Wednesday, August 17, 2011

Early winter wheat planting considerations

Hopefully, you are wrapping up harvest in the next few days! All reports I have heard have been very positive, so no one is complaining about finishing up late. Yet, with the excellent moisture conditions and the cool night time temperatures, it looks like we will be seeing significant amounts of early seeding in the area.
Early seeding likely faces two challenges this fall. One is aphids and the second is fall infections of stripe rust.

On the topic of aphids, if you are seeding early, prior to October 15th, an insecticidal seed treatment is your best management tool to prevent aphids transmitting Barley Yellow Dwarf Virus (BYDV). Especially in areas adjacent to irrigated fields of corn, last fall, we saw a migration of aphids to early seeded wheat. Fall infections of BYDV can seriously impact yields. Typically, delaying seeding until later in the fall will reduce the level of infection due to a shorter window of opportunity for aphids to infect the plants. Fall aerial applications of insecticides can be effective, but it is challenging to get the timing right. Always scout your fields before making crop management decisions.

The second challenge that we face this fall is one we have been talking about since the field days in June – the potential for fall infections of stripe rust. Given the high inoculum levels we experienced this past growing season, and the below average temperatures that have continued most of the summer, it is very likely we will again see fall infections of stripe rust in our area.
In our drier parts of the area, the benefits of early seeding still outweigh delaying. The only remaining option is to look at variety selection. The following list, provided by the Mike Flowers and the OSU Cereal Breeding Program, is based on their many observations across the state this past season. These varieties are the most susceptible to stripe rust and should be avoided if possible:
Soft White Winter
Hard Red Winter
AP Badger
AP Paladin
AP Legacy
Tubbs 06
UICF Grace

WB Rimrock

WB Tucson


Fall application of fungicides for stripe rust control are not recommended as fall/winter environmental conditions may provide some levels of control. It will be important to scout fields, regardless of variety, in late February or early March, depending on growing conditions and weather. If stripe rust is found an application of fungicide is recommended, and can possibility be tank mixed with spring herbicide applications.

Thanks to Mike Flowers, OSU Cereal Specialist, for information he provided for this article.

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