Insect control and disease management strategies for wet spring weather and delayed planting.

Wet Spring Worsens Insects and Disease

June 2015

Moth flights and egg laying throughout the South remind us of the potential for pests to take a bite out of yields. Seedlings may be especially vulnerable to insects and disease this year. A wet spring, delayed planting and storm damage are stressors that make plants more vulnerable to insect feeding and foliar diseases. Fortunately, you can help protect crops so they get a strong start. Read on for news about disease and insect control strategies and why the Weed Science Society of America is setting the record straight on “superweeds.”

In this issue:  In the Field

Pest challenges are always evolving, including the potential for insects and diseases to develop resistance. Your scout-and-spray program can be enhanced by rotating modes of action, and using DuPont Crop Protection products with multiple modes of action and residual control.

Residual Insect Control Gives Application Flexibility

This year, cool weather may give insects an advantage and multiple pests may be attacking crops at the same time. A worm complex of multiple insect species can create cumulative crop damage and rapid worm feeding can occur after eggs hatch.

One of the best control strategies for preventing losses due to the worm complex is simple: Don't wait for worms. Instead, scout for moth flights with pheromone traps and look for egg masses on leaves to plan timely treatment before feeding begins. Recommended treatment thresholds from university extension can help decide when to apply control measures.

  • Many of the same insect pests attack soybeans, cotton and corn at crucial grain and pod fill stages. Moths can travel long distances.
  • Insect pests are evolving resistance to Bt crop traits and conventional insecticides.
  • Crop stage is crucial for effective treatment. Pest scouting calendars are available online from DuPont Pioneer for corn and soybeans.

Two-Mode Disease Control Protects Yield and Fights Resistance

DuPont™ Aproach® Prima fungicide helps protect genetic potential for yield and grain quality with a unique combination of preventive and curative properties for rapid foliar uptake and systemic redistribution throughout the plant to control disease, even in dense leaf canopies. Aproach® Prima is labeled for use on corn, soybeans and wheat.

Diseases controlled on soybeans include frogeye leaf spot (including strobilurin-resistant disease), aerial web blight, Cercospora blight, rusts, mildews, and pod and stem blights. Apply to soybeans starting at R3 with scout-and-spray follow-up application if needed. (Apply no more than two sequential applications of a picoxystrobin-containing product before switching to a fungicide with a different mode of action. Minimum retreatment interval is 7 days for corn and 14 days for soybeans and wheat. Do not exceed 6.8 fluid ounces per acre in a single application per crop or more than 13.6 fluid ounces per acre total to soybeans.)

Corn diseases controlled by Aproach® Prima include gray leaf spot, northern corn leaf blight, southern rust and common rust. See the recent Southeast Farm Press article about how fungicides improved Georgia corn yields by 70 to 80 bushels per acre in 2014.

Aproach® Prima benefits:

  • Two modes of action with a premix of the strobilurin in Aproach® plus a premier triazole, cyproconazole.
  • Preventive and curative control with residual and systemic activity throughout the plant.
  • Rapid movement into the plant to quickly stop yield-robbing disease.
  • Systemic movement within the crop canopy for total plant protection, even deep under the leaf canopy.
  • Excellent residual activity for ongoing disease protection.
  • Easy use and tank-mix compatibility to save time and allow use with herbicides and insecticides.
  • Excellent crop safety.

Check out a recent Delta Farm Press article and video describing how Aproach® Prima controls soybean diseases, including resistant frogeye leafspot.

Visit the Southern Seed to Harvest Resource Center for product videos, plot tours, case studies, information and ideas are available from DuPont online.

Q: What is a “superweed”?

A: From The Wall Street Journal to the Oxford Dictionary, the term “superweed” has been gaining traction in the media, among activist groups and in the general public. Of course, farmers and crop consultants have been managing tough weeds and herbicide-resistant weeds for many years, but emergence of the term superweed has brought with it some misconceptions about how production agriculture pros manage weed control. For example, a commonly repeated false statement is that herbicide-resistant weeds are the result of genes being transferred from genetically modified crops to wild plant populations. In fact, scientists and crop consultants know weeds evolve resistance through overuse of single herbicide mode of action on the same field year after year, using off-label rates that don't fully control weeds, and letting weeds get too large for effective control before they produce seed.

The Weed Science Society of America recently released Dispelling Common Misconceptions About Superweeds. It's useful information for when you get questions about resistant weeds and herbicide use.

Always read and follow all label directions and precautions for use.

DuPont Aproach® and Aproach® Prima are not available in all states. See your local DuPont sales representative or retailer for details on availability.

Lorsban® (Dow).