Dengjin Bing, PhD, Lacombe Research and Development Centre, Agriculture and Agri-Food Canada
Field pea (Pisum sativum) is the most widely grown pulse crop in Canada, and Canada is the leading producer and exporter of field peas in the world. Breeding for improved field pea varieties for Canadian pulse growers is an integrated part of the Agriculture and Agri-Food Canada (AAFC) cereals and pulse research strategy. In this article, I will describe the major breeding activities and their status. In particular, I will present the relevant information on pea varieties the AAFC field pea breeding program has developed to assist producers in choosing appropriate varieties for production.
The breeding program has developed varieties of six market classes, including yellow, green, maple, marrowfat, red (also known as orange) and forage (Figure 1). Since early 2000, 30 varieties have been released to Canadian and U.S. markets from the program (Table 1). These varieties include 20 yellow, four green, two maple, two marrowfat, one red and one forage pea. Producers interested in a particular type can contact the licensee(s) of that variety.
The primary breeding objectives for all market classes are high yield, good harvestability (good standability and low pod-shattering), resistance or tolerance to major field pea diseases, including powdery mildew, mycophaerella blight and fusarium wilt, and good seed quality.
This breeding has resulted in gradual but steady yield improvements in all market classes. However, in general, the higher yield is positively associated with later maturity (Figure 2) and taller plant height (Figure 3). To capitalize on the maximum yield advantage, producers may choose taller varieties with appropriate maturity in their production regions.
Good lodging resistance (aka standability) is an important characteristic of a superior field pea variety since it facilitates harvest and reduces dockage of harvested grains (Figure 4). No clear relationship between yield and lodging has been found in the AAFC varieties. This may be related to the fact that these varieties have been selected for improved standability. The majority of varieties have a pre-harvest lodging score of 2.4 to 4.8 on a 1–9 scale, and there is little difference among the varieties.
Seed size is also a significant factor to consider when choosing an appropriate variety to grow. Small seed size can reduce the seed cost at planting, but a large seed size of good quality can have a market premium. The seed size of the AAFC pea varieties varies greatly depending on the market classes. For the marrowfat varieties, the thousand seed weight (TSW) is greater than 340 g. For the yellow pea varieties, the TSW ranges from 190–288 g and in general, high-yielding varieties have a TSW around 220–250 g. However, it should be noted that the seed size is variety-specific, and environmental conditions significantly influence it.
All of the AAFC field pea varieties are resistant to powdery mildew and moderately tolerant to mycophaerella blight and fusarium wilt for disease resistance. In production regions with prevalent mycophaerella blight and fusarium wilt, appropriate disease management should be expected.
In addition to the aforementioned breeding objectives, this program has been breeding for improved protein content for several years. In recent years, the program has increased its efforts to develop varieties with improved resistance or tolerance to root rot. However, these are very challenging breeding objectives and have yet to result in commercial varieties.
The AAFC field pea breeding program has been strongly supported by Alberta, Saskatchewan, and Manitoba’s pulse producers. The current breeding activities are funded through the Canadian Agriculture Partnership-Pulse Cluster program. This strong support has been essential for the program’s success in the past and in coming years, and is greatly appreciated.