Mineral Nutrition of Olearia Phlogopappa: Effect on Growth, Essential Oil Yield, and Composition

Glasshouse grown clonal material from the Australian endemic Okaria phlogopappa Labill. D.C. was studied under various nitrogen (N), phosphorus (P), calcium (Ca), and potassium (K) conditions ranging from 0.5N Hoagland nutrient solution to a four-fold dilution of N, P, and Ca and a three-fold dilution of K. Low N produced the slowest growth rates, but the greatest yield of essential oil/g dry matter. Low P decreased the ratio of monoterpenes to sesquiterpenes, mostly through an increase in the major odour components, kessane and liguloxide. Levels of the nutrients, N, P, K, Ca, and magnesium (Mg), required for optimum dry matter production were 2.3,0.25, 0.4, 0.6, and up to 0.7%, respectively. © 1995, Taylor & Francis Group, LLC. All rights reserved.