Abstract
Nitrate-N and Cl⁻ concentrations were measured in the petioles of cotton plants at intervals during the 1972 and 1973 seasons at three irrigated locations across the Southern High Plains of Texas. Soils at the southern and central locations were thermic Alfisols (Brownfield Ifs and Amarillo sl, respectively). The soil at the northern location was a thermic Mollisol (Pullman cl). Experimental variables included two Gossypium hirsutum L. cultivars (Paymaster Dwarf and Dunn 56-C), row spacing (1 and 4 rows/102-cm bed in 1972 and 1, 2, and 4 rows/102-cm bed in 1973), and N application rate (0, 45, 90, 180, and 360 kg/ha). Cultivar did not exert a consistent influence on the petiole NO⁻₃-N concentration measured. The evidence suggested that cultivars found to perform well in narrow row spacings will yield similar petiole NO⁻₃-N concentrations when grown under the same cultural and environmental conditions. Petiole NO⁻₃-N concentration at a given stage of growth decreased linearly as row spacing was changed from 1 to 4 rows/102-cm bed. The effect was greatest during the first half of the growing season on the Brownfield lfs and Amarillo sl soils and during the latter part of the season on the Pullman cl soil. Increasing N application rate increased NO⁻₃-N concentration in the petiole. Most of the quadratic regression equations describing this relationship yielded correlation coefficients significant at the 1% level. Within a year and location, petiole NO⁻₃-N concentration was a sensitive indicator of N application rate..
Sunderman, Herbert Dean (1976). Nitrate concentration in cotton (Gossypium hirsutum L.) petioles as influenced by cultivar, row spacing, and nitrogen application rate on the Texas High Plains. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -613804.