Critical Thinking

Means × irrigation were significant on saponin content

Means inflorescence yield of Borage in the second year was 7.6%
less than the first year (Table 4). Moderate (I3) and severe water
stress (I4) reduced inflorescence yield 10.3% and 17.7% compared with
well watering (I1), respectively. There was no significant
difference between two former and also between two latter irrigation treatments
(Fig. 2A). Plants from primed seeds had more inflorescence yield compared to plants
from unprimed seeds. Seed priming led to 11.6% to16.8% increase in
inflorescence yield of Borage. However, inflorescence yield of plants from
primed seeds with water (P2), KNO3 (P3) and KH2PO4
(P4) was similar (Fig. 2B).Since the measurement of the content of secondary
metabolites was performed after the completing the second year, part of the
differences between the metabolites content in two years can be attributed to
the effect of the storage period on these compounds.Based on the combined analysis of variance of data, effect
of year and interaction of year × irrigation were significant on saponin
content of leaf and inflorescence. There was no significant difference between
different levels of irrigation and seed priming. However, saponin content of
leaf and inflorescence were also significantly affected by year × priming and
year × irrigation × seed priming (Table 3).3.2.1. Saponin content The mean saponin content of borage leaves in the
first year was significantly higher than the second year. In both years, leaves
of plants irrigated with 120 mm (I3) and 150 mm evaporation
intervals (I4) had more saponin content compared to plants irrigated
with 60 mm (I1) and 90 mm evaporation intervals (I2),
that this superiority was considerable in the first year (Fig. 3). In the first
year, leaf saponin content of plants from primed seeds under I1, I3
and I4 was higher than those plants from untreated seeds, in which
seed treatment with KH2PO4 let to production of leaves
with the highest concentration of saponin. Leaves saponin content of plants
from primed seeds under mild stress (I2) was lower than other
irrigation treatments (Fig. 3A). While in the second year under all of the
irrigation intervals, the saponin content of Borage leaves of the plants from
primed and unprimed seeds was statistically similar (Fig. 3B).