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marianum to various levels of IAA to increase the transport of assimilates to sink. Leaf area

increased due to improved phloem loading of assimilates under plant growth regulators.
PGRs enhance the leaf area by increasing cell expansion and cell elongation. Earlier studies

of Mbagwu et al. (2017) found that IAA increased the leaf area in Gongronema latifolium.
Number of leaves increased except at 50 ppm concentration of IAA 20 days of spraying,

in comparison to the control plants. At 60 days of spraying, IAA treated plants has greater
number of leaves. At the later stage of the growth of the plant, leaf number reduced as

compared to the earlier growth stages of plant. Number of leaves increased because IAA is

known to prevent leaf abscission. Bhandari et al. (2009) also reported increased number of
leaves in Verbascum thapsus by treatment with IAA.

Fresh weight of the plant increased as the age of the plant increased. Fresh weight of the

plant improved by the treatment with IAA treatments. This increased fresh weight is due to
differential H2O level in various plant tissues by the supplementation of PGRs. Fresh weight

of the plant increased due to increased leaf thickness and rate of photosynthesis by PGRs.
Vamil et al. (2011) also reported increased fresh weight in Bambusa arundinacea by

treatment with IAA.
It was found that IAA had significant effect in increasing dry weight of the plant. The

higher dry weight in PGRs treated plants is due to variance in the H2O amount as PGRs

influence the membrane permeability for the solute transport and accumulation of
photosynthetic products. Singh (2003) also reported similar results in IAA treated

Catharanthus roseus.
IAA had more effect on increasing chlorophyll content in comparison to control plants.

Present study revealed that there is increase in the chl ‘a’ and total chl content and decrease in
the chl ‘b’ content. Both IAA protects chlorophyll pigment from damage by light and hence

resulted in increased chlorophyll synthesis. Czerpak et al. (2002) found that IAA strongly

stimulates the content of chlorophyll in Wolffia arrhiza.
At 20, 40 and 60 days of spraying, IAA had more influence on increasing phenolic

content. Present results demonstrated that phenol content improved in PGRs treated plants. It

was attributed to the fact that IAA in considered to modify the secondary metabolites
synthetic pathways. Shikimic acid pathway is customized by IAA through alterations in the

phenyl ammonia lyase activity. Mekky et al. (2017) also found that phenol content increased
with IAA treatment in Silybum marianum.

Flavonoid amount is greater in PGRs treated plants. IAA application is helpful in
triggering formation of active constituents and escalation in flavonoid level which defend

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