ISSUE #528

528 - Fungicide Use and Plant Health Strategies


Cercospora control is more easily achieved today than at anytime in the past because of the excellent selection of fungicides available. At least 6 products provide very good to excellent Cercospora control; however, not all of them provide equal plant health benefits. Plant health benefits are much too significant to disregard.

What Is This So Called "Plant Health Effect"?

A Brooms Barn Research Center team of scientists has extensively studied the non-disease control benefits of fungicides on sugarbeet for about 10 years in the UK. They pointed out its critical to remember about 35% of the final yield of sugarbeet comes in late August, September and early October. Maintaining productivity during this period is critical to achieving maximum yield potential. They determined plant health benefits include:

  • Reduced canopy senescence
  • Increased leaf chlorophyll content
  • Improved photosynthetic activity
  • Increased solar radiation interception and utilization

Brooms Barn scientists also claim "These products provide a clear yield benefit that goes beyond any effect related to disease control". British Sugar Beet Review Vol. 72, No. 2, Page 44.

Red River Valley Research Results

Dr. Larry Smith has extensively evaluated the non-disease plant health benefits of fungicides for 6 years in 12 experiments. He has concluded that

  • Greatest benefit is realized when Headline is applied 30-40 days before harvest
  • Leaf senescence is reduced and delayed
  • Photosynthesis is improved
  • Crop canopy is much more frost tolerant
  • $50-150 or more revenue increase is achieved


American Crystal Sugar Company Agriculturists Observed Plant Health Benefits Are:

  • Less leaf senescence
  • A greener canopy
  • Improved frost tolerance
  • More rapid recovery after frost damage with a quicker resumption of harvest
  • Better yield and revenue


Zone Fertility Managed Acres Top 40% in 2009

Use of zone soil sampling has increased from less than 9% in 2003 to over 40% in 2009, Figure 2. Zone soil sampling followed by variable rate fertilization consistently increases on-farm profit. As little as 15 lbs. of difference between zones justifies variable rate fertilizer application.

"Satellite imagery and zone mapping is your road map to most efficient fertilizer N use and increased profitability".


The ACSC Agriculture Department strongly recommends Headline application on every field 30-40 days before harvest. Four year grower records show $67 revenue/acre increase.

Zone Management $$

Zone Fertility Management has given $52/acre improved revenue from 2006-2008.

Causes of Nitrogen Variability

  • Excessive rainfall causes leaching
  • Excessive rainfall causes denitrification
  • Soil temperature effects mineralization
  • Soil type
  • Organic matter level
  • Previous crop yield
  • Past cultural practices and crop rotation
  • Prevented planting