| Abstract: | Abstract Influences of moisture, temperature (T), and photon flux density (L), on the concentrations and contents of macronutrients in 21‐day‐old tissue of four warm‐season perennial grasses were studied. Highest mean concentrations of N, P, and K occurred in dallisgrass (DAL). Lowest N, K, and S concentrations occurred in bahiagrass (BAH). Coastal bermudagrass (COA) was consistently lowest in P concentration. Concentrations of Mg were higher in the Paspalum than the Cynodon species, averaging 4.5 vs. 2.6 g/kg, respectively. Yields generally increased with increasing levels of moisture, T and L. Nutrient concentrations were generally higher at the higher moisture level. Increased growth temperatures most frequently lowered nutrient concentrations, although T was positively related to K, Mg, Ca and S concentrations in BAH and DAL. Linear T effects indicated that N concentrations decreased 0.5 to 1.2 g/kg for each 1°C increase. Photon flux density caused less variation in nutrient concentrations and less consistent effects than did T. Nutrient concentrations most frequently increased with increased L. Effects of T and L were about equally important at the two moisture levels. Nutrient contents generally increased as yield increased even in situations where T and L had negative influences on nutrient concentrations. |
