ISSUE 7   June 15, 2006


In the most recent Crop-Weather Report, 71% of the state reportedly had adequate soil moisture supplies - in line with the 5-year running average for this time of the year. On a more negative note, however, the report also indicated that 26% of the crop area had short to very short supplies of soil moisture. This is significantly greater than the 5-year average of 15%. Adequacy of soil moisture is becoming a serious concern for a large proportion of the state.

Approximate yield, water use and water use efficiency of some crops commonly grown in the northern Great Plains



Water Use, Inches

Water Use Efficiency
Yield/A/Inch H2O

Grain Corn
Sugarbeets (Sugar)
Spr. Wheat

5 tons
120 bu
400 cwt
3.2 tons
35 bu
40 bu
1500 lb.


0.2 ton
6 bu
20 cwt
0.2 ton
2.2 bu
2.7 bu
110 lb

Pinto Bean

25 bu
2200 lb
55 bu


1.7 bu
180 bu
5 bu

Source: J. W. Bauder and M. J. Ennen, NDSU Soil Science Department

Water is essential for numerous chemical reactions in the crop plant and provides structure to cells and tissues. The vast majority of the water that the crop uses, is for transpiration.

When moisture supplies are adequate, the transpiration stream brings nutrients and water from the soil via the roots to all parts of the plant, cools the plant, allows stomata to remain open and CO2 to enter the leaves. When soil moisture is limiting, stomata close, reducing the availability for CO2, increasing the temperature of the leaf tissue, reducing photosynthesis, thereby slowing plant growth (and in come cases hastening plant development). Drought stress can reduce crop yields even before the plant begins to wilt, the first visible symptom of water stress.

Crops differ significantly in their water requirements, drought tolerance and water use efficiency. Crop selection can be one way of matching water availability with crop requirement, though predicting the amount of moisture that is likely to be available in a given season is more guesswork than science.

Strictly defining the water use by a crop is difficult because water use is affected by the amount and timing that water is available. For example, a crop like corn is water use efficient (produces more dry matter per inch of water), but also has a relatively high water requirement as it has a higher yield potential than most crops. Furthermore, crops differ in how water stress might affect them. Corn, for example is very sensitive to drought during the flowering process. Wheat on the other hand, is sensitive during several weeks proceeding flowering. A crop that is stressed early in its growth cycle, may not be able to recover to the extent that it will be able to use the water that is available, even though rainfall during the latter stages of development is plentiful. Bearing in mind the difficulty of precisely defining in absolute terms the water use and water use efficiency of a crop, these two tables may be useful in categorizing crops as to their water requirements in relative terms.

Water use by selected crops in 1999-2000.


Water use (Inches)

Dry Pea






Spring Wheat




Dry bean










Source: Crop Sequence Calculator, USDA-ARS Mandan.

Crops differ in their ability to extract moisture from depths. The rank in rooting depth for crops is: safflower (about 6 ft maximum) > sunflower > corn > small grains = canola > soybeans = dry peas = dry beans (about 3 ft maximum rooting depth).

Joel Ransom
Extension Agronomist
Cereal Crops



With continued dry conditions in some regions of the state and a poor first cutting of alfalfa hay and pastures getting short of grass, many livestock producers are in need of additional forages. The time to plant foxtail millets for hay is the last two weeks of June in most years.

Foxtail millets are grown primarily for shortseason emergency hay crops. Several landraces have been developed over time and are grown in North Dakota. Seed of most hay millets, and other warm season forages maybe in short supply this season. Therefore anyone making the decision to plant for emergency forage should be checking with seed sources as soon as possible. Planting of foxtail millets can be delayed until mid-June into July. When used for emergency hay production, late planting is usually encountered. Plant into moist soil about 1 inch deep. Shallower seeding may be desirable on heavy textured soils with good moisture. Germination is fairly rapid but early seedling vigor is lacking. Foxtail millets have low seedling vigor and in general are poor competitors with weeds. A seeding rate of 15 to 30 pounds per acre is recommended. The higher rates are recommended in eastern North Dakota with the higher rainfall potential. In western North Dakota, 15 pounds is adequate on weed free fields.

Hay Millets Include The Following:

Common Foxtail millet is fine-stemmed and leafy. Seedhead is cylindrical and compact and tapers toward the tip. The lower portion is less compact than the mid-and tip portions. Seedhead varies from 5/8 to 3/4 inch in diameter and 4 to 6 inches in length with pale yellow bristles. It is one of the earliest foxtail millets, maturing in about 70 days and producing a hay crop in about 50 days.

