2000 Table of Contents

2000 STEEP III Progress Report

TITLE: Evaluation of Wheat and Pea Cultivars Under Direct and Conventional Seeding in Washington, Idaho and Oregon.

INVESTIGATORS: Stephen Dofing, WSU, Stephen Guy, University of Idaho, Bill Payne, OSU, Kevin McPhee, USDA-ARS and Dave Huggins, USDA-ARS

INTERIM REPORT:

OBJECTIVES:

1. Identify pea cultivars with superior performance under direct seeding.
2. Compare performance of pea cultivars in direct vs. conventional seeding.
3. Determine if the performance ranking of pea cultivars under direct seeding is different from that under conventional seeding.
   

KEY WORDS: Pisum sativum, tillage, yield, no-till

STATEMENT OF PROBLEM:

Conventional tillage practices commonly used in the highly erosive Palouse region of eastern Washington, northern Idaho and northeastern Oregon threaten the sustainability of agricultural production. Reduced tillage and direct seeding into standing stubble provide greater crop residue to protect the soil surface from erosive forces such as spring rain and runoff from snow melt. Significant information is available on the performance of wheat and pea cultivars in conventional tillage conditions, however, relatively little information is available on production under reduced tillage and direct seeding. Results of this study will provide needed information on the adaptability of pea cultivars to these conditions.

ZONE OF INTEREST: Palouse region of Idaho, Washington and Oregon

ABSTRACT:

Conventional tillage practices are a tradition in the Palouse region of the Pacific Northwest, however, the impact on the soil is threatening the sustainability of crop production. Reduced tillage and direct seeding into previous crop stubble (no-till) offers significant environmental benefits for crop production. All pea cultivars currently available to commercial growers have been developed under conventional tillage conditions and with little understanding of their response to no-till conditions. Fifteen to twenty pea cultivars were compared in conventional tillage and no-till conditions in Idaho and Washington during the 2000 crop year. Seed yield was substantially lower under no-till in all trials. Several factors contributed to this including cold, wet soil conditions as well as poor stand establishment and slow crop growth. Karita, Lifter and Joel were among the highest yielding green pea cultivars and Fallon and Shawnee were the highest yielding yellow pea cultivars in the trials. In general, the cultivars with the semi-leafless trait and short vine length were the most upright and easiest to harvest. A direct comparison of performance between conventional and no-till conditions indicated that a significant cultivar by tillage system interaction exists. Further investigation into the effect of the no-till environment on individual cultivars is needed to establish specific breeding objectives. Additional testing is also required to allow solid conclusions to be drawn regarding cultivar adaptation to no-till conditions.

RESULTS AND INTERPRETATION:

Idaho Trials
Cultivar evaluations were conducted at three sites in northern Idaho. No-till trials were sown at the Parker Plant Science Farm near Moscow and east of Genesee in cooperation with Russ Zenner. These plots were sown May 1, 2000 following spring wheat at Genesee and on April 26, 2000 following barley at Moscow using a Great Plains drill with turbo-coulters and double-disk openers. Adequate stands were established at Moscow, but at Genesee, an equipment failure in the seed distribution system funneled seed into only two of the six plot rows and that site had to be abandoned. Twenty cultivars of pea including green, yellow and marrowfat were evaluated in both trials.

The third site in Idaho evaluated 15 cultivars of pea in a replicated no-till (NT) versus conventional till (CT) trial at the Kambitsch farm north of Genesee. The previous crop was winter wheat and conventional tillage involved plowing the stubble. These plots were also sown on May 1, 2000 with the Great Plains drill. Weed control for all the Idaho sites included Pursuit and Assure II. Leaf weevil, seed weevil and aphids were a problem at both sites that were harvested and probably reduced yield despite insecticide applications.

Pea cultivar performance from the Moscow no till trial was evaluated for yield, seed size, vine length and canopy height (Table 1). Vine length can be compared to canopy height to determine lodging or erectness of plants. Lifter, a new release from ARS-WSU pea breeding project was significantly higher yielding (1271 lb/a) than all other cultivars. Lifter has a conventional vine type and would be more difficult to harvest in no-till than the semi-leafless cultivars, but had a 19 inch final canopy height that was OK for harvest in this case. Athos, Badminton, and Karita were the next highest group for yield. Yield and seed size is shown for 14 cultivars that were evaluated in no till in 1999 at two sites and at the 2000 site to give three site years of data (Table 2). Despite a weak performance in 2000, the highest average yield was for Fallon (1389 lb/a), followed by Joel, Shawnee, Karita, and Swing. The marrowfat cultivar Supra has the heaviest seed (largest seed size) as expected, followed by Athos, Jasmin and Karita.

