The Effect of 1-Triacontanol on the Growth, Flowering, and Quality of Potted Bougainvillea Plants (Bougainvillea glabra var. ‘‘Elizabeth Angus’’)

Triacontanol (TRIA), a plant growth regulator found in epicuticular waxes can regulates the
physiological and biochemical parameters of bougainvillea as well as many ornamental plants. Many
researchers reported that TRIA treatment improve growth, yield, protein synthesis, photosynthesis,
water and nutrient uptake, nitrogen fixation, enzymes activities, and content of free amino acids,
soluble protein, reducing sugars and biochemical constituents in various crop. TRIA-mediated
increase in dry matter production could influence the inter-relationship between primary and
secondary metabolism, leading to increased biosynthesis of secondary products. Various studies
present strong evidences that application of TRIA applied either to the root medium or to leaves
enhanced the growth and yield of vegetables and other crops, including agronomic and horticultural
crops as well as medicinal and aromatic crop plants under normal and adverse conditions. TRIA
treatments enhance advanced flowering, flower bud number, and blooming rate of bougainvillea.
Similarly, photosynthetic rate, pigment content, quantum yield, and stomatal conductance increase
with TRIA treatments. TRIA increase N, P, and K levels, total soluble solids (TSS) content and sugar
and protein contents in Bougainvillea plants. Furthermore, more flowers, increase in bract weight,
increase longevity, and less leaf abscission are found in TRIA treatment. Phenol and flavonoid
contents, sucrose phosphate synthase (SPS) and antioxidant activities are also markedly increased
with TRIA treatments. However, TRIA treatment reduces the ethylene production treated plants.
There are positive correlations are observed between leaf TSS and flowering time and flower number,
between leaf sugar content and bract weight, and between net photosynthesis and bract growth and
dry matter production. It can be concluded that the foliar spray of TRIA stimulates growth, enhances
flowering, and improves the quality of potted Bougainvillea plants. The present discussion covers the
pivotal role of TRIA in plant growth and development, its mode of action and its significance in
improving the productivity and quality of ornamental crops.