Objective 1: Determine yield response and identify yield limiting factors of edible legume germplasm when grown under abiotic stress and managed using different production systems. Sub-objective 1A: Assess inoculant effects on winter survivability, root rhizobial biodiversity, nitrogen fixing capacities, and yield of direct-seeded advanced edible winter pea (Pisum sativum L.) cultivars in a winter wheat crop rotation. Sub-objective 1B: Identify novel pea germplasm with cold and drought tolerance, in the presence or absence of Rhizobium, to improve food-grade winter pea production across different agro-ecological environments. Objective 2: Enhance G x E x M to develop biotic stress-resilient edible legume cropping systems that improve sustainable production. Sub-objective 2A: Assess the G x E x M interactions of multiple bean genotypes to white mold under different tillage, fertilization and irrigation practices. Sub-objective 2B: Identify and determine Fusarium root rot genetic resistance and the effect of seed treatments on root rot severity, rhizobial formation and winter survival in winter pea under different agro-ecological environments.
Sub-objective 1A: Hypothesis: Winter peas will interact favorably with Rhizobium inoculants to improve winter survival, seed nutritional qualities, yield, and soil health. Approach: Ten food-grade, cold tolerant, winter peas will be grown at two locations. Presence of Rhizobium inoculant on emergence, root nodulation, chlorophyll content, plant height, root/shoot dry weight, root disease severity, rhizobial diversity, soil nitrogen, seed composition, and seed yield/quality over multiple years will be evaluated. Sub-objective 1B: Goal: Identify novel pea germplasm from worldwide collections useful for improving cold and drought tolerance in food-grade winter pea cultivars. Approach: Pea lines evaluated will be screened for cold tolerance (CT) under natural conditions. Lines with CT will be evaluated for drought and disease tolerance in seven rainfall zones. The five highest yielding lines with the best cold and drought tolerance across rainfall zones will be grown at the three lowest rainfall zones and presence/absence of Rhizobium inoculant on these lines evaluated. Sub-objective 2A: Goal: Identify G x E x M interactions that improve control of white mold disease of bean. Approach: Three tillage (conventional, minimum, and no-till) treatments will be evaluated in alternating strips across a field. Two irrigation treatments, 80 and 100 percent evapotranspiration, will be imposed at flowering through maturity. Eight lines will be assessed across tillage x irrigation combinations. Traits measured will include: emergence, stand vigor, flowering date, canopy porosity, lodging, canopy height, normalized difference vegetation index, canopy coverage, canopy temperature, disease incidence/severity, above ground biomass, yield, and seed weight. Sub-objective 2B: Goal: Identify genetic resistance and fungicidal seed treatment combinations effective against Fusarium root rot (FRR) species impacting winter pea across different precipitation zones. Approach: Twelve winter pea fields from six precipitation zones in Washington will be assessed for FRR at four growth stages and species identified. Pea lines from the Pisum Core Collection and cold-tolerant lines identified in Sub-objective 1B will be screened for resistance to the two major FRR species and association and bi-parental mapping populations used to determine quantitative trait loci associated with the resistance. Four winter pea lines with the best CT, resistance to FRR, and yield will be planted in three precipitation zones in Washington and treated with four fungicidal seed treatments to determine best management practices for FRR.
Substantial progress was made across several sub-objectives, all which address Problem Statement 1A (Sustainable & resilient cropping systems) of Component 1 (Building Agroecosystems for Intensive, Resilient Production via GxExM) of the National Program 216, Sustainable Agricultural Systems Research Action Plan (2018-2022). In support of Sub-objective 1A, which is focused on assessing the effects of Rhizobium inoculant on winter pea productivity, a winter pea research trial was established in Moscow, Idaho, in the fall of 2019. Three hundred soil samples were taken across the research plots to determine pre-plant nitrogen levels in the soil. Ten winter pea varieties were evaluated for fall growth in 2019. In the Spring of 2020, the varieties were assessed for their winter survival by visually rating the plots and also by using a program called “Canopeo” that measures canopy coverage (area covered by foliage) of each plot. In addition, plant samples were taken from each plot in the summer to determine the nitrogen source (soil or Rhizobium) used by the plants.
1. Cold and drought tolerant pea lines identified. Development of autumn-sown dry peas that have sufficient cold and drought tolerance to survive winter and produce high yields in low rainfall zones (10 to 12” annually) is critical for improving crop rotations and soil health. Pea lines (>1000 lines) were screened for drought and cold tolerance in Prosser, Washington, during 2019-2020. We identified more than 500 lines with excellent cold and drought tolerance. Seed quality and yields of these lines will be examined to identify lines that combine resistance to environmental stresses with desirable production traits and can be used as parents for developing improved varieties of autumn-sown peas.