|Ohio Farm News
By Steve Bartels
March came in pretty much like a lamb and it sure went out like one. Warmer weather has favored the growth of wheat and other grass crops. Wheat growth stage can vary a great deal from field to field depending on planting date, soils, moisture supply and fertility. We canít depend on the calendar or even the plant height to estimate growth stage when deciding to make herbicide applications.
Some herbicides are labeled to be applied before the stem begins to elongate. Most of us know that as jointing. If these herbicides are applied too late they will injure the crop. We have seen Banvel and some 2,4-D products cause greatly reduced yields. Be sure to check the label of each product before you apply to determine the correct growth stage for that herbicide.
You need to learn to identify the growth stages of wheat to help you better manage your crop. The Feekes growth stage scale is the commonly used system. As an example, stem elongation, the beginning of jointing, is growth stage 6. Stage 6 is called the first node of stem visible stage. Not only are herbicide decisions made by the Feekes Scale, but also all spring topdressing of nitrogen should be applied by stage 6 so the wheat can take full advantage of the nitrogen.
You canít decide if the wheat is in stage 6 without digging up a few plants and looking at their largest tillers. Take a large tiller and strip down the several layers of bottom leaves and leaf sheaths to look at the lower stem. The plant is in growth stage 6 when you can find the first node on the lower stem above the crown of the plant. As with most things in nature, itís not always simple. The first node may be from a half inch to several inches above the crown. Here in Butler County, growth stage 6 normally occurs around mid-April.
You can find the Feekes Growth Scale in several publications on Ohioline. Go to http://ohioline.osu.edu
Ohio State University Extension has published the 14th edition of the Ohio Agronomy Guide this past winter. On page 84 of this publication is an excellent chart of the Feekes Scale with the herbicides, which are used and, when they can be used, superimposed on the scale. This is an excellent reference.
This farm news was published in the April 12, 2006 issue of Farm World.