NDSU Crop and Pest Report

Plant Science

ISSUE 1  May 1, 2003



This year many North Dakota farmers face dry surface conditions as they set about seeding their crops. Dealing with such conditions isn't easy.

Whether fields are dry or not, farmers should stick as closely as possible to the recommended planting schedule for each crop. Late planting can sharply reduce yields of small grains, flax, corn, dry peas, canola and mustard, especially in a year when temperatures are above normal and spring planting operations ahead of normal.

Under dry seedbed conditions it is true that planting on schedule may result in uneven stands.

But this is preferable to planting too late. If rains do come later, most seeds will still germinate if adequately protected with a seed treatment. Some soil crusting could present a problem if seeds are slow to germinate, so farmers should be aware of this possibility.

To minimize dryness problems, till at a shallow depth and cut down on seedbed operations before planting. Direct seeding or no-till may be the best option this year in many extremely dry regions of North Dakota. It’s also suggested that postemergence herbicides be used rather than preplant soil-incorporated herbicides that can cause additional soil drying and may not be as effective in dry soil.

"Plow pony press drill planting should be at a shallow depth. Roots will not grow through dry soil even if seeds germinate. Use deep furrow hoe drills when available to reach soil moisture. Small grains and flax can be drilled directly into standing sunflower or soybean stubble with disc opener drills."

A double disc drill, is not as effective as a notill drill, a hoe drill or a narrow tine equipped airseeder in seeding to moisture in standing stubble. It perhaps would be beneficial in harrowing first and scattering the straw of previous crop residue prior to seeding.

"If newly emerged weeds are present, use a nonselective, burn-down herbicide before seeding." Some residual weed control may be present from dinitroaniline herbicides (Treflan, Prowl or Sonalan) used in 2002 if it was extremely dry in your area but be ready to spray and control volunteer sunflowers or other crop volunteers if they emerge with the crop.

Here are 10 suggestions to minimize effects of planting into dry soils:

  1. Avoid excess tillage prior to planting. Each tillage operation causes soil moisture losses (1/3 to ½ inch).
  2. Use shallow tillage (3 inches or less) to destroy weeds and firm the seedbed.
  3. Avoid use of premerge soil-incorporated herbicides on crops where post emergence herbicides are available and economical to use.
  4. Plant small grains directly into standing sunflower stalks, soybean, canola and dry edible bean stubble.
  5. Crops like corn, sunflower, field peas and dry edible beans can be planted deeper (2 to 3 inches maximum). Flax, mustard, canola, proso millet, or buckwheat which all should be 1 inch or less in planting depth. Intermediate planting depths of 1 to 2 inches is best for wheat, durum, barley, oats, lentils and soybeans.
  6. In general, large-seed-sized varieties of wheat or durum, oats and barley can be seeded slightly deeper than small-seed-sized varieties.
  7. Seed treatments on small grains should be uniformly applied at labeled rates to maximize seedling emergence. Over treatment on some seeds and little to none on others can cause erratic stands.
  8. If rains come after planting, watch for soil crusting. Break soil crusts with light harrowing or rotary hoe.
  9. Consider post plant applications of nitrogen in the form of urea if good moisture conditions develop later. Rain is usually required in 48 hours after application to reduce N losses due to volatilization.
  10. If fairly good stands are established, but dry soil conditions continue, plan a good weed control program to help conserve soil moisture for crop growth and development.



Sunflower is commonly grown as a dryland crop. There has been some inquiry on irrigated sunflower. Research and farmer testimony has demonstrated that sunflower responds to irrigation with yield increases of 100 to 200% over dryland yields common on droughty soils and in extremely dry years. Sunflower adapts to a wide range of soils and climatic conditions. Low yields may be caused by any of the following: incorrect plant population, poor soil fertility, lack of weed control, diseases, insect damage, bird depredation, lodging, late planting and harvesting losses. Management of all factors listed plus sound water use and management is a must.