Siberian millet has medium-sized stems and possesses some drought tolerance. The seedhead is cylindrical, 5/8 to 3/4 inch in diameter, 4 to 6 inches long, and has purple bristles. It matures in about 75 to 80 days and produces a hay crop in 55 to 60 days. Manta, a South Dakota release, is an early Siberian millet.

Hungarian millet is characterized by a small, compact, slightly lobed seedhead which is 1/2 to 5/8 inch in diameter and 4 to 6 inches long. Bristles vary in color from clear to pale yellow through purple and black. Stems are medium in size. It is reported to do better under more favorable moisture conditions. Maturity is about 70 days and a hay crop can be ready in about 55 days.

German millet has thicker stems and broader leaves. The seedhead is distinctly lobed, measuring 1 to 1 Ĺ inches in diameter and 6 to 9 inches long. Bristles are greenish to purple. It is a longer season foxtail, which takes about 90 or more days to mature and 65 to 70 days to produce a hay crop. Because of its increased stem size, it takes better management than the other foxtail millets to produce good quality hay.

Harvest millets for hay in the late boot to early bloom growth stage. Any delay after full head emergence will reduce quality. Bristles become hard as maturity approaches and may cause sore mouth, lump jaw and eye infections when fed to livestock. Hay protein content is highest when the ratio of leaves to stems is high.

Curing foxtail millet requires attention as light stands tend to sun dry rapidly after cutting, while heavy stands, especially of the German type, cure at a slower rate. If expected yield levels are greater than 1 Ĺ tons per acre, crimping will help the curing process. Potential yield of foxtail millet hay is influenced by moisture relationships. Research trial yields from NDSU Research Centers ranged from 1.5 to 4.0 tons/acre. Information on Annual Forages can be found at the following web sites:

Carrington and Streeter Research /Extension Centers

Extension web sites on Forages and Hay publications:

ProCrop Site:



Hail damage to crops occurs somewhere in the state every year. Reports have already been made last week and this week of hail in some areas of the state. When hail damage occurs on corn, soybean, dry bean and sunflower early in the growing season, replanting is possible; but deciding whether to replant is usually difficult. Total stand reduction, leaf loss, stem injury, weed control, and calendar date are factors to consider when making this decision. At this time in mid-June, itís too late to consider a replant in most cases without significant yield losses. One must always be patient and wait for plant recovery in most instances before tearing up a field and writing it off as a total loss.

Corn: The growing point remains below ground 2-3 weeks after the plant emerges (5-leaf). If the growing point is not damaged, corn will recover and perform better than replanted corn. Split the stalk down the center and inspect the growing point. If normal, it will appear white in color and firm in texture. Injured growing points will appear brown or discolored 2-3 days following the hail. Complete loss of leaves early to corn when small usually does not greatly affect grain or silage yields. Corn in the early silking and tasseling stage when damaged by hail can result in severe yield losses.

Soybean and Dry Bean: The growing points of beans are located in the top of the plant and in leaf axis. Growing points of beans are easily damaged by hail soon after emergence. Regrowth will not occur if hail stones cut the stem off below the cotyledonary node. If the top of the plant is damaged, regrowth can occur from one or more axillary buds. Bean stems may be bruised or broken. The damage may not be severe enough to kill the plant. However, the plant may lodge later as the callus tissue is weak and cannot support the pod weight. Reduction in soybean stands to four plants per linear foot of row (30" row spacings) can still produce fair yields. For dry beans one can get down to two plants per foot of row and still get fair yields.

Sunflower: Sunflower may be more tolerant than beans, but the degree of hail tolerance depends on the intensity of the hailstorm and the stage of growth. Sunflower is least tolerant during the seedling and budding stages, and most tolerant after flowering. Hail damage may be direct or indirect. Direct damage results from stand reduction, loss of recoverable heads because of severely bruised or broken stems, and head shatter at later stages. Indirect damage results from defoliation and disease infestation to injured plant tissue.

Research conducted on simulated hail losses in sunflower indicated that a one-to-one relationship does not exist between stand reduction and yield loss. A 50% stand reduction resulted in only a 28% yield reduction. Defoliation of sunflower by hail was reported to be most damaging during the bud stage. Defoliation of 80% at the bud stage resulted in yield reduction of 53%. Whereas 80% defoliation at the 50% mature stage resulted in only a 12% yield loss.

