Midwest Vegetable Guide - 2022 - 258

Root Crops - Diseases
Reason 500SC (4.13) (fenamidone) Beet, Carrot, Celeriac,
Horseradish, Parsnip, Radish, Rutabaga, Turnip | 8.2 fl. oz.
per acre. Pythium damping-off only. REI: 12-hour. PHI: 14day.
FRAC 11.
Uniform (L) (mefenoxam, azoxystrobin) Beet, Celeriac,
Horseradish, Parsnip, Radish, Rutabaga, Turnip | 0.34 fl. oz.
per acre per 1,000 ft. of row. Make one application per crop
season. For damping-off caused by Pythium or Rhizoctonia
spp. REI: 0-hour. PHI: NA FRAC 04, FRAC 11.
Internal Root Discoloration of
Horseradish - Fusarium and Verticillium
Fungi
This long-lived complex of soil pathogens reduce
marketability by discoloring roots to a black color.
Non-Pesticide
Horseradish | Use disease-free root stocks generated from
tissue-culture. Hot water seed treatment may reduce this
disease in root clones. Use temperatures and times of 115 F
for 10 minutes. Control volunteer horseradish in rotation
years.
Leaf Blight of Carrots - Xanthomonas
Bacteria
Copper products that are labeled for Cercospora may be
helpful; however, bacteria may become resistant to copper
products. Early bacterial leaf blight symptoms may mimic
Alternaria leaf spot.
Bacteria may occur on seed and can survive on carrot debris
in soil. Bacteria spread within a field by rain or overhead
irrigation. Under dry conditions, low levels of bacterial leaf
blight may not result in significant crop loss. Under hot and
wet conditions, high levels of bacterial blight may develop
and lead to premature defoliation and an inability to harvest
the roots via a mechanical harvester.
Non-Pesticide
Carrot | Use disease-free seed. Hot water seed treatment may
reduce this seedborne disease. Use temperatures and times of
122 F for 20 minutes for carrot. Rotate to non-host crops for
2 years. Prompt destruction of the finished crop with tillage
to rapidly breakdown tissue is an important method to
prevent disease build-up.
Pesticide
copper products (copper hydroxide, copper octanoate,
copper oxychloride, copper sulfate, copper diammonium
diacetate complex, cuprous oxide) Carrot | Several
formulations of copper (Badge, Champ, Kocide) products are
labelled for use and may slow the spread of bacterial blight.
See label for directions. REI: 4 to 48-hour. PHI: 0-day.
FRAC M01. OMRI-listed.
Leaf Blight of Root Crops - Alternaria
Fungus
Scout fields to initiate a spray program when foliar blights are
first detected (trace of disease). TOM-CAST with 15 disease
severity values (DSVs) can help carrot farmers time their
fungicide applications for control of foliar blights. See
Disease Forecasting Systems for details. Cercospora leaf spot
is sometimes known as early blight. Alternaria leaf blight is
sometimes known as late blight.
Non-Pesticide
Beet, Carrot, Celeriac, Horseradish, Parsnip, Radish,
Rutabaga, Turnip | Use disease-free seed. Hot water seed
treatment may reduce this seedborne disease. Use
temperatures and times of 122 F for 20 minutes for carrot,
rutabaga and turnip, 122 F for 15 minutes for radish, or 118 F
for 30 minutes for celeriac. Rotate to non-host crops for 2
years. Varieties with partial resistance are available. Prompt
destruction of the finished crop with tillage to rapidly
breakdown tissue is an important method to prevent disease
build-up.
Pesticide
azoxystrobin products (azoxystrobin) Beet, Carrot,
Celeriac, Horseradish, Parsnip, Radish, Rutabaga, Turnip |
Rates vary widely depending on crop and application method.
REI: 4-hour. PHI: 0-day. FRAC 11.
Cabrio EG (20) (pyraclostrobin) Beet, Carrot, Celeriac,
Horseradish, Parsnip, Radish, Rutabaga, Turnip | 8-12 oz.
per acre. REI: 12-hour. PHI: 0-day FRAC 11.
chlorothalonil products (chlorothalonil) Carrot,
Horseradish, Parsnip | Several formulations of chlorothalonil
(Bravo, Echo, Equus) are labeled at various rates and crops.
See label for directions. REI: 12-hour. PHI: 0-day for carrot;
10-day for parsnip; 14-day for horseradish. FRAC M05.
Endura (WG) (boscalid) Beet, Carrot, Celeriac,
Horseradish, Parsnip, Radish, Rutabaga, Turnip | 4.5 oz. per
acre. REI: 12-hour. PHI: 0-day. FRAC 07.
258
Midwest Veg Guide 2022
Midwest Vegetable Guide - 2022

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