Average yields of 26 sunflower hybrids and varieties at the NDSU Carrington Irrigation Research Station in the late 70's were 3,222 lb/A for irrigated sunflower vs. 1,126 lb/A for dryland sunflower (Table 1). These average yields represent a 196% yield increase of irrigated over dryland sunflower. During another year white mold caused yields of irrigated sunflower to be similar to dryland yields (Table 2). Rainfall also was above normal during the second growing season. Plant populations were 22,000 plants per acre, 28 inches of water was applied by furrow irrigation, and fertilizer applied included 94 lb/A 46-0-0 plus some P and K.

Under the irrigation management, some lodging was reported, especially in the taller varieties. A large portion of the lodging was attributed to root lodging with the plants leaning primarily because of heavy top weight and lack of support by wet soil in the root zone. Some neck breakage occurred in the irrigated trials, however, only a few broken heads were reported to be completely lost. Plant populations of 24,000 to 28,000 plants/A are recommended for irrigated oilseed sunflower production planted in 30 inch row spacings.

Table 1. Dryland vs. irrigated sunflower, Carrington, ( 1st. Yr.)

Avg. Yield, Irrigated

Avg. Yield, Dryland

Ratio Irrigated Dryland

3222 lb/A

1126 lb/A

2.9 to 1

*26 hybrid and variety entries.


Table 2. Sunflower oilseed yields, lb/A, Carrington (2nd Yr). *Above average rainfall.

Avg. Yield, Irrigated

Avg. Yield, Dryland

Ratio Irrigated Dryland

2216 lb/A

2356 lb/A

1 to 0.94

*Avg. of 31 hybrid entries.

Water utilization by sunflower depends on a number of factors including variety, date of planting, timing of irrigation, soil types, fertility and plant populations. Optimum utilization of water occurs if N, P and K levels are sufficiently available for high yields. All nutrient requirements of sunflower must be met for most effective use of water. Robinson, at the University of Minnesota, reported that irrigation, fertilizer and irrigation + fertilizer increased sunflower yields 35, 72 and 474%, respectively.

Water deficiency between flowering and maturity adversely influences yield more than at other times. Irrigation management becomes much more critical from early flowering until maturity. Irrigation should maintain soil moisture at 80% of field capacity at flowering stages and at 70% of field capacity at other times was optimum. Seed yields were increased 30% and oil yields 48% from irrigation 22 days after mid-flower was reported by sunflower workers in Australia.

In three years of field tests in Texas, it was reported that sunflower would yield fairly well with adequate moisture at planting time and then one additional watering at flowering time. Top yields of dryland vs. irrigation reported were 1,580 lbs. to 3,330 lb/A in year one, from 820 to 2,330 lb/A in year two and 1,740 to 2,970 lb/A in year three. Sunflower should have either rainfall or some irrigation every 14 days for maximum yield output. However, with adequate moisture at planting time, then perhaps one good watering at bloom or just prior to bloom may pay off more than where sunflower is watered several times. High costs of energy involved in irrigation may prove this type of scheduling to be economically sound.

Duane R. Berglund
NDSU Extension Agronomist



With most of the small grains seeded in the state, attention is now being directed to the planting of corn and other warm season crops. Corn acreage in ND has grown significantly in the past years and it appears that the area to be planted to corn this year may exceed that of last year. Consider the following recommendations before planting your corn crop in 2003.

When to plantThe data that is available for ND suggests that the best time to plant corn for all areas of the state is on or near May 1st. Early planting (near May 1) allows the corn crop to develop higher yield potential and be in a better state for drying down after the first killing frost in the fall. Corn can tolerate moderate frost early in the growing season as the growing point remains below the surface of the soil for several weeks after emergence. When corn planting is delayed beyond the optimum date, stay with a full season hybrid until about the 15th of May. If planting is delayed beyond the 15th of May, you should consider using an earlier maturing variety for your area. In the northern region of the state, when planting is delayed beyond the 20th of May, you should plan on planting a different crop.

What hybrid should you plant - There are literally hundreds of commercial corn hybrids to choose, though many are not adapted to ND. First, you should select a hybrid that has known adaptation to your region of the state. Review information published from corn hybrid testing trials by NDSU, information from trials planted in your area by seed companies, and experiences of neighboring farmers. Avoid growing hybrids that push the recommended maturity for your area. Later maturing hybrids tend to have higher yield potential, but you may very well end up losing money with a later maturing hybrid due to high drying costs and discounts for low test weight etc. at the elevator. Many corn farmers in 2002 experienced the "cost" of pushing the maturity of their hybrids. With so many good performing early maturing hybrids on the market, there is no need to gamble with those that are generally considered to be late for your region.

