Resistant Varieties
Many varieties of vegetable and ornamental plants are resistant, but not immune, to
certain diseases. If a disease is known to occur in your area, use a resistant variety, if
available.
Vascular wilt diseases cannot be controlled by protectant fungicides. Since the
pathogens that cause wilts survive many years in the soil, varietal resistance provides
the best means of disease management. This includes the management of tomato wilts -- look
for tomato seed sources marked VF, which means Verticillium-Fusarium resistant. Other
tomato varieties are marked VFN, which means Verticillium-Fusarium-Nematode resistant.
However, nematodes are not known to be a problem in North Dakota home gardens.
Other diseases best managed by resistant varieties include cabbage yellows, potato
scab, strawberry red stele, cucumber mosaic and fireblight of apple and crabapple.
Information on disease resistance is available from various sources. Seed and nursery
catalogs and several Extension circulars discuss current variety choices that may be
resistant to important diseases.
Disease Free Seed and Transplants
Since many disease-causing organisms survive in the seed, do not save seed from the
garden. Old seed may also have reduced germination and vigor. Purchase good quality seed
and transplants. Purchase seed packaged for the current year -- a date should be printed
on the packet. Inspect plants before purchase and reject any with curled leaves, aphids or
spider mites (look for aphids and spider mites on the lower leaf surface). Reject any
moldy bulbs, sets or other propagative material. Reject six-packs of transplants in which
several plants are missing and have presumably died.
If transplants are started from seed, purchase high quality seed. Sow and transplant
into pasteurized potting medium. Pasteurization is described in Circular PP-744,
"House Plants -- Proper Care and Problem Solving."
Crop Rotation
Change the location of various crops in the garden, each year if space permits. Many
disease-causing organisms do not survive long in the soil if a different crop is planted.
Some exceptions are the tomato wilts, asparagus root rot and cabbage yellows. Once the
soil is infested with the organisms that cause these diseases, it remains infested for a
long time; the only way to manage these sites is to use resistant varieties.
When rotating crops in the garden, rotate between different families of vegetables, as
members of the same family may be susceptible to many of the same diseases. For example,
tomatoes, potatoes, eggplant, and peppers are all members of the potato family and have
many of the same diseases. Cucumbers, melons, and squash are all members of the cucurbit
family. Cole crops or crucifers include cabbage, broccoli, brussels sprouts, cauliflower,
kohlrabi, turnip, radish, and mustard.
Control Weeds
Many weeds harbor disease organisms that can spread to nearby gardens. Most of these
disease organisms are insect-transmitted viruses and mycoplasmas. Destroy weeds in and
around the garden and along fences to destroy the source of these disease-causing
organisms. For example, dandelions harbor the aster yellows mycoplasma; dandelion control
can reduce the amount of aster yellows spread by the aster leafhopper to nearby
susceptible hosts such as marigold or carrots.
Control Insects
Some insects transmit disease organisms. Aphids, for example, transmit several viruses,
including cucumber mosaic virus. The aster leafhopper transmits the aster yellows
mycoplasma to many flowers and certain vegetables (e.g., carrots). The cucumber
beetle transmits the bacterial wilt organism and squash mosaic virus. Control of these and
certain other insects is essential to disease management.
Some insects may cause direct plant damage that can be confused with plant disease. The
tarnished plant bug may inject its saliva into plants and cause a toxic reaction such as
bud death of china aster, dahlia, gladiolus, balsam, salvia, straw flowers and zinnias
this toxic reaction is not technically a plant disease, but resembles one. The saliva of
the potato leafhopper can cause hopper burn on various garden plants, such as garden
beans; this toxic reaction shows as leaf curling and chlorosis (yellowing), stunted
growth, and reduced yield. Hopper burn is more severe in hot, dry weather.
Destroy Diseased Plant Parts
Many diseases can build up and spread rapidly through the production of millions of
fungus spores. Promptly remove diseased plant parts to retard the spread of disease.
