High Plains/West Texas
Numerous questions have arisen since July 7 on later planted grain sorghum (June and later) especially in the High Plains about poor growth and stagnation. At earlier times of the year these can be issues in South & Central Texas as well, especially the potential herbicide and iron considerations. Here are several questions including:
- What causes the purple color in grain sorghum?
- Is the yellowing iron (Fe) deficiency or something more?
- Is Atrazine or Dual (s-metolochlor) to blame for poor sorghum growth?
- Why is the sorghum so stunted and why is there little rooting?
- Some sorghum appears to be dying.
- If my sorghum is struggling, should I replant, applier foliar nutrient treatments, or wait it out?
I wrote about these above questions and discuss these one at a time in the July 10 edition of “FOCUS on South Plains Agriculture” newsletter, pages 11-18, at http://lubbock.tamu.edu/focus-newsletter/ .
I did not mention glyphosate (Roundup) in the above update at the time of writing though there are some instances where we think some drift might have occurred. Also, there are numerous fields (Armstrong and Floyd Cos., for example) where we repeatedly find that grain sorghum that had some protection either from wheat stubble, adjacent irrigated corn (grain sorghum is on the corners), a fencerow, a strip of weeds along the edge of the field, etc. –this sorghum looks much better than other sorghum across the field. This protection could have reduced the level of contact with drifting chemical or perhaps minimized blowing dust which is purported to cause static electricity damage to seedling crops (there is no verification in the literature that this is indeed a causal factor, rather ‘environmental damage’ is probably a better fit which would include the potential abrasion of dust with plant tissue).
An overarching concern for some producers is the lack of root development from the base of the crowns as these are needed to sustain the crop beyond the seedling radicle (the initial root that emerges from the seed). I, and colleagues, have been hard pressed to narrow down an explanation. One naturally would assume that lack of root growth is a combination of herbicide injury (drift or from within the soil) and water-logged soils, but we are having trouble finding a common thread to explain field observations.
