Effects of applications of N fertilizers and nitrification inhibitors on dry matter and essential oil yields of Java citronella (Cymbopogon winterianus Jowitt.)

Abstract

A field experiment was conducted for 2 years (1993–95) at Central Institute of Medicinal and Aromatic Plants, Field Station, Bangalore, India to evaluate the nitrification inhibitors, benzotriazole, o-nitrophenol, m-nitroaniline and dicyandiamide in a perennial aromatic grass, Java citronella. Citronella responded to applications of high doses of nitrogen (300 kg N/ha/year). The interaction between N doses and nitrification inhibitors was significant. Nitrification inhibitors performed better at the highest N dose (450 kg N/ha/year) and the increase in the essential oil yields was to an extent of 27·3 to 34·6% when compared with ‘N alone’ treatment. The nitrification inhibitors also increased the apparent N recoveries by citronella considerably. The oil content in the herb and its quality were not affected by the treatments. The nitrification inhibitors increased citronella yields and improved N economy.