SENESCENCE IN SWEET CORN AS INFLUENCED BY PHOSPHORUS-NUTRITION

Nutrient availability can affect the onset of senescence. Phosphate-ph osphorus (P) was added at the recommended and five times the recommend ed level to a Bernow fine-loamy, siliceous, thermic Glossic Paleudalf soil at Lane, OK. Senescence in stalk and shank internodes and cobs wa s rated in shrunken-2 sweet corn (Zea mays L.) cultivars at various de velopmental stages. Plant dry weight was determined at fresh market ha rvest. Stalk internode senescence rating increased through harvest. Th e internode subtending the ear node was almost completely senescent at anthesis. There were statistical, but likely not biologically importa nt, differences in stalk internode senescence between cultivars. Incre ased P occasionally increased stalk internode senescence rating and re duced plant dry weight. Increased P either decreased, or had no effect on, shank internode or cob senescence.