June 22, 2007

Excessive rain and floods, hail, tornadoes, and other calamities sometimes force us to replant crops.

After disaster strikes, replanting a grain crop may be nearly impossible due to herbicide carryover or the late planting date. As a result, annual emergency forage crops might be your only choice. Before selecting any crop to replant as forage, be sure to check the label of any herbicides used previously. Many herbicides have restrictions and limitations on grazing or feeding forage grown after they were applied.

In addition, unless only glyphosate was used, other herbicides can injure forages. Many herbicides for corn and milo will injure pearl millet and foxtail millet, but sudangrass, forage sorghum, and sorghum-sudan hybrids will tolerate moderate levels of atrazine; and safened seed can be used if Dual or Bicep-like herbicides have been applied. These sorghums also tolerate most herbicides labeled for use with grain sorghum.

Also, short-season corn can be planted for silage or bin-run corn can be drilled in for late season pasture, especially if corn herbicides eliminate other possibilities.

Soybean herbicides other than glyphosate cause even bigger problems for replanting to forages. All summer grasses are sensitive to most soybean herbicides. Sunflowers for silage and soybeans for hay or silage are among the few alternatives compatible with soybean herbicide carryover.Nobody likes to replant, but if you must, select a forage that is compatible with your herbicides and livestock.

Bruce Anderson
Extension Forage Specialist