Effects of plant growth regulator application on the malting quality of barley

Abstract

BACKGROUND Lodging can negatively affect yield and quality of barley grain. Synthetic plant growth regulators (PGRs) reduce lodging by producing shorter, thicker, and stronger stems. However, the impact of applying PGRs on malting performance of barley is not known. The objective of this work was to assess the effect of application of three PGRs (ethephon, chlormequat chloride, and trinexapac‐ethyl) in combination with different seeding rates on the malting quality of barley grown in several locations and years in western Canada. RESULTS The kernel weight in PGR‐treated barley was reduced by 1.7% to 6.5% compared with the nontreated grain. Application of PGRs had no effect on the concentration of proteins and germination energy. Seeding rates significantly affected kernel weight, protein content, and germination index (GI), but no interactions between PGRs and seeding rates were observed. The smaller kernels of ethephon‑ and trinexapac‐treated barley showed good hydration and grain modification during malting, as indicated by high levels of starch‐converting enzymes, high Kolbach indices, and low levels of wort β‐glucans. Overall, the fine extract of malt from PGR‐treated barley was slightly lower than that of the control malt; however, the extract reduction was statistically significant only for chlormequat‑ and trinexapac‐treated barley. CONCLUSIONS The application of PGRs had significant effects on kernel plumpness and kernel weight, but the effects of PGR application on the malting quality were generally small and insignificant. The decision of PGRs application on malting barley needs to be considered in combination with potential benefits of PGRs in mitigating lodging and their effects on the agronomic performance of barley. © Her Majesty the Queen in Right of Canada 2019

Application of Plant Growth Regulators on Soft White Winter Wheat under Different Nitrogen Fertilizer Scenarios in Irrigated Fields

“…The stem thickness ranged from 3.5 to 3.8 mm for ORCF-102 and 3.6-3.9 mm for SY Ovation. Different from our findings, the application of PGRs was generally reported to thicken and strengthen stem thickness of cereal crops (e.g., References [32,33]). In general, the treatment without fertilization (N0) produced the smallest stem thickness although no difference was found statistically, because the N supply is not sufficient for promoting the wheat growth in the treatment without N fertilization.…”

“…Meanwhile, the effect of PGR on protein level is highly related to wheat cultivars. Corroborating with our result on ORCF-102, McMillan et al [33] also did not find any effect of PGR on protein levels. No significant differences were found on test weight among treatments (data not shown).…”

Application of Exogenous Phytohormones at Silking Stage Improve Grain Quality under Post-Silking Drought Stress in Waxy Maize

“…In YN7, protein content under control condition was increased by CTK and unaffected by BR and GA, the value under drought condition was decreased by BR and increased by CTK and GA. A study on wheat found that the protein content in grain was unchanged by the application of CTK (ZR) but was increased by ABA [15]. McMillan et al [26] reported that application of ethephon, chlormequat chloride, and trinexapac-ethyl did not affect the grain protein content in barley.…”

“…However, the influence of exogenous phytohormones on the maize grain quality remain poorly understood. The plant growth regulators (ethephon, chlormequat chloride, and trinexapac-ethyl) application reduce grain weight, but their effects on malting quality are generally inconsiderable [26]. Post-anthesis drought reduces the weight and starch content of grains and increases the percentage of large starch granules, and spermidine or aminoethoxyvinylglycine can increase the proportion of small starch granules [9].…”

Genome Assembly of the Canadian two-row Malting Barley cultivar AAC Synergy

“…AAC Synergy has a different parentage from Golden Promise and is a hulled two-row spring malting barley cultivar developed at the Agriculture and Agri-Food Canada (AAFC) Brandon Research and Development Centre, Brandon, MB ( Legge et al 2014 ). With a combination of high yield, good foliar disease resistance and malting quality, AAC Synergy is currently the second most commonly sown two-row malting barley cultivar in Western Canada ( McMillan et al 2020 ). Due to its consistent malting attributes, it has been recognized and added in 2015 to the recommended list of malting varieties on both sides of the border, in Canada by Canadian Malting Barley Technical Centre (CMBTC) and in United States of America by American Malting Barley Association (AMBA) and continues to be part of these lists to date ( CMBTC 2015 and 2021 ; Gribbins 2015 ; AMBA 2020 ).…”