Effect of Nitrogen and Harvest Stage on the Yield and Oil Quality of <i>Tagetes minuta</i> L. in Tropical India

Abstract

ABSTRACT A field experiment conducted during 1997, and 1998, evaluated the effect of nitrogen application and harvest stage on Tagetes minuta. Application of 100 kg N/ha significantly increased the yields of both main and ratoon crops. Oil content of the plants was maximum at full bloom for the main crop, yields were highest in the ratoon crop. At full bloom, nitrogen application slightly reduced oil concentration. Cis-beta-ocimene content in the oil increased with crop age. Dihydrotagetone, though initially was high, was reduced at flower bud initiation and then subsequently increased. Cis- and trans-tagetones and tagetenones were very low during vegetative growth, increased as the plant matured. Except at flower bud initiation, nitrogen application did not affect the chemical composition of Tagetes oil.