Participatory plant breeding (PPB) has the potential to be an alternative to a centralized breeding model for niche markets that are historically underserved. Our objectives were to evaluate the performance of two parental cultivars from a Canadian PPB program: a modern spring wheat (Triticum aestivum L.) cultivar (5602HR) and a landrace (Red Fife)--with the progeny of the cross when selected by two farmers located 1800 km apart (denoted Farm1 and Farm2) and evaluate progeny differences from each other under organic conditions. Red Fife was 18 cm taller, matured 5 days later, and had greater lodging susceptibility, greater seed mass, and 3.5% lower protein concentration than 5602HR. Farmer genotypes were similar to 5602HR in protein concentration and lodging severity, and similar to Red Fife in plant height (14 cm taller than 5602HR) and seed mass. Farmer genotypes did not yield differently from either parent. Farmer genotypes did not differ from each other in most parameters measured; however, Farm1 had greater lodging resistance under high fertility conditions than Farm2 despite similar plant height. This research provides a proof of concept for the role that farmer selectors can play in selecting for positive traits for organic production and provide insight into organic farmers' preferences. The research also demonstrated that using an older landrace (i.e., Red Fife) allowed positive features such as tall stature to be incorporated into the resulting progeny.
Organic farming in extensive production regions, such as the Canadian prairies have a particularly difficult challenge of replenishing soil reserves of phosphorus (P). Organic grains are exported off the farm while resupply of lost P is difficult due to limited availability of animal manures and low solubility of rock organic fertilizers. As a result, many organic farms on the prairies are deficient in plant-available P, leading to productivity breakdown. A portion of the solution may involve crop genetic improvement. A hypothetical ‘catch and release’ wheat ideotype for organic production systems is proposed to (i) enhance P uptake and use efficiency but (ii) translocate less P from the vegetative biomass into the grain. Root traits that would improve P uptake efficiency from less-available P pools under organic production are explored. The need to understand and classify ‘phosphorus use efficiency’ using appropriate indices for organic production is considered, as well as the appropriate efficiency indices for use if genetically selecting for the proposed ideotype. The implications for low seed P and high vegetative P are considered from a crop physiology, environmental, and human nutrition standpoint; considerations that are imperative for future feasibility of the ideotype.
Interest in intercropping semi-leafless field peas (Pisum sativum L.) is increasing as a means of weed control in organic production. We evaluated field pea (cv. CDC Amarillo) grown alone or intercropped with three seeding rates of either barley (Hordeum vulgare L.), mustard (Brassica juncea L.), or oat (Avena sativa L.). A full seeding rate of field pea was used in each instance, resulting in an additive intercropping design. Each crop combination was conducted in a separate experiment, three times over two years (2019 and 2020) in Carman, MB. Measurements included crop and weed biomass production, grain yield and quality, and net return. Intercrops reduced weed biomass at maturity from 17% to 44% with barley and oat being more suppressive than mustard. Intercrops also reduced field pea yield from 6% to 26%, but increased field pea seed mass. Barley at the high seeding rate provided the most weed suppression per unit of field pea yield loss (2.62 kg of weed suppression per kg of field pea yield loss) compared with oat (1.29) and mustard (0.87). Barley and mustard intercrops decreased net return compared with monoculture field pea. Under low weed pressure (1150 kg·ha−1 weed biomass at maturity) and earlier seeding, oat intercrops reduced net return. However, under weedy conditions (2649 kg·ha−1) and later seeding, field pea-oat intercrops significantly increased net return. In conclusion, while all three intercrop mixtures reduced weed biomass, reductions in field pea yields were observed, and net return benefits were observed only in certain circumstances.
AAC Kongsore is a white-hulled spring oat ( Avena sativa L.) cultivar selected and developed under organic management. AAC Kongsore had high yields under organic and conventional production systems, compared to check cultivars (AAC Oravena, Leggett, AC Morgan and CDC Dancer). AAC Kongsore has good physical and milling quality traits.
