes. |