A range of adapted hybrids with specialty traits such as BT and herbicide resistance are now available in ND. If you want to grow a BT hybrid, it might pay to shop around. The tech fee or its equivalent can vary considerably from hybrid to hybrid and all BT hybrids will perform similarly against stalk borer infestations. More and more hybrids are now available which are Roundup Ready. If you are growing Roundup Ready soybeans as part of your rotation with corn, I discourage the use of Roundup Ready corn as it can facilitate the development of weeds that escape or are resistant to glyphosate and controlling Roundup resistant corn in soybeans can also be an extra cost the following season. There are some marketing restrictions on GMO corn hybrids, so it is a good idea to know your market before you grow them.

Planting corn - The optimum population density for corn is currently a topic of considerable interest. Recent data from commercial companies have shown that in many environments, densities in excess of 30,000 plants per acre are the best. Most of these data come from central Corn Belt locations where the yield potential is much higher than that of ND. There can be a considerable environment by plant population interaction. For the dryer areas of the state, high plant populations can be detrimental as they tend to use more water during vegetative growth leaving less water for the crop during the critical stages of flowering and grain filling. For regions of the state with a yield potential in excess of 100 bushels per acre, plant population between 28-30,000 plants per acre should be adequate. For dryer areas, 24-26,000 plants per acre would be more appropriate. Most research data suggest that there is little or no advantage of going from 30 inch rows to 20 inch rows. Getting good uniform establishment is critical to achieving high yields so check and adjust your planter frequently.

Given the higher yielding hybrids and the generally warmer and wetter growing seasons of the recent past in ND, including corn in your cropping system can be a viable alternative. In the extreme dry regions of North Dakota, no-till planting systems are suggested.

Joel Ransom
Extension Agronomist – Cereal Crops



In the 2003 growing season, American Crystal Sugar Company (ACSC) plan to plant 500,000 acres, Minn-Dak Farmers Cooperative (Minn-Dak) 112,000 acres, Southern Minnesota Beet Sugar Cooperative (SMBSC) 120,000 acres, and growers in western North Dakota 15,000 acres to be processed in Sidney, Montana. This gives a total of 747,000 acres of sugarbeet for Minnesota and North Dakota for 2003. As of April 28, ACSC had planted 125,000 acres (25%), Minn-Dak 68,040 (60%), SMBSC about 70,000 (58%) and growers in western North Dakota about 15,000 acres (100%).



Maximum recoverable sugar per ton and per acre correlates well with high plant populations. A plant population of 150 beets per 100 foot of 22 inch wide row at harvest is ideal for good yields of high quality sugarbeet. On average, only 64% of the total number of seeds planted will result in harvestable sugarbeet. About 26% of the seeds are lost due to non-emergence and further 10% in plants are lost from emergence to harvest. Do not ‘cut cost’ by reducing the amount of seed required to provide an optimum plant population. Remember, it is better to have excess plants that can be ‘thinned’ rather than to wish you had planted more seeds. See page 17 of your production guide for the number of seeds to be planted per acre based on seed size and spacing. Please note that a plant population of less than 150 beets per 100 foot of row (35,560 plants/A) will not only reduce yield, but it will also result in a more costly weed control program. Min-Dak farmers have harvested consistently good yields with plant populations of about 40,000 plants /A (or 168 beets per 100 foot of row).



Soil temperature in the seed placement zone must be at least 37.4EF or greater to initiate germination. Sugarbeet is a relatively cold tolerant plant that will germinate and emerge over a wide temperature range given adequate soil water. Actual seed zone temperature and duration of optimum or sub-optimum temperatures will affect emergence rate and uniformity. Growers in Southern Minnesota who planted around April 11 should have seedlings about April 25. The following table gives approximate days to emergence at different soil temperature ranges.

Soil Temperature (EF)

Days to Emergence


21 days or more


10-21 days


7-12 days


5-7 days

Mohamed Khan
Extension Sugarbeet Specialist


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