The performance of spring wheat cultivar mixtures under conventional and organic management in Western Canada

Abstract

Wheat (Triticum aestivum L.) cultivar mixtures may stabilize yield across environments, control air‐borne diseases, and manage pest populations in both conventional and organically managed systems. The objective of this study was to evaluate agronomic and end‐use quality characteristics of wheat cultivar mixtures. Five Canada Western Red Spring wheat cultivars (‘Go Early’, ‘Carberry’, ‘Glenn’, ‘CDC Titanium’, and ‘Lillian’) differing in agronomic and quality traits were selected to compose 20 possible two‐way and three‐way combinations. Field experiments were conducted in four conventional and two organic environments in Alberta and Saskatchewan, Canada in 2016 and 2017. Wheat cultivar mixtures out‐yielded their mid‐component averages in both conventional and organic environments. Averaged across locations, two mixtures, Glenn–Lillian and Go Early–Glenn–Lillian, significantly out‐yielded their mid‐components. The overall yield increase ranged from 3.3 to 14.1%, with a mean of 0.18 Mg ha–1 over different environments. Grain yield was negatively correlated with protein content (r = –.53) and falling number was negatively correlated with sedimentation volume (r = –.66) in conventional systems. Protein content was positively correlated with falling number in both conventional (r = .60) and organic (r = .40) systems. Days to maturity was positively correlated with yield (r = .40) and sedimentation volume (r = .40), but negatively correlated with falling number (r = –.80) in organic system. Sole cultivars were more stable under conventional, and mixtures were more stable under organic management. Our results suggest that wheat cultivar mixtures may provide yield advantage under abiotic stresses in conventional, whereas superior yield and grain quality in organic management.

Winter Wheat Mixtures Influence Grain Rheological and Mixolab Quality

“…Cowger et al (2008) and Mundt et al (1995) reported an average yield increase in winter wheat mixtures but yield increases were relatively small. Similarly, there was no significant difference between single and combination of winter wheat in the study of Chen et al (2020) of 4.06 t ha -1 . For organic spring wheat cultivation, Dai et al (2012) found that the cultivar mixture did not improve grain yield.…”

“…Wheat protein content is a factor to consider when making bread, protein content varies depending on wheat variety, growing area, soil type and quality, and fertilizer input (type, amount and time), particularly nitrogen. According to Chen et al (2020), the protein content was lower in organic farming than conventional farming. Protein content was higher under mixtures of two varieties but the increases were relatively small (0.2%) compared to wheat varieties grown singly in an organic system.…”

Identification of Spring Wheat with Superior Agronomic Performance under Contrasting Nitrogen Managements Using Linear Phenotypic Selection Indices

“…The five breeding methods employed to develop cultivars for organic agriculture are the following: (i) indirect selection under conventional management, (ii) direct selection under organic management in all generations, (iii) selection under conventional management in early generations, followed by selection under organic management in advanced generations, (iv) marker-assisted selection (MAS), and (iv) genomic selection [ 4 , 14 , 15 ]. The University of Alberta Wheat Program, Edmonton, AB, has studied the pros and cons of these methods in diverse spring wheat lines and cultivars evaluated under both conventional and organic management systems, including comparing yield components [ 16 , 17 , 18 ], the performance of sole crop with mixtures [ 19 , 20 ], weed and nutrient competitive abilities [ 8 , 9 , 21 ], breadmaking quality [ 22 ], mapping genes and quantitative trait loci (QTL) associated with agronomic traits [ 23 , 24 , 25 , 26 , 27 , 28 , 29 ], and comparing the prediction accuracies of different genomic selection models [ 30 , 31 ]. Recently, we reported the physical positions of 44 QTLs associated with heading, flowering, and maturity [ 26 ] and 152 QTLs associated with nine agronomic and end-use quality traits in four recombinant inbred line (RIL) populations, which were evaluated under conventional and organic management systems [ 25 ].…”

The effects of wheat cultivar blend on the content of essential grain minerals

“…Scientists from Western Canada [9], with intention of yield stabilizing across environments, control of air-born diseases, and manage pest populations, performed an experiment with five wheat cultivars and 20 their two-way and three-way blends, all this in four conventional and two organic environments. Cultivar mixtures may increase yield (3.3 to 14.1 %) across environments, control air-borne diseases, and manage pest populations in both conventional and organically managed systems, found them.…”

“… Compensation effects -a stronger variety compensates for a weaker or injured variety.  Better disease control due to more different resistance genes involved -management of multiple disease tolerance [3], [4], [5], [6], [7], [8], [9], [10], [11], [15], [16].  Better protection from insect attacks [14].…”