Diagnosing spring drought in wheat and barley

Spring drought refers to plant water stress from insufficient rainfall or stored soil moisture occurring between tillering to maturity.

 

Wilted dying older leaves and spiky new growth.
Rat-tail head with awns caught in furled flag leaf.
Better growth in water gaining areas.
Symptoms worse where double sown.

What to look for

    Paddock

  • Large areas of stressed or dying plants with some better plants in water gaining areas.
  • Low water holding soils, such as coarse sands and gravels, very shallow soil over rock or impermeable layer are more affected.
  • Heavy clays that retain moisture near the soil surface after light rainfall where it is more likely to evaporate.
  • Areas within the root zone of trees.
  • Can be seen in double sown areas or areas of vigorous plants.

    Plant

  • Shorter plants.
  • Older leaf wilting and becoming dull.
  • Young leaves furled and spiky.
  • Oldest leaf tipping and death that progresses to other leaves.
  • Rat-tailed or sterile heads.
  • Shrivelled grain.

What else could it be

Condition Similarities Differences
Soil acidity, boron toxicity, hostile clay loam to clay subsoil and waterlogging
Early plant death and shrivelled grain Causes can be determined by rainfall records, soil type and location
Diagnosing stem and head frost damage in cereals White or rat-tailed head, shrivelled grain Frost plants are not water stressed, and are more landscape dependent
Diagnosing copper deficiency in wheat White or rat-tailed head, shrivelled grain Youngest leaves are affected and maturity is delayed with copper deficiency
Diagnosing molybdenum deficiency in cereals Water stressed plants with white or rat-tailed head, shrivelled grain Molybdenum deficient plants symptoms are more scattered and maturity is delayed

How can it be monitored?

  • Unless the problem is obviously due to drought, dig a hole and examine the soil profile for: Soil pH.
  • Presence of restricting layers.
  • Soil texture.
Page last updated: Monday, 22 June 2015 - 4:46pm