Winter Wheat Growers Cautioned

Winter wheat has not been a popular crop in this area. Attempts to grow it during the early 80s brought mixed results. Yields and market prices generally were not competitive with those of spring wheat and the growing popularity with durum. Most of the yield problems came from winter injury to the seedling. Now that farming practices have changed along with improved equipment, which places seed into the previous crop stubble, winter wheat certainly proved to be a successful crop this year.

I do not want to discourage any growers from adding winter wheat to cropping sequences but I do want to alert growers of a potential pest that can devastate the crop. It is called wheat streak mosaic. This is a virus disease transmitted by the wheat curl mite.

The disease causes bright yellow streaking of the leaves which causes significant yield loss. Research at Oklahoma State University showed average yield loss of 62% for fall and 15% for spring with Wheat Streak Mosaic Virus infections. The key to prevention is to control its food source – volunteer wheat and grassy weeds. A two week window of not having a host present assures that the mite has gone through its life cycle and not found a subsequent host to feed on and transmit the virus. Insecticides are not effective in managing the vector of this disease.

Tree of the Week

To this point I have not given space to any of the coniferous trees. This was done, in part, because the list of recommended ever-green trees is not nearly as long as the list for deciduous trees.

This week’s space will be devoted to the Ponderosa Pine because I feel it gives us the best chance of survivability in this region when compared to other conifers, including Colorado Bluespruce. Its tendency to grow a strong taproot along with its fibrous-type root system likely gives it a stronger toleration to drought conditions, especially when growing in sandy soils.

Ponderosa pine is a native tree of southwestern North Dakota. Although it has drought tolerance, it prefers moist and well-drained soils. However, many of us learned last year that it does not tolerate flooding or poorly drained soils which are continuously saturated with water.

Ponderosa pine can get quite tall, upwards of 50-70 feet. When young the tree has a pyramidal form but becomes irregularly oblong and opened-crowned with age. They will gradually lose their lower limbs. Another predictable feature is needle loss. In this area I have learned the tree generally loses needles which are five or more years old. Under droughty conditions the three and four year needles are often dropped. This usually occurs in late summer and early fall.

A cultivated variety is the Rocky Mountain Ponderosa or Western Yellow Pine (Pinus ponderosa var. scopulorum). This is different from a couple of related species name Lodgepole pine and Scotch pine. The Scotch pine does not possess the drought tolerance of Ponderosa; however, Lodgepole has demonstrated drought resistance once it becomes established.

Like all other trees, Ponderosa pine does have some pest problems. For this area, the most threatening seem to be pine needle scale although the tip moth has been occasionally identified. Cyclaneusma needle cast can be a problem.