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

Project Overview

FS24-368
Project Type: Farmer/Rancher
Funds awarded in 2024: $18,486.00
Projected End Date: 03/31/2026
Grant Recipient: Tangly Woods
Region: Southern
State: Virginia
Principal Investigator:

Commodities

  • Agronomic: peas (field, cowpeas), wheat
  • Vegetables: peas (culinary)

Practices

  • Crop Production: crop improvement and selection, plant breeding and genetics

    Proposal summary:

    By breeding established winter pea varieties with other pea varieties prized for their edibility and selecting from the resulting offspring, a more usable and versatile winter pea might be developed. Furthermore, if either by crossing those strains with a dwarf variety, or by selecting any dwarf specimens that may appear amongst the heterogenous mix
    of phenotypes that emerge from the succeeding generation of the original cross, a successful edible dry pea to sow as a companion with wheat crops might be developed.

    Several years ago, we at Tangly Woods saw the potential for making this kind of progress in the breeding of winter peas, and grew a small patch of the Austrian winter pea immediately adjacent to a small patch of Sugar Snap peas in the hopes that they would cross. The next year’s Sugar Snap planting had a few individuals with purple (instead of white) flowers, and less succulent pods, clear evidence of crossing. The seed from those individuals was planted in fall to
    test for winter hardiness. Many of them were winter-hardy, and since then we’ve been selecting the most palatable of the
    resulting population of winter peas, even replacing our old Austrian winter peas in the wheat plantings with the more edible version. Unfortunately, the vines were still usually too heavy for the wheat to support on its own.

    This year, however, at wheat harvest time, after the pea vines had already been extracted from the standing wheat for separate threshing, a few pea vines were discovered that had escaped earlier notice, as they were half the length of the rest, and had not caused the wheat to bend significantly. These vines appeared to be about as healthy and productive of dry peas as the longer vines, but either through genetic dwarfism, growth restraint through simultaneous flowering/fruiting, or another, unknown mechanism they grew more moderately. These individuals were harvested, threshed, and stored separately from the other peas. Some of them have been planted this fall in a location safe from rodents and birds in anticipation of amplification of the seed supply.

    If, over the course of several generations, the short-vining trait can be brought to predominance in this sub-population of our large-seeded, palatable winter peas without sacrificing productivity of dry pea seeds (and possibly edible pods), non-shattering trait, and threshability, the possibility would then–after seedstock amplification–exist for winter wheat and winter peas to be grown together on any scale, with viable dry crops of each of the two being extractable from the mixed harvest. Soils could benefit greatly from this arrangement, and feed millers could have a regional option for acquisition of non-soy leguminous proteins.

    In late 2022, USDA’s ARS released three new winter pea varieties intended as a dry pea for human food. Bred by Rebecca McGee of WSU, they were the first of their kind. It is unclear to us whether these varieties carry the dwarfing trait or not; the press releases didn’t contain descriptions with that level of detail. But even if they are, we think it wise to pursue development of our peas here in Virginia’s Shenandoah Valley, so that our selection process will favor adaptation to Southeast regional growing conditions. We have been unable to find a source for seed of Ms. McGee’s varieties, but if we could, a side-by-side trial would be advisable once our pea’s traits have been stabilized. 

    Project objectives from proposal:

    Grains and dry legumes are currently grown at Tangly Woods and Silver Run Forest Farm as soil-improvement and consumable crops on a home scale. As such, we use minimum tillage, low-input hand methods for soil work, sowing, harvest, and processing. While not practicable for commodity crops on a large scale, our methods are well suited to the close observation required for crop seed development, and approximate the conditions found in no-till dry seed crop cultivation systems. Irrigation will not exceed the minimum typically used for maintenance of a vegetable garden (about 1” per week), and may be less. Irrigation rates will be recorded, as well as a basic observation of natural rainfall.

    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 until the seedlings are established to guard against chipmunks digging out the fresh seed. 

    Soil tests will be performed before the 2024 sowing of the 2025 crop and after harvest.

    Small populations of valuable pea seed will be grown inside of a hardware-cloth-covered frame to protect from loss of mature or freshly sown seed to rodents.

    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 will be 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. Plants will be marked accordingly and the seed of favorable individuals collected for the next generation. Growth habit observations will include vine length measurements at key points in the growth cycle. During flowering, observations will be made as to which plants appear to be flowering more sequentially and which more simultaneously in order to ascertain which plants may be more likely to ripen their dry peas simultaneously. Total yield of dry peas per plant will be recorded for the favorable individuals from the 2024 seed collection.

    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.

    Currently this winter pea population shows some variability as to pod type in the green stage, with snow-, snap-, and shelling-type pods all appearing from time to time, containing various amounts and coarseness of fiber in the pods and fresh peas. Low/less-coarse fiber and agreeable flavor in the tendrils, green pods, and green peas seems to us to be associated with high palatability of the dry peas for human consumption. In the interest of developing this pea population for use as both animal feed and human food, taste testing will be performed on the plants when pods are in the green stage (community members will be invited to help with this analysis). To preserve the possibility of future explorations of the potential for vegetable pea crops of each of these types to be grown in overwintering patterns alone or in polyculture with grains, the plants will be categorized as to their pod type and attempts made to split the populations into groups that breed true to type. However, the emphasis of this project will be the development of a dry seed producer, so any plants that are favorable with regards to green pod stage vegetable production, but less favorable for dry seed production, will be removed from this project’s population and saved for separate pea breeding efforts with vegetable production foci, as traits for prime vegetable production from immature pea fruits and traits for prime dry green pea production may turn out to be mutually exclusive, at least for the edible podded types.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.