Exogenous phytohormones regulate productivity, antioxidant and photosynthetic response of different growth strategy crops

Plant phytohormones participate in regulation of all aspects of plant development and plays a key role in the adaptation processes during biotic and abiotic stresses.
The impact of exogenous phytohormones on different growth strategy plants yield, antioxidant and photosynthetic response was evaluated.
Lettuce (Lactuca sativa L.) ‘Green Cos Lobjoits’ was grown in a greenhouse with 16-h photoperiod, 70% humidity and average temperature of 21-22°C during the day and 15-17°C at night was maintained.
Pea (Pisum sativum L.) ‘Respect’ was grown in a vegetation area with a shed during May-July season (lat. 55°, Lithuania). A combination of two phytohormones per treatment was chosen from five different phytohormones (kinetin (KIN), indole-3-acetic acid (IAA), gibberellic acid (GA₃), abscisic acid (ABA) and salicylic acid (SA)) at 30 mg L^‑1 concentration of each.
The combination of exogenous phytohormones were applied at critical development stages: at 12-13 BBCH-scale for lettuce and at 14-16 and 51-55 BBCH-scale for pea.
Analysis were performed after 5 days of each application and at technical maturity.
Results showed that the response on selected combinations of phytohormones depends on plant growth strategy.
Thus, the proper application of phytohormone based biostimulants improve antioxidant and photosynthetic response and results the increase of plant productivity.

International Symposium on Models for Plant Growth, Environments, Farm Management in Orchards and Protected Cultivation – HorchiModel2023

M. Urbutis, G. Samuolienė

lettuce, pea, biostimulants, productivity, onthogenesis

https://doi.org/10.17660/ActaHortic.2025.1425.34