To investigate the biostimulant effect of protein hydrolysate from shellfish waste on crops,  three hormone-like activity tests were performed on different formulations of shellfish  protein hydrolysate: a) H100, raw hydrolysate, b) DEFAT, defatted by settling and c) F0.45, defatted and filtered at 0.45 µm. The results gave a very weak auxin-like activity, cytokinin-like effect for H100 and DEFAT but no effect for  F0.45, high gibberellin-like activity for the F0.45, negligible for H100 and DEFAT.

The biostimulant effect of hydrolysates can be, at least in part, ascribed to hormone-like molecules (i.e. aminoacids). Plant hormones, or growth regulators, are endogenous molecules that mediate adaptations to environmental conditions. The main plant hormone classes: a) Auxins (3-indoleaceteic acid [IAA] derivatives); b) Gibberellins (gibberellic acid [GA] derivatives); c) Cytockinins (kinetin-like molecules [KIN]). The use of quick-response hormone-like activity tests allows to verify if a protein hydrolysate can exert an effect similar the main plant-hormone classes on crops. This would give previous information on the possible biostimulant activity of the hydrolysate, on the most suitable formulation and on the best dilution ratio at which it can be applied. These quick response test do not replace pot and/or filed trials, but can help to address the proper dose to obtain a biostimulant effect.

 

Futher information: Scaglia et al. (2015) Sci. Total Environ. 514, 314–321; Audus (1972) Chemistry and Physiology vol.1. Leonard Hill Books, London, UK; Pizzeghello et al. 2006 Chemosphere, 65, 190-200; Wang et al. 2001 Chemosphere 44, 1711-172; Pizzeghello et al. 2013 J. Geochem. Explor. 129, 70–75; Tsygankova et al. 2018 Int. J. Chemtech Res. 11, 10, 174-190