Selecting crops that express certain reproductive, leaf, and root traits has formed detectable, albeit diverse, crop domestication syndromes. However, scientific and informal on-farm research has primarily focused on understanding and managing linkages between only certain domestication traits and yield. There is strong evidence suggesting that functional traits can be used to hypothesize and detect trade-offs, constraints, and synergies among crop yield and other aspects of crop biology and agroecosystem function. Comparisons in the functional traits of crops vs. wild plants has emerged as a critical avenue that has helped inform a better understanding of how plant domestication has reshaped relationships among yield and traits. For instance, recent research has shown domestication has led important economic crops to express extreme functional trait values among plants globally, with potentially major implications for yield stability, nutrient acquisition strategies, and the success of ecological nutrient management. Here, we present an evidence synthesis of domestication effects on crop root functional traits, and their hypothesized impact on nutrient acquisition strategies in organic and low input agroecosystems. Drawing on global trait databases and published datasets, we show detectable shifts in root trait strategies with domestication. Relationships between domestication syndromes in root traits and nutrient acquisition strategies in low input systems underscores the need for a shift in breeding paradigms for organic agriculture. This is increasingly important given efforts to achieve Sustainable Development Goal (SDG) targets of Zero Hunger via resilient agriculture practices such as ecological nutrient management and maintenance of genetic diversity.
Long-term agricultural studies contribute to knowledge in ways that short-term projects simply cannot. In this chapter, we highlight some observations from the Glenlea long-term crop rotation study, Canada's oldest organic field crops experiment initiated in 1992. We then discuss how this knowledge has been used to build capacity in organic crops and soils research, student training, and education of farmers and advisors. The main nutrient management challenges discovered at Glenlea regarded phosphorous (P) depletion in the organic hay export system and lack of nitrogen (N) in the organic grain-only system. Capacity development to address these challenges included intensive research on new innovations in legume-based green manure systems, development of a tool for assessing P sufficiency in organic systems, and development of a second tool for budgeting nutrients in whole rotations. We have taught the lessons from Glenlea to approximately 300 students and have embarked on "Organic Agronomist Training," where over 160 advisors and farmers are given information and trained using our tools. The Glenlea long-term rotation continues to be critical to develop capacity in the organic grain and forage sector in Canada.
Involving farmers directly in early‐generation selection may contribute to the development of well‐adapted organic wheat (Triticum aestivum L.) germplasm. This project involved a partnership between a professional breeder and farmers. Progeny from 19 spring wheat crosses were distributed to eight organic farmers (three populations per farmer) in southern Manitoba, Canada. Each farmer selected for three consecutive years, resulting in 23 unique advanced lines. The farmer‐selected lines were compared with eight registered cultivars and one landrace cultivar in replicated field experiments at a total of three site years in 2014 and 2015. Although there was significant variation in agronomic performance of different farmer‐selected lines, the farmer selections were generally taller, later maturing, more susceptible to lodging; farmer selections were higher yielding than the check cultivars at one site‐year. When selecting from the same population, farmers produced distinctively different lines; differences were observed in disease response, days to maturity, height, lodging, and yield. The highest yielding wheats included farmer‐selected lines, a heritage cultivar, and two modern checks, one bred for organic conditions and one with a unique insect resistance trait. This preliminary study shows the potential of farmers working together with a professional breeder to produce wheat germplasm for organic production. Results also confirm the value of certain conventional cultivars to organic production.
Most non-genetically modified (GM) soybean (Glycine max Merr.) cultivars are bred and performance tested under conventional conditions and have rarely been tested in organic production. Twelve non-GM soybean cultivars were evaluated in weed-free and weedy conditions on 5 organic farms and 1 transitional farm in southern Manitoba in 2014 and 2015. The mean cultivar yield ranged from 1384 to 1807 kg ha(-1). Weed biomass at soybean maturity ranged from 1289 to 2553 kg ha-1 and was significantly affected by cultivar. Significant site-cultivar interactions were observed for soybean biomass, height, and yield. Site accounted for 72.4% of yield variability; cultivar accounted for only 1%. Our hypothesis that cultivars with greater early season height are more competitive with weeds was not supported. Yield loss due to weeds ranged between 20 and 44%; lower yield loss was associated with timely weed management. Partial least squares regression was used to assess the main factors controlling grain yield. Higher soil nitrate (N) status negatively impacted final grain yield in this study, suggesting that soil nutrient status impacted the soybean cultivars' competitive ability against weeds. Results suggest that weed management and soil N status are of equal importance to cultivar choice for successful organic soybean production in Manitoba. (C) 2017 Elsevier B.V. All rights reserved.