GREEN AND GROWING
D. Bruce Bosley
Extension Agent/Cropping Systems
Colorado State University Cooperative Extension

Nearly all the 2004/2005 northeast Colorado winter wheat crop was impacted by wheat diseases. Drought and heat stress also factored into the yield reduction experienced by many irrigated and most dryland fields. Dryland producers have few remedies for reducing drought risk; however, there are steps that wheat producers can do to reduce disease risks for the 2005/2006 crop. Some of these remedies can be initiated now in the late summer.

Planting resistant varieties can be an effective, economical, and environmentally friendly method of disease control. Planting several different varieties with different strengths and weaknesses is a good disease management and risk management strategy. It reduces the risk that any particular disease or weather event, such as freeze or heat stress will cause catastrophic losses. Consider stripe rust resistance in selecting varieties for irrigated and high yield wheat situations- Hatcher and Jagalene are both high yielding and moderately resistant/resistant to stripe rust if rust races don’t change in the next year and become virulent to these varieties.

Control volunteer wheat to eliminate the “green bridge” that allows pests to survive the period between wheat crops. Volunteer wheat serves as a reservoir for wheat streak mosaic, High plains mosaic, barley yellow dwarf, and leaf rust. It also harbors Russian wheat aphids and other wheat insect and arthropod pests. The objective is to break the green bridge before the new crop emerges. Therefore, volunteer should be eradicated at least 2 weeks before planting to ensure a thorough kill. Field border treatments reduce the spread of insects such as grasshoppers, aphids and greenbugs, and depending on the insecticide reduce wheat curl mites.

Early planting is also a risk factor for several diseases including wheat streak mosaic, High plains mosaic, and barley yellow dwarf. Avoid planting wheat in Northeast Colorado before September 10, and hopefully adjacent crops and grass areas will not remain green past the end of September.

Please contact me, Bruce Bosley on these or other topics at (970)522-3200 extension 285.