ISSUE #495

495 - Root Maggot Forecast Higher In 2007

3-8-07

The sugarbeet root maggot populations declined throughout the Red River Valley during the wet growing seasons from 1993 – 2005. Populations dipped to the lowest levels in 30 years except in Walsh and Pembina counties. Growers, Agriculturists and even some entomologists tended to relax their vigilance and control measure recommendations. The much drier and warmer conditions in 2006 saw a very definite surge in fly numbers and root maggot survival throughout the Red River Valley. Dr. Mark Boetel, NDSU Sugarbeet Entomologist has forecast much higher root maggot populations for 2007, see figure 1. Not only will populations be higher but they will require tougher control measures in 2007. Don’t let sugarbeet root maggots (SBRM) reduce stand, yield, and revenue this year.

495.1

Concerns for 2007

  • Higher SBRM populations
  • Expansion of threatened acreage
  • Too many acres treated with Mustang
  • New planters without insecticide boxes
  • Drier soil conditions enhance survival
  • Incomplete SBRM control with some 2006 management strategies

SBRM Control strategies for 2007

  • Review the NDSU forecast for your area
  • Review 2007 control plans with your Agriculturist
  • Don’t use Mustang Max in areas expected to have moderate or severe pressure
  • Use second applications of insecticide with high SBRM populations
  • Consider POST insecticide application especially if dry weather after planting doesn’t fully activate granules
  • In high SBRM population areas use full label rates of Counter or Lorsban
  • For moderate SBRM populations use 75 to 80% of full labeled rates
  • Greatest SBRM threat is on moderate to light textured soils

Which Insecticide Controls SBRM Best?

  • Counter treatments gave the greatest recoverable sugar per acre
  • Counter treatments gave the greatest increase in Revenue/Acre versus check treatment
  • Untreated controls lost about 3,500 lbs. recoverable sugar per acre

495.2

Insecticide Use and Stand Loss

  • Calibrate applicator units to ensure correct rates are used
  • Banders and spoon attachments reduce risk of stand loss
  • Greatest stand loss risk is with high rates, MIF application and no calibration

Information and Assistance is Available

  • Your Agriculturist
  • University specialists
  • Research and Extension reports
  • Pocket Production Guide
  • May and June weekly fly counts available from Agriculturists and on DTN/Internet

Warning

Mustang Max will give inadequate SBRM control use another product in areas where SBRM populations are increasing.

Test Stand Clinics

Don’t miss the opportunity to fine tune your planter at one of the 18 locations in the RRV starting in early March.