Assessing Winter Grain Stands in Early Spring

By Ellen Mallory, University of Maine Extension Sustainable Agriculture Specialist

Once the snow melts and temperatures rise, it’s time to look at how well our fall-seeded grains, like winter wheat, triticale and spelt, survived the winter. Winter grains have many advantages over their spring counterparts (less weed pressure, higher yield potential, lessened spring workload), but over-wintering is not always assured. Late fall planting, poorly adapted varieties, and adverse weather conditions can all contribute to poor stands in the spring. Winter weather conditions that are challenging for winter grains include intermittent snow cover and periods of surface melting followed by icing. Low lying areas of fields are likely to be most affected.

When assessing winter survival in the spring at greenup, first get a sense of how patchy the field looks, and then focus initially on the worst-looking areas. If those areas turn out to be OK, the rest of your field should also be fine. As you scout, be aware that dried, brown leaves do not necessarily indicate that the plants are dead. Likewise, green leaves do not necessarily indicate the plants have survived. The only way to know the status of individual plants is to peel back any dead, outer leaves and examine the crown. A healthy plant should have a bright, white crown.  Once temperatures have been warm enough for new growth, they should also have new white roots.

Is the stand worth keeping?

Having a good stand in the spring is key to a productive winter grain crop. Counting plants per square foot at greenup can help you decide if the stand is worth keeping. To do this, take a foot-long ruler and lay it along an average looking row in the field, count the number of healthy plants in that one-foot length, and write it down. Be sure to count individual plants, not tillers. You may need to dig up the plants to count them accurately. Do this in several areas that are representative of the field or the patches you are examining. Calculate the average of these numbers, then multiple that number by 12 and divide by your row width. This will give you the average number of plants per foot.  For example, 14 (plants per 1- foot length) x 12 ÷ 7 (inch rows) = 24 plants per square foot. Plant stands with 20-30 plants per square foot are considered optimum. Stands with 12-15 should be adequate, especially if nitrogen can be applied to stimulate tillering (see below).  If the number of plants per square foot is less than 8-12, consider replanting the field to another crop.

If you determine the crop is worth keeping, but are concerned about bare patches, consider underseeding clover to compete with weeds. Do not inter-seed spring wheat into winter wheat as they will ripen at two different times.

Is additional nitrogen needed, and when?

For winter grains, it is recommended to delay the application of a portion of nitrogen until spring to avoid over winter loss. At what point in the spring you make this topdress nitrogen application will depend on your tiller numbers at greenup. If tiller numbers are low, there’s a 2-3 week interval in early spring when N applications will stimulate tillering and increase the number of heads per square foot. However, early spring nitrogen applications are susceptible to leaching losses if spring rainfall is heavy. Therefore, if tiller counts are good, it’s better to topdress a bit later in the spring for the most efficient use of nitrogen by the crop.

To decide if early nitrogen topdressing is necessary, count the number of tillers per square foot. Use the same counting method as above, but count all main stems and tillers with three or more leaves in the 1-foot length of row. Calculate tillers per square foot also as above. If tiller numbers are less than 70 tillers per square foot, consider topdressing additional nitrogen while the crop is in the early tillering stage. If tiller counts are above 70 tillers per square foot, delay your spring topdressing until just before the plants start to joint (i.e. stems elongate), which is when the plants enter their most rapid stage of growth.

For a video of how to conduct tiller counts, see Counting Tillers to Optimize Spring Nitrogen Rates & Timing by Randy Weisz at North Carolina State University.