Some crops are more sensitive to herbicide carry-over than others. Sunflowers can be negatively affected by herbicide residues. Visual damage can vary from mild to severe symptoms, but yield potential and quality can be affected greatly. The following recommendations are from the Guide to Field Crop Protection 2009. For more information and to verify risk, please talk to the marketing company listed with the herbicide in question. Breakdown of herbicides may be slowed or delayed by drought, excessive cold and/or soil pH; increasing the potential for injury to rotational crops. When speaking to your local agronomist, company representative, or the manufacturer call-in centre, have the following information available:
Herbicide (and rate) applied, number of applications
Crop applied on and approximate staging
Date (approximate) of application, environmental conditions for growing season
Field soil type and pH
Management of crop residues (incorporated, removed, burned, zero tillage)
Company contacts: Arysta LifeSciences: 204-981-9303; BASF: 877-371-2273; Bayer Crop Sciences: 888-283-6847; Dow AgroSciences: 800-667-3852; DuPont: 800-667-3925; Nufarm Agriculture: 800-868-5444; Syngenta: 877-964-3682; UAP: 800-561-5444.