Examples where removal is effective, especially if used in combination with fungicides,
include: Botrytis blight (gray mold) of begonia, geranium, peony, tulip, and strawberry;
geranium rust; rust and powdery mildew of rose; black knot, plum pockets, and brown rot of
plum and cherry; tomato leaf spots and fruit rots; cucurbit fruit rots; and powdery mildew
of various ornamentals.
Dispose of Plant Refuse
Disease-causing organisms may survive the winter on diseased plant refuse. Infected
refuse gives diseases an early start. Remove and destroy plant refuse in the fall. Spade
or rototill the remaining refuse into the soil -- this destroys most disease organisms.
Remove and destroy all tomato and potato vines, cucumber and melon vines, rose leaves,
raspberry and strawberry leaves, and peony and hollyhock tops. Remove and destroy all
diseased canes from rose and raspberry bushes. Rake up and destroy all diseased apple
leaves.
Composting crop refuse may destroy disease organisms if the compost heats properly
and is turned frequently. To kill pathogens in the compost pile, the compost must have
a minimum volume of one cubic yard. Turn the pile every two to three days to
provide aeration and mixing. Add sawdust, leaves, etc., to help provide a mixture more
likely to heat properly. Maintain the pile at 65-75 percent moisture (fairly moist, but
not wet). Add water if necessary to maintain the moisture level. These procedures help
maintain high temperatures. Pathogens are killed if the temperature in the pile is 120-160
degrees Fahrenheit for two to three weeks. Check pile temperatures with a candy or meat
thermometer. If the temperature is too low or if turning is not frequent enough, some
pathogens will survive, particularly those near the edges of the pile. See Circular H-885,
"Composting Practices," for further information.
Plant Companion Crops
Two unrelated crops planted in the same area are called companion crops. NDSU has
experimented with various companion crops for several years. The following combinations
have been successful for at least one season at the Carrington Research and Extension
Center. These combinations can greatly reduce the numbers of destructive insects as well
as help reduce disease and more efficiently use soil nutrients. Potatoes have been
successfully planted with beans, corn, and marigolds. Squash has been successfully planted
with nasturtium, corn and borage. Tomato has been successfully planted with chives, onion,
parsley, marigolds, and nasturtiums. Peas are a good companion crop for almost any
vegetable because of their nitrogen fixing ability. Leeks, carrots, onions, and celery can
be interplanted with mutual benefit.
Seed Treatment
Seed treatment is most effective when used with crop rotation. Use fungicide-treated
seed to help ensure good stands and avoid replanting costs. The objectives of seed
treatment are:(1) to kill disease-causing organisms on the seed surface and (2) to protect
the seed and young seedlings from disease-causing organisms in the soil. This helps
promote quick emergence.
Some seed, especially sweet corn, is sold already treated and the packet is marked
"treated."
Treated seed is usually colored red or some other easily identifiable color. If
untreated seed is purchased, the gardener may treat it using recommended chemicals such as
thiram or captan according to the manufacturer's directions.
To treat small paper packets of seed, tear off one corner of the packet. Put about
twice as much chemical in the packet as can be picked up on the first half inch of the
flat end of a toothpick. Shake the packet until the seed is evenly coated with the
chemical.
Purchase seed of cabbage or related plants that is of high quality. For small plantings
it may be best to buy plants started by commercial growers.
Many annual flowers have extremely small seed which should be seeded in flats or
seedbeds containing pasteurized potting mix before planting in the garden. Treat the seed
with captan or thiram or mix captan or thiram with the top 2 l/2 to 3 inches of potting
mix in the seedbed to help obtain a better stand.
Plant only disease-free corms (gladioli), bulbs (tulips), tubers (potatoes -- be sure
to use certified seed potatoes), rhizomes (iris), tuberous roots (tuberous begonia) and
roots (asparagus and rhubarb). Dust with captan or thiram before planting to retard
certain soil-borne diseases. Follow label directions.
When harvesting corms, bulbs and tuberous roots, be sure to remove any discolored ones.
