Harvest Aids for Small Grains

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

There have been a few calls about harvest aids for small grains due to poor weed control. There are only a few options available as harvest aides for wheat and feed barley (nothing labeled for malting barley). While 2,4-D and dicamba are labeled, we generally do not recommend them for this region.

Aim, Defol, and Sharpen will “burn off” the leaves and provide some drying of the stems, but they are unlikely to kill weeds. And they will not influence weed seed production. When desiccating weeds to facilitate harvest, these products work best on clear, sunny days with high temperature and high humidity. Good spray coverage is important to maximize their effectiveness.

Sharpen up to 2 fl oz

  • labeled for feed barley and wheat
  • include methylated seed oil and ammonium sulfate
  • wait until the hard-dough stage or later
  • label says to allow up to 10 days for optimum desiccation although actual time depends on environmental conditions

Aim up to 2 fl oz

  • methylated seed oil or crop oil concentrate is required
  • nitrogen fertilizer or ammonium sulfate is allowed
  • do not harvest for 7 days

Defol up to 4.8 qts

  • wheat only
  • recommended with non-ionic surfactant or crop oil
  • do not harvest for 3 days

Glyphosate

  • labeled only for wheat used for feed and feed barley (not labeled for malting barley nor wheat grown for seed)
  • apply to feed barley after the hard dough stage when grain moisture is 20% or less; apply to wheat after the hard dough stage when grain moisture is 30% or less.
  • see specific glyphosate formulations for adjuvant recommendations.
  • apply up to 1 lb ae/A
  • apply at least 7 days before harvest