By Dave Nanda, Director of Genetics and Technology Seed Consultants, Inc.
Drought not only affected our crops this year, it has the potential of affecting crops in 2013 also. In this space we have already discussed that all of the nitrogen, potash and phosphate may not have been used if your yields were low. This could be a potential cost saving by reducing the amount of certain fertilizers needed. However, on the negative side, there is a potential danger of herbicide carryover that could hurt your crops if effective measures are not taken. If you did not get sufficient rains to wash down the residual herbicides, these could hurt wheat, soybeans and corn depending on the herbicides, time of application and amount used. Purdue Extension Weed Scientists, Bill Johnson and Travis Legleiter have given the following cautions and potential solutions:
• Watch out for atrazine carryover damage to wheat.
• If you applied a fomesafen product to soybeans this summer and did not get sufficient rains following application, there is a potential of injury to wheat.
• If you don’t get significant moisture this fall and winter, there is a potential risk from atrazine and HPPD inhibitors carryover into soybeans in soils with high pH or clay soils.
• Imidazolinone herbicides carryover could hurt corn which is planted very early. It may be better not to get in a hurry in planting corn next spring.
• Consider getting a bioassay analysis by planting sensitive crop seeds on farms where you expect herbicide carryover problem.
• Have a scout take soil samples of suspected fields and get them analyzed. Even though these tests are not cheap, they may be less expensive in the long run.