At Genesee, the average seed yield was 1160 lb/a in CT compared to 890 lb/a in NT (Table 3). In NT the pea plants appeared to emerge later and crop development was delayed compared to CT for most of the season. A more detailed growth analysis would be interesting. The highest yielding green pea cultivar in CT was Joel (1532 lb/a), but Karita yielded highest in NT (1290 lb/a). Karita had a smaller yield difference (9%) between CT and NT than average (18%). The yellow pea cultivar that yielded highest in CT was Fallon (1720 lb/a) but Badminton was highest in NT (1309 lb/a). Badminton also showed a smaller difference (6%) between CT and NT than average (27%) and Fallon had a large difference (36%). Seed size was not affected by tillage. Vine length was slightly shorter in NT and canopy height was higher in NT for the long vine cultivars Joel, Columbia, and Shawnee; probably due to the wheat stubble holding up the vines.

It appears that there are different responses for different cultivars in NT versus CT. There was a significant interaction of tillage and cultivar for seed yield and canopy height. Further evaluations of cultivars under tillage comparisons should help in interpreting cultivar by tillage response interactions.

Washington Trials
Two pea cultivar evaluation trials were established at the USDA-ARS Soil Conservation Farm near Albion, WA in established no-till fields. Trial 1 was conducted in a field as part of a two year rotation (winter wheat/pea) and Trial 2 was in a field with a three year rotation (winter wheat/spring barley/pea). Both trials were sown on April 27, 2000 using a custom no-till drill equipped with cross slot openers and harvested on August 22, 2000. The same 20 cultivars evaluated in the Idaho trials were included in the Washington trials. Weed control was accomplished using a pre-plant application of Roundup and Prowl and a post emergent application of Assure II. Insects were controlled with Imidan and Cygon. Stand establishment for Trial 1 was relatively poor due to hair pinning of the seed, but excellent stands were obtained for Trial 2. Yield data and plant type were recorded for both trials.

Average yield for both trials were not significantly different despite the poor emergence in Trial 1 (Table 4). This is likely due to the surviving plants compensating for the empty space by developing branches. PRO8612-2G was the highest yielding green pea overall (698 lb/ac) and in Trial 2, however, NZ4L-25 was produced the greatest seed yield in Trial 1 (790 lb/ac). Shawnee was the highest yielding cultivar overall in both trials (850 lb/ac).

Plant type did not have an obvious effect on cultivar performance, however, those with the semi-leafless trait were more upright and easier to harvest. The cultivars with the conventional plant type tended to lodge and made it difficult to harvest. This response would not make them acceptable in commercial production fields. The overall low yields of these trials is likely due to a combination of factors including cold and wet soil conditions and poor stand establishment. No-till or direct seeding provides many advantages to agricultural production in the Palouse region. Continued evaluation and selection of cultivars adapted to these conditions is required.

Note: Wheat evaluations were not conducted due to a reduced level of funding from that originally proposed. Also, Dr. Stephen Dofing and Dr. Bill Payne have accepted new positions elsewhere, therefore Kevin McPhee has taken the lead for the Washington trials.

INTERACTION (COOPERATION) WITH OTHER SCIENTISTS CONDUCTING RELATED ACTIVITY: None

PUBLICATIONS AND PRESENTATIONS: No publications or presentations have been produced or made at this time.

Table 4. Performance of 20 pea cultivars under no-till conditions at the USDA-ARS Soil Conservation Farm near Albion, WA.

SL = Semi-leafless
N = Normal leaflets
SD = Semi dwarf/short vine
LV = Long vine
Trial 1 was part of a 2-year rotation and Trial 2 was part of a 3-year rotation

Contact us: Hans Kok, (208)885-5971 | Accessibility | Copyright | Policies | WebStats | STEEP Acknowledgement
Hans Kok, WSU/UI Extension Conservation Tillage Specialist, UI Ag Science 231, PO Box 442339, Moscow, ID 83844 USA Redesigned by Leila Styer, CAHE Computer Resource Unit; Maintained by Debbie Marsh, Dept. of Crop & Soil Sciences, WSU