1. Develop commodity and food-type soybean varieties adapted to Minnesota
Variety development is a multi-step process involving crossing between promising parents, inbreeding to create true breeding lines, visual assessment to assess plant health and maturity, and yield and quality trials to generate data that can be used to make selections and identify superior new varieties. Yield trials are classified into preliminary yield trials, new experimental line trials (i.e., advanced yield trials), and regional trials. Regional trials consist of the best lines and are conducted across different states in a cooperative fashion between breeders. Crossing blocks, observation rows, and yield trials are organized based on the intent of the cross (commodity type, SCN resistance, food type, etc.). Planting at over 13 locations is conducted in May. Trials are designed using a randomized complete block design with less than 50 entries to reduce spatial variation within trials. Notes on stand establishment are recorded in June. Crossing and notes on iron deficiency chlorosis are recorded in July. Greenhouse screening of Phytophthora begins in July. Rogueing off-type plants begins in August. Harvest and notes on maturity begin in September. Visual selections on observation rows occur during October. Samples are collected from each plot and measured for protein, oil, and carbohydrate and fatty acid composition during November through March. Data is analysed for purposes of making selections during November through February. Decisions on variety releases occur in December.
A new goal this year is to increased efficiencies and decreased workload under reduced budgets. We will minimize the number of preliminary yield trials in northern MN, remove smaller sites from our northern region, and cooperate more with private partners to grow and manage plots.
2. Conduct public and private variety soybean trials
Each year, the UMN Soybean Breeding program organizes and conducts the Minnesota State Variety trials. Both companies and public institutions are eligible to enter varieties into this trial. The trials consist of two different types: 1) General purpose trial; 2) Special purpose/Food-type trial. The trials are conducted in four zones: far northern, northern, central, and southern. Three locations are planted within each zone. Trials are planted and harvested according to standard practices. Quality and SCN resistance (in the SCN trials) are measured. Results are distributed to the farmers through www.soybeans.umn.edu as well as through MSRPC.
3. Discover and develop new sources of resistance to soybean pests and diseases.
Close collaboration with fellow researchers in plant pathology and entomology creates a dynamic that ties discovery of novel sources of resistance directly with variety development. As soon as putative new sources of resistance are discovered, those sources are included in the UMN Soybean Breeding crossing block. New crosses carrying the new sources of resistance are advanced in the breeding pipeline as described under Objective 1.
4. Collect preliminary data on variation among soybean varieties for early-season canopy coverage as a tool for weed control.
Weed control continues to be a major issue for soybean growers. Early season canopy coverage and rapid canopy closure helps to reduce weed pressure through shading of the weeds. A neglected aspect of variety characterization and breeding is canopy coverage. It’s possible that standing variation for early-season canopy coverage exists among commercial varieties. If varieties could be found that have greater canopy coverage, they could be planted to help reduce weed pressure and become another weed control tool.
Through the support of MSRPC, we have developed good capabilities in collecting image data using unmanned aerial vehicles. From these images we can extract precise data on canopy coverage at any given developmental stage if the fields are flown regularly through the season. We will use these data to quantify the variation that exists among commercial soybean varieties for canopy coverage. If substantial variation exists, we will work with weed scientists and use these data to help design future experiments aimed at determining the benefit of variety selection, for canopy coverage, on weed control.