Plant Pathology Infobytes

April 13, 1998
Decision Time for Cotton Seedling Disease Management

Although the impact of cotton diseases varies from year to year, Mississippi producers rarely experience a season when attention to disease management planning doesn't pay off. Producers who plan ahead can usually avoid major problems from seedling disease, and other disease or nematode pests.

Cotton disease and nematode management is 99% preplant planning. Setting up a good disease defense makes good sense not only in terms of crop yield and quality protection but will also mean a better chance of harvesting on schedule.

A good way to begin the 1998 season is to plan your seedling disease management program. While the damaging effects of seedling diseases caused by Rhizoctonia solani, Pythium spp., Fusarium spp., and Thielaviopsis basicola can be reduced to some degree by cultural practices, producers still have to rely on fungicide seed treatments, planter box fungicides, and in-furrow fungicide granules or sprays as the main line defense against these seedling disease pests.

Take time to evaluate production problems from seedling disease in past seasons. Based on a field-by-field analysis, where are problems most likely to occur in a wet, cool spring?

In seedling disease "hot spot" fields, and when planting early, the expense of more expensive in-furrow treatments can be justified as insurance in helping obtain an acceptable stand of relatively disease-free seedlings. But, later in the planting season, consider the use of less expensive planter box fungicides, which will provide adequate protection when conditions are less conducive to seedling disease development.

What are some of the factors to consider in making a decision on the type of fungicide treatment? Research has demonstrated that in- furrow fungicide spray or granule treatments generally provide better seedling disease protection when planting:

  • In fields with a history of seedling disease
  • In April or early May
  • When soil temperatures are below 65 deg. F.
  • In light, sandy textured soils where Rhizoctonia sore-shin problems can be expected
  • When using in-furrow systemic fungicides
  • Planting seeds of lower vigor
  • Re-plant fields

In-Furrow Granules

  • Ridomil 5G (for broader spectrum disease control combine with Terraclor 10G)
  • Ridomil Gold GR (for broader spectrum disease control combine with Terraclor 10G)
  • Ridomil PC 11G
  • Ridomil Gold PC
  • Terraclor 10G (for broader spectrum disease control combine with Ridomil 5G)
  • Terraclor Super X 12.5G
  • Terraclor Super X 18.8G
  • Terraclor 6.5 % plus Di-Syston 6.5%
  • Terraclor Super X with Di-Syston
  • Terraclor 6.5 with Thimet 6.5%

In-Furrow Sprays

  • Demosan 65W
  • Ridomil 2E (for broader spectrum disease control, mix with Terraclor 2E)
  • Ridomil 50W (for broader spectrum disease control, mix with Terraclor 2E)
  • Ridomil Gold EC (for broader spectrum disease control, mix with Terraclor 2E)
  • Ridomil Gold WSP Accu-Pak (for broader spectrum disease control, mix with Terraclor 2E)
  • Ridomil PC Liquid Twin-Pak
  • Terraclor Super X EC
  • Terraclor Super X plus Di-Syston EC
  • Terraclor 2E

Planter Box Fungicides

  • Allegiance (for Pythium protection; provides no control of Rhizoctonia seedling disease)
  • Delta Coat AD
  • Demosan 65W Hopper Box Treatment (primarily for Rhizoctonia seedling disease control)
  • Demosan Flowable (primarily for Rhizoctonia seedling disease control)
  • Kodiak HB Biological
  • System 3

Refer to product labels for recommended rates per acre and other appropriate application instructions.


Written by the late Dr. Frank Killebrew

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