Effect of Plant Growth Regulator Application on Yield and Quality of Malting Barley.

Effect of Plant Growth Regulator Application on Yield and Quality of Malting Barley

B.D. Tidemann¹, J.T. O’Donovan¹, M. Izydorczyk², T.K. Turkington¹, L. Oatway³, B. Beres⁴, R. Mohr⁵, W. May⁶, K. Neil Harker¹, E.N. Johnson⁷, H. de Gooijer⁸

¹Agriculture & Agri-Food Canada (AAFC), Lacombe, AB, Canada, ²Canadian Grain Commission, Winnipeg, MB, Canada, ³Alberta Agriculture & Forestry, Lacombe, AB, Canada, ⁴AAFC, Lethbridge, AB, Canada, ⁵AAFC, Brandon, MB, Canada, ⁶AAFC, Indian Head, SK, Canada, ⁷Formerly AAFC, Scott, SK, Canada, ⁸AAFC, Coordinating biologist at Scott, SK, Canada.

Barley lodges due to abundant nutrients and adverse weather, which can result in negative impacts on yield, quality and harvestability.  In Europe and elsewhere, plant growth regulators (PGRs) are considered an effective, efficient and economical method of managing lodging.  The effect of PGRs on yield and quality of malt barley is not well studied in western Canada.  Field trials were conducted at five locations across the Prairies from 2014-2016, to determine the effects of ethephon, chlormequat and trinexapac on malt barley.  Multiple seeding rates were also incorporated to examine the interaction of PGRs and seeding rate on CDC Copeland.  Preliminary results indicate high variability of PGR effects on agronomic and quality parameters across site years.  Ethephon and trinexapac significantly decreased plant height in 60% of site years.  Trinexapac significantly decreased lodging when averaged across site years, however, within site years decreased lodging was only significant 20% of the time.  Ethephon detrimentally increased days to maturity and decreased percent plump kernals.  Across site years chlormequat and trinexapac caused non-significant yield increases, while ethephon resulted in a non-significant yield decrease.  Overall, while ethephon and trinexapac often decreased plant height, their ability to reduce lodging was inconsistent and not highly effective.  Additional negative effects, particularly by ethephon, on percent plump and days to maturity indicate that PGR applications may include more risks than benefits in Western Canada malt barley.