Posts Tagged ‘Cochiobolis’

July 26, 2010, Field Notes, brown spot, sprangletop, glyphosate injury

July 28, 2010

Brown Spot Disease in a Rice Field. Photo by K. Fontenot

Brown spot disease of rice is often associated with nutrient problems.  In this field the pattern of the disease reflects that because the disease is most severe where in the process of land leveling more top soil was removed.

Glyphosate Injury to Rice Panicles

In other images of glyphosate injury posted on this blog there has been more distortion of the grains and the flag leaf.  In this field the drift event occurred late when panicle development was fairly advanced.  The primary symptoms visible here are sterile grains.  Little grain or panicle distortion is evident, but the effect is dramatic.

Severe infestation of Sprangletop in a rice field. Photo by N. Hummel

A combination of factors including possible herbicide resistance led to this severe infestation of a rice field by Tighthead (Amazon) Sprangletop.  Sprangletop is one of the most difficult to control grass weeds in rice production.

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