ISSUE 1   May 14, 2009

FIELD PEA

Field pea (Pisum sativum L.), a native of southwest Asia, was among the first crops brought under cultivation. The largest acreages of field pea in the US are in North Dakota, Idaho, Oregon and Washington. The green and yellow-seeded varieties (see table) are used for human consumption as dry split field pea. Field peas are also used as protein concentrates for livestock and are pigeon feeds. In North Dakota, pea yields equal those obtained by hard red spring wheat.

Field pea can also be used as a forage crop for hay, pasture or silage. Field pea grown in a mixture with oat, barley, or triticale yields more dry matter per acre than a straight pea crop.

Field pea stems grow to a length of two to four feet. A true leaf consists of one to three pairs of leaflets with a terminal, branched tendril. Flowers are reddish-purple or white. Pods are about three inches long and contain four to nine seeds.

A cool growing season is necessary for optimum pea yields (a mean temperature of 55 degrees to 65 degrees F). Hot weather during flowering may result in reduced seed set. In North Dakota, field pea take about 60 days from seeding till flowering and 95 to 100 days to maturity. Select a variety that is suitable for your farm operation and marketing strategy (see table).

The moisture requirement for field pea is similar to that for cereal grains. Field pea can be grown on a wide range of soil types, but there must be good drainage, as field pea does not tolerate saturated or soggy conditions. Field pea can be grown in a no-tillage or conventional tillage cropping system. It grows best when seeded into a weed-free seedbed in fertile soils. Land preparation for seeding is similar as for wheat. In order to obtain good soil to seed contact, seedbeds should be firm. Avoid seedbeds with large clods. Do not work the soil too fine, or subsequent soil crusting following rains may cause poor emergence. Level ground is critical for easy harvesting of peas. Stony fields should be avoided or rolled after seeding to bury loose stones that otherwise might be picked up in swathing and harvesting. Drill the pea seeds one to three inches deep, in rows six inches apart, as early in spring as feasible. Soil should not be excessively wet at seeding. Seeding can be done with an air seeder or grain drill. Adjust the seeder to prevent cracking of the seed, especially of the large-seeded varieties, since cracked seed will not germinate. Do not pack or roll immediately after seeding if soil moisture is high or excess compaction or crusting can occur.

Pea seedlings can withstand considerable frost. Even if the frost is severe enough to kill the main shoot, the pea plant will re-grow from buds at one of the nodes at or below the soil surface, but this will delay plant maturity.

Field pea is capable of utilizing bacterially fixed atmospheric nitrogen. The specific bacterial association for nitrogen fixation in field pea and lentils is with the bacterium Rhizobium leguminosarium, which is a different bacteria species than is used for soybean inoculation. If field pea is to be grown in a field for the first time, or no peas were grown there recently, inoculation of the seed with the proper Rhizobium prior to planting may increase nodulation. Pea seed germination rate increases with increasing temperature, but at temperatures greater than 64 degrees F, the percentage of seed germinating decreases. Seed treatment with a fungicide can significantly improve emergence. Fungicide labels should be checked to see if a particular fungicide can be used on field pea. This cool-season legume crop fits well into small grain rotations.

For more pea production information see

www.ag.ndsu.edu/pubs/plantsci/rowcrops/a1166w.htm.

For variety selection information see

http://www.ag.ndsu.edu/pubs/plantsci/crops/a1105.pdf.

Hans Kandel
NDSU Extension Agronomist, Broadleaf crops
hans.kandel@ndsu.edu

 

EVALUATING WINTER WHEAT STANDS

Winter wheat was seeded on 530,000 acres last fall and the most recent USDA report indicates that 490,000 of these acres will be harvested. These data suggest that less than 10% of the planted acreage will be lost to winter kill, flooding or poor emergence. Most reports I have received indicate that winter survival of winter wheat was good except where snow cover was minimal. Winter wheat growth has been slow this spring due to unusually cool weather, so now is a good time to evaluate plant stands. The key questions that will be covered in this article are: how to evaluate a stand of winter wheat, what constitutes an adequate stand, and what to do if stands are found to be less than adequate?

