Mg. Trivino et Cb. Johnson, Season has a major effect on the essential oil yield response to nutrient supply in Origanum majorana, J HORT SCI, 75(5), 2000, pp. 520-527
The effect of different nutrients on growth and essential oil yield and com
position in Origanum majorana L. were studied under two seasons differing m
ainly with respect to their temperature regimes. Oil composition was little
affected by either season or nutrient regime. Growth rates and yield of es
sential oils were positively correlated with nutrient supply; less strongly
so in the summer than in late spring. Specific oil yield (yield per unit p
lant weight) was generally positively correlated with nutrient level at the
lower temperature, negatively at higher temperature., In both seasons, the
oil yield per plant was closely correlated to the growth rate, regardless
of the nutrient or dose, but the responses differed significantly according
to the season.