Bioaccumulation of silicon and enhancement of cannabis inflorescence yield from fertiliser supplementation with the biostimulants silicate and phosphite

Abstract

ABSTRACT Two fertiliser supplements which have become established within the agricultural sphere for their promotion of resistance to biotic and abiotic stressors, are the non-nutritive biostimulants silicon (Si) and phosphite (Phi). However, within the cannabis sphere, Phi has had limited establishment, and Si is purported to be non-bioavailable in silicate form. The work herein explored the impacts to cannabis (hemp) from application of a biostimulant complex (BC) containing Si (as silicate) and Phi. The results confirmed the bioavailability of silicate, which increased leaf Si by 2.1-fold (p = 0.001). Additionally, BC treatment was associated with a marginally significant reduction to branch length (p = 0.070). Inflorescence yield was increased by approximately 1.2-fold (p = 0.087), whilst volatile and colour quality measures were unchanged. Accordingly, this study provides novel support to the utilisation of Si and Phi in combination for the promotion of cannabis yield without compromising yield quality. Abbreviations: B: boron; BC: biostimulant complex; C: carbon; Ca: calcium; DW: dry weight; EC: electrical conductivity; Fe: iron; FW: fresh weight; GC/MS: gas chromatography mass spectrometry; HS: head space; ICP/AES: inductively coupled plasma atomic emission spectroscopy; IPDM: integrated pest and disease management; L:D: light:dark; Mn: manganese; Mg: magnesium; N: nitrogen; P: phosphorous; PAMP: pathogen associated molecular pattern; Phi: phosphite; Pi: phosphate; PPFD: photosynthetic photon flux density; RH: relative humidity; RI: retention index; RT: retention time; S: sulfur; Si: silicon; Zn: zinc