Making an accurate assessment of your stand. A first glance, plant stands can look much worse than they really are. There are times, however, when a crop stand is actually worse than it might appear at a distance. If plant stands are not uniform within a field, focus only on those areas of the field that will likely need to be replanted. Take plant counts from 4 or 5 randomly selected areas (use a 1 square yard quadrant or something similar).

What constitutes and adequate stand? Sparse stands will be low yielding and will likely become weedy. If stands are not too low, however, winter wheat has a remarkable ability to compensate for reductions in plant numbers by producing more tillers, particularly in a cool spring like this year. For winter wheat, consider replanting when stands are below 5-10 plants/ft2. Given the lateness of the season and the fact that winter wheat is probably the best thing going in most farms this spring (it is in the ground and growing), and given the amount of planting of other crops that still remains, I would suggest keeping a crop even on the lower end of the range indicated above.

What to do when stand are inadequate? For fields with small patches of poor stands, the best option is probably to leave the field and do a good job of weed control. For fields with very large patches with few or no plants, planting something to reduce weed growth and soil erosion is recommended. Some farmers have reported good results from planting spring wheat to fill in such gaps. Nevertheless, spring wheat matures later than winter wheat so harvest can be problematic. Furthermore, mixing wheat classes can cause problems at the elevator. Planting winter wheat into large gaps can also be an option. Winter wheat planted in the spring will not vernalize so it will not produce a head, but will provide ground cover until harvest. For entire fields that need replanting, we are fast approaching the last planting date for full insurance coverage for spring wheat and barley and yields will likely be low when planting is delay beyond the end of May. Nevertheless, when replanting with spring wheat, use a higher seeding rate (1.6 million seeds per acre) to compensate for the lack of tillering and plant an earlier maturing variety. Planting small grains after June 21 is not recommended. Check with your crop insurance agent before destroying your winter wheat field.

Joel Ransom
Extension Agronomist for Cereal Crops
Joel.ransom@ndsu.edu  

 

SOIL TEMPERATURE AND SUGAR BEET SEED EMERGENCE

Sugar beet seeds germinate and emerge over a wide temperature range in the presence of adequate soil water and oxygen supply. In most years, soil temperature at the 4 inch depth at planting time in mid-April is about 45 F. A soil temperature of at least 38 F is required to initiate germination. Seeds should be planted into seedbeds where conditions are favorable for the seeds and seedlings during germination, emergence and early crop establishment. Planting should be done at a time that will facilitate early emergence and uniform and rapid growth of seedlings.

Wet conditions in April have delayed planting. Do not be tempted into planting into muddy fields. Planting in May when the soil is warmer with adequate moisture will result in faster germination and emergence. In 2006, American Crystal Sugar Company had their largest sugarbeet crop most of the planting was in early May!

The following table gives approximate days to emergence at different soil temperature ranges.

Soil Temperature ( F)

Days to Emergence

38-45

21 days or more

45-52

10-21 days

52-60

7-12 days

60-70

5-7 days

 

PROJECTIONS FOR 2009 SUGARBEET CROP

The total sugarbeet acreage in the US for 2009 is projected at about 1.15 million acres.

Sugarbeet acreage in North Dakota and Minnesota will be slightly higher than last year. American Crystal Sugar Company will plant about 420,000 acres, Minn-Dak will plant 115,000 acres, and Southern Minnesota Beet Sugar Cooperative will plant 116,000 acres. Growers in western North Dakota will produce 24,000 acres of sugarbeet that will be processed in Sidney, Montana. This means that North Dakota and Minnesota will plant just over 675,000 acres of sugarbeet which is about 59% of the US sugarbeet acreage.

Growers will be continue their efforts at improving efficiency by properly preparing seed beds, using starter fertilizer, using adequate seeding rate to start with a good plant population to give their crop a good foundation. Most fields - over 90% - will be planted to Roundup Ready sugarbeet so timeliness of glyphosate applications will be critical. Seeds should be planted into dry or moist seedbeds; growers should not be in a hurry to plant into wet and cold seedbeds.

I encourage all growers to adopt best management practices to have a profitable sugarbeet crop in 2009.

Mohamed Khan
Extension Sugarbeet Specialist
NDSU and University of Minnesota
Mohamed.khan@ndsu.edu


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