farnesene in the roots of both cultivars, but the effect of LS on
the induction of this sesquiterpene was variable between the
cultivars; an increasing concentration was found in cv Parano
and a decreasing concentration in cv Splendid. Temperature
induced a trade-off between root growth and the root concentration
of terpenes in both varieties. The negative effect
of HT on the growth of main root, however, was not compensated
by limonene spraying. Therefore, our results suggest
that limonene application could not be able to improve the
yield of the most heat-sensitive carrot cultivars.
In conclusion, our results showed that stomatal conductance
of both carrot cultivars is affected by limonene treatment
which may indicate that limonene treatment could
improve the ability of carrots to tolerate the environmental
stresses such as heat stress by inhibiting the stomatal
opening. There was no clear evidence that limonene treatment
was able to change the emission of VOCs from the
carrot leaves