Viability of integrating field peas into organic cereal grain rotations in Maine
The goal of this project was to determine if field peas were a viable option for organic cereal grain rotations in Maine. The common rotation of grain – clover – grain has many benefits as it uses a clover cover crop to break weed and disease cycles, provides fertility to the subsequent crop, and reduces the risk of soil erosion, however this rotation is costly as the clover does not generate actual revenue and the land is virtually out of production every other year. Introducing an annual pulse crop such as field peas would provide many of the same benefits as clover and would also produce a marketable crop that has the potential to generate revenue. This project trialed 4 varieties of yellow field peas to determine if certain varieties were better suited to Maine’s growing conditions.
On May 15 and 16 of 2015, four varieties (AC Agassiz, Jetset, SW Midas, and Nette 2010) of yellow cotyledon, determinate type field peas were planted in Benedicta, Maine. This experiment was configured as a strip trial using a randomized complete block design with 3 replications of each variety. Target populations for all varieties was 348,480 plants per acre (8 plants per square foot). The original target population was 392,040 plants per acre (9 plants per square foot) but was reduced to avoid running out of seed.
Height measurements, disease symptoms, weed pressure, and general crop physiological observations were made throughout the growing season.
Trial was harvested on August 30, 2015 (106 DAP). Replicated strips were harvested from the B and C blocks only. The section of the field that contained block A was unusable for data collection due to the narrowing of the field and co-mingling of varieties. Harvest strips measured 20 feet wide by 1293 feet long (.59 acres), and one strip per variety per block was used to determine yield (1.19 acres of each variety).
On June 25, 2015 I gave an overview of the trial to date at the Aroostook Grain Twilight Meeting at the Aroostook Research Farm in Presque Isle, Maine. This field meeting was attended by approximately 25-30 growers, researchers, and small grain breeders.
The planned field day at the trial site had to be excluded from the outreach portion of this project. In place of the field day, a presentation is being planned for January 2016 at the University of Maine Cooperative Extension Potato Conference as part of an alternative crop project. The presentation for the Maine Grain Conference in March of 2016 is still on schedule.
All field observations and measurements along with harvest yield data have been collected and are in the process of being analyzed.
Overall 2015 was a very good growing season in Southern Aroostook County Maine. The pea crop was planted in mid-May, emerged, and began substantive vegetative throughout a cool, damp June. All varieties began flowering by July 07 and were in full pod by August 01. All varieties dried down similarly and were all harvested at the same time.
Diseases and insects were not problematic for any variety. Weed pressure primarily came from chamomile and wild radish. Areas of the field where the weeds were more problematic were visually noticeably less productive than the less weedy areas.
Prior to harvest, a rain event caused all varieties to lodge. While not all of the field lodged, severity across varieties was similar.
All seed originated in South Dakota and was certified by the South Dakota Seed Certification Service.
Nette 2010 and Jetset varieties visually looked healthier throughout the season. Vigor of these varieties generally seemed stronger than SW Midas and AC Agassiz although weed and disease pressure and vine length were not noticeably different. All varieties tested between 92-97% germination with the exception of AC Agassiz which tested at 84% germination. The low germination of this seed lot could be related to poor overall plant vigor.
Physical yields of Nette and Jetset were higher than those of SW Midas and AC Agassiz. Analyzing the data will determine if these differences are significant.
Assistant Professor of Applied Plant Pathology
University of Maine
174 Hitchner Hall
Orono, ME 04469
Office Phone: 2075812564
University of Maine Cooperative Extension
57 Houlton Road
Presque Isle, ME 04769
Office Phone: 2077643361