Progress Towards a Dwarf Edible Winter Pea for Companion Planting with Wheat

The approach we've taken with this project has been to elevate our ordinary, homegrown methods of pea breeding to somewhat more rigorous standards in order to clarify both the evidence of progress and the criteria for selection. Our methodological aim has been to utilize a simple experimental approach using easily accessible data based on the human senses, basic measuring tools, ordinary arithmetic, and basic knowledge of pea biology.

Our minimum tillage systems make use of mulches, which favor slugs and some other pests, so we will need to apply Sluggo Plus (Iron Phosphate and Spinosad, OMRI approved) to the beds to thwart the slugs, cutworms, etc., and within the fenced gardens we will be using for this project, chipmunks are overpopulated, so we will need to cover the plantings with wire mesh cones until the seedlings are established to guard against chipmunks digging out the fresh seed, and to prevent sparrow damage to young shoots in early spring. Small populations of valuable pea seed will be grown inside of a hardware-cloth-covered frame to more securely protect from loss of mature or freshly sown seed to rodents.

Irrigation will not exceed the minimum typically used for maintenance of a vegetable garden (about 1” per week), and may be less.

Winter pea seeds will be intercropped with winter wheat in mounded beds, with the peas populating a center row in each wheat bed, wheat populating the outer rows. In this system, peas and wheat tend to begin their rapid periods of growth at similar times in the season, with the peas using the wheat stalks as supports. Wheat is sown rather thickly to promote solid winter ground cover; peas are sown at a rate of one seed per six inches, and are inoculated with a broad spectrum garden legume inoculant at the time of sowing. No fertilizer or compost will be added to the soil, and thorough weeding will not be performed. The major known species of weeds present in the patch will be observed and recorded, but this project will not focus on a detailed assessment of weed density, species, or location within the study areas.

Observations are made at specified points in the peas’ life cycle as to which display the most suitable growth habits and demonstrate the most favorable traits for palatability, productivity, threshability, seed size, and the timing of harvest. Seed from favorable individuals is collected for the next generation. Growth habit observations will include vine length measurements, flower color, timing and sequence of flowering and pod set and maturity, and seed size and type.

Marking of planting areas and some individuals will be done with metal garden tags, writing on the tags done with UV-resistant marker. Marking of larger, vined-out plants will be done with various colors of surveyor’s flagging, with additional writing on the flags as needed. Threshing/winnowing will be done with hand methods, drying will be accomplished by spreading out in room air conditions.

23 select pea seeds from plants that demonstrated both reasonable productivity and short stature during the 2023 dry pea harvest (a semi-edible winter pea grex interplanted with Sirvinta winter bread wheat) were sown in autumn of 2023 inside a rodent-proof "seed sanctuary" at Tangly Woods, which is a Black Locust pole structure covered on all four sides and the top with 1/4" hardware cloth. The hardware cloth is also buried 12" deep all the way around the structure's perimeter. Stock fence cages (4' lengths of stock fence joined into tubes) were hung from the wire wall above the peas to support their growth and encourage straight vining to facilitate data collection (It can be appreciated that counting which pods or flowers pertain to which plants is easier when they are all growing in the same direction).

Our project initiated in April 2024, as growth was just starting for the spring. Data for the 2024 spring green growth season was collected in May, and again in June, shortly before harvest, which was timed to coincide with the Sirvinta wheat harvest. As the project aims for short but productive plants, we measured total maximum plant height from the ground for each plant, measuring the longest of the stems from any given plant. Flower color and number of pods per plant were counted. In June, mature and green pods were both counted. Data was converted to graphs for ease of visual understanding of the results in order to select the most advantageous parents for the next generation. Early maturity, at least moderate productivity, and short stature were the primary considerations when selecting the new parents.

Pods were all harvested in late June 2024, and each plant's pods were placed in an open container in a louvered cabinet in our house to finish drying.

At planting time in autumn of 2024, seed supplies from individuals were grouped by size of seeds, color (yellow versus green), and wrinkled versus smooth shape. The seed samples from the plants that had the best balance of short stature and productivity of seeds were selected for the autumn 2024 sowing within the "seed sanctuary", and preference was given to individuals with large seed size and wrinkled shape, as that shape seems to be associated with sweetness and high palatability (similarly to how the trait functions for sweet corn).

Larger plantings (3 94' beds) outside the seed sanctuary were also sown in order to demonstrate the variety of peas we're seeing from our original crosses and to give opportunity for more favorable individuals to be discovered, but due to experiences from previous years, wherein seed was robbed from the soil after sowing by chipmunks and other rodents, the seeds were not sown in the open, but rather beneath cones of 1/4" hardware cloth fashioned for the purpose. Two seeds were sown per cone, in "hills" 24" apart in a row down the middle of each bed, with Sirvinta bread wheat sown in a circle around each cone, and also in a row outlining the perimeter of each bed. Each bed was sown to a different population:

1. In preparation for establishing the 2025 demonstration plots and for comparison for experimental purposes, we attempted to purchase seed from a yell0w-seeded dwarf winter wildlife forage pea, "NAME", but it was out of stock, and the company substituted "Frostmax", a yell0w-seeded long-vining winter pea. The decision was made to sow one interplanted bed.
2. One bed was sown to the same population of seed that was used in the fall 2023 experimental planting.
3. Another was sown to our general "cover-crop-quality" semi-edible winter pea grex, descended and somewhat selected from our original Austrian Winter Pea/Sugar Snap cross. This serves as a rough form of experimental control.

For demonstration purposes, small plantings of each of our current populations of winter pea that have been selected for snap pea traits and snow pea traits, respectively, were established elsewhere, also under hardware cloth cones.

Informal observations were made throughout autumn germination and growth and winter rosette stage.

With the warming of the weather, it is now time to collect another round of data, this time gauging winter survivability for each population, and also to count how many of the individuals from our winter pea crosses show a ring of pigment around the stem at the base of each leaf. This pigment ring is significant, as it correlates to purple flowering as opposed to white, which also correlates to palatability (white-flowered peas tend to be more palatable, especially as dry peas).

We intend also to sow some Green Arrow bush shelling peas and perform purposeful crosses onto them from the most edible and productive of the dry winter peas we currently have on hand, including FrostMax, in order to make the development of a winter hardy edible pea even more likely.