Posted 20 July 2009. PMN Crop News.
Scouting Season: Protect Sunflowers from Pests, Diseases
Source: Dow AgroSciences Press Release. www.dowagro.com
Indianapolis, Indiana (July 15, 2009)--Left untreated, pests, diseases and weeds can be devastating in sunflower fields. However, diligent crop scouting can prevent disaster and contribute to a healthy crop.
“The best way to protect your crop is to actively scout. If you are out there looking for the problems, a solution can be found and put into action in a timely matter,” says Doug Heatwole, Mycogen Seeds customer agronomist. Heatwole suggests the following basic tips for successful sunflower scouting:
• Have a plan of attack — Identify what pests are active during the crop growth cycle and scout your fields every seven to 10 days.
• Do your homework — Use tools and resources from Extension and other reference publications, and do some extra research in order to understand what pests and diseases look like; saving photos to a cell phone or portable device can allow for quick identification as can various field scouting guides.
• Get out of the truck — Survey all representative areas of a field and use scouting guides from a trusted source to develop more specific procedures. There is no substitute for actually walking the fields.
• Keep thorough records — Take notes, pictures and samples when you are scouting. Digital photos are easy to e-mail to an agronomist if you need help identifying a pest or a plant disease, but actual samples is best when they are preserved correctly.
“Scouting is the No. 1 best prevention of pest infestation,” Heatwole says. “By first identifying the pests that are potential threats and then diligently scouting for them, a disaster can be avoided.”
Many sunflower pests overwinter in fields, posing a threat from the minute sunflower planting begins. Watch out for the longhorned beetle and the stem weevil; both occur at the same time.
The longhorned beetle is a pest to watch for as the season progresses. It bores into the stalk, forming a cavity in the soft area of the stalk. There, the larvae feed and then tunnel down to the stem in a sunflower plant. A capsule is drilled out where the beetle cocoons and pupates, and the next generation of the longhorned beetle is formed. The stalk of the plant then falls over.
The stem weevil is a small, gray-brown insect with white dots on its back. It tunnels through the pith of the stalk and causes the stalk to break. Damage from the stem weevil is particularly dangerous in conditions of high winds or drought.
Later in the season, two potentially damaging sunflower diseases to watch for are red rust and sclerotinia. Clusters of yellow or orange spots on leaf surfaces are a warning sign of rust. If untreated, yield, oil percentage, size and kernel-to-hull ratio can be affected by rust. To identify sclerotinia, look for sudden wilting of leaves, lesions near leaf nodes and white fungus growing over the flower.
“When you see a problem, turn to your trusted agronomist for advice and options,” says Bruce Due, Mycogen Seeds customer agronomist. “Retailers, crop protection representatives and university specialists are also great resources.”
Due also recommends subscribing to the newsletter from your state university and newsletters from universities in neighboring states.
“Weather and disease trends throughout a larger region can affect crops in bordering states. It’s good to have a heads-up and be aware of any potential threats,” Due says. “Web sites with this type of information can be even timelier and allow growers to act more quickly to potential problems.”
For tough weed, insect and disease problems, the Mycogen Seeds customer agronomists and sales representatives are available to help. This experienced and knowledgeable team of agronomists can be consulted about issues on a local level and are there to provide solutions to agronomy problems. To connect with your nearest Mycogen Seeds customer agronomist, call 1-800-MYCOGEN.