Canola: Plantings in seedling stages can have stands reduced by Ĺ and still produce acceptable yields. An average stand of 11-12 plants/ft2 can be reduced to 4/ft2 before yield losses exceed 10 percent. Prior to bolting and flower development, canola can withstand hail without much economic loss. Canola with leaves that are torn and shredded suffer only partial loss, while leaves bruised on the main vein or torn and broken will be lost. Leaf area destroyed will result in seed yield loss. Seed yield losses in canola is approximately 25 percent of leaf area lost. If leaf defoliation is 50 percent, then yield loss would be approximately 12.5 percent.

Canola plants injured in late bolting or early flowering stages seldom die. The well developed root systems and ability to rebranch and develop secondary flower clusters help the plants recover. When buds or flowers are destroyed, the canola recovers rapidly by development of flowers which normally would have aborted. New branches also develop from growth buds lower down on the plant. Seed yield loss will depend on both percent leaves and branches lost. For example, if canola has 60 percent lost branches 7 days into flowering, seed yield loss is estimated at 18 percent, whereas 21 days into flowering, yield loss would be an estimated 60 percent. If hail strikes late, such as during pod filling or ripening, plant recovery is not possible. The time needed to develop new growth, flowers and mature is limited before a killing frost. Canola seed yield loss if injury occurs at the ripening stage depends directly on the loss of branches, individual pods and seeds knocked out of pods. Severe hail losses have occurred in canola swaths.

Duane R. Berglund
NDSU Extension Agronomist



Alfalfa harvest should begin this week in some areas even though buds are just beginning to develop. We harvested our first field on May 30 when the alfalfa measured 26 to 28 inches in height and the maturity stage was very early bud.

The prime objective in determining when to harvest is to obtain prime hay in the bale. This is especially true for cash hay producers and dairy operations where prime hay means greater net returns for the alfalfa crop, but it can be important for beef cow producers also as a source of high-quality high-protein hay to be used in rations with other low-quality hays like mature grasses or slough hay.

Many factors enter into the decision of when to harvest alfalfa such as environmental conditions, other field work, insect infestations, etc. But what factor(s) should be used to determine when to harvest if these are not determining factors?

Plant maturity or calendar date has been used extensively to determine the optimum time to harvest, but I believe plant height is more important in determining when to harvest than plant maturity and especially calendar date. The growing season changes the optimum time to take the first cutting. If the spring is late and the temperature average to below average, high-quality hay can be obtained with harvesting alfalfa at a later maturity stage, late-bud to early bloom, like in 2005. But if the spring is early and above-normal temperature, the optimum harvest stage will be earlier like in 2002 when first harvest was taken on May 24.

Plant height is a best indicator of when to take the first harvest (Table 1). Note that the relative feed value (RFV) decreased from 220 to 149 as the plant height increased from 16 to 35 inches when all samples were taken at the early bud stage. A similar effect was seen at the early flower stage. Also note that the loss in RFV was much less when the maturity stage increased from early bud to early flower within a given height.

We have found that harvest should begin whenever the alfalfa reaches from 26 to 28 inches in height, regardless of the maturity stage, if prime hay in the bale is desired. The estimated RFV in Table 1 is for alfalfa standing in the field. Therefore, harvest must begin when the estimated RFV is from 175 to 180 to allow for harvesting losses.

Table 1 also illustrates why harvest at early flower during the first harvest would be recommended when growth is less than 20 inches in height. Therefore, under drought when growth is reduced, waiting for a more advanced maturity stage to allow increased production would be a wise management stragity. But waiting for increased yield when growth is good leads to poor quality hay. By harvesting early under good growing conditions, there is increased opportunity for an additional harvest that more than offsets the yield loss in the first harvest by harvesting early.

Fields generally have varying maturity and height. Frequently hilltops have less growth and are more advanced in maturity than lower wetter areas of the field. Base your decision when to harvest on the valleys realizing that the short growth and more advanced maturity on the hilltops will not affect the quality extensively.

Second and third harvests usually are shorter than the first harvest. Therefore, the maturity stage at harvest will be more advanced than the first harvest. We have found that under a four-cut system, the maturity at harvest generally is late but to 10% bloom in the second harvest and 25 to 30% bloom in the third harvest. Again, this may vary depending on the year and moisture level so itís best to use height to help decide when to harvest.

In summary, plant height is the best indicator to use in determining when to harvest, especially in the first harvest, but also in later harvests.

Table 1. Estimated RFV by plant height at two maturity stages.

Plant height

Early bud

Early flower





Dwain Meyer
Plant Science

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