Cure them for several days at 60-70 F in a dry, well-ventilated area. Before storing, dust
them with thiram or captan fungicide to retard storage rot.
Spraying and Dusting Fungicides
General Information
Many leaf (foliar) diseases can be managed by spraying or dusting plants with an
effective fungicide. A few fungicides may be classed as organic; these are discussed
below. Fungicide treatments should be applied at seven to 10-day intervals during humid
weather to protect young growing shoots and replace fungicide washed off by rain or
watering. Plants and fruits must be completely covered with spray or dust for good disease
control.
Most fungicides are protectants. They work on the plant surface and protect against
infection; they do not "cure" infections already established. If considerable
disease is already present, it is too late to use protectant fungicides except to protect
new leaves as they emerge. If disease is not detected early, establish effective control
on new leaves by removing older diseased leaves and providing regular application of a
fungicide.
A few fungicides on the market today are systemic; they move into the plant tissues and
up the plant in the sapstream. Currently, benomyl (several labels), triforine (Funginex),
triadimefon (several labels), and thiophanate-methyl (Green Light Systemic Fungicide).
Triforine, triadimefon,and thiopanate-methyl have some curative properties on established
infections, although they will not make spots disappear. Benomyl will not provide curative
action.
Organic Fungicides
Bordeaux mixture, some other copper fungicides, and lime sulfur are generally
considered as organic by many organizations that certify organically produced crops.
Sulfur, if it comes from a mined source, also may be considered organic by many certifying
organizations. Home gardeners who wish to use only organic products may find these
products helpful in their disease management programs. Compounds that may qualify as
organic are listed in bold type in the fungicide recommendation tables at the end of this
publication.
Fungicide Use Tables
Fungicides for managing home garden vegetable diseases are listed in Table 1. Those for
managing home garden fruit diseases are listed in Table 2. Fungicides for managing
ornamental diseases are listed in Table 3. If a range of doses is given in the tables (eg.
1-1� tablespoons), use the lower rate for disease prevention or when only a little
disease is present; use the higher rate when there is a lot of disease present. There are
3 level teaspoons in a level tablespoon, so a dose of 2/3 tablespoon equals 2 teaspoons.
Sulfur
Sulfur can be used for managing powdery mildew on various plants in the home garden.
These are listed in the tables. Do not apply sulfur when temperatures are above 90 F or
are expected to exceed 90 F during the day as injury may occur.
Combination Products
The home gardener can also purchase general purpose combination dusts or sprays to
control a wide variety of diseases and insects. Although these combinations suppress many
common disease and insect problems, they do not suppress all the diseases or insects which
may attack a plant.
Disease Management
The most effective home garden disease control program uses a combination of practices
to avoid disease damage. These are use of resistant varieties, planting disease-free
plants, rotating garden areas, weed control, insect control, destroying diseased plants or
plant parts, proper fall cleanup and use of fungicides as needed. Such practices may
result in diseases remaining at non-destructive levels. Other practices that help avoid
disease damage include proper watering, using wider row spacing, alternating varieties
from year to year, and interplanting (e.g. planting pole beans with corn) or
growing companion crops.
If gardens are watered after plants are established, apply 1-2 inches of water slowly
enough for it to soak in, then allow the soil surface to dry before another application.
Avoid frequent light waterings and early morning or late evening overhead irrigation.
These practices result in prolonged leaf wetness, which favor disease. To minimize
disease, overhead irrigation should be done in late morning or early afternoon when the
leaves will dry rapidly. However, overhead irrigation at this time of day is very
inefficient, and on hot windy days 33-40 percent of the water may evaporate before it
reaches the ground. Watering with soaker hoses, in-ground furrows, or drip applicators is
better than using sprinklers because the leaves remain dry and water is used efficiently.
Wide row spacing helps reduce disease development by promoting rapid leaf drying; it
also separates plants and reduces the chances of disease spread. Alternating plant
varieties or species also reduces the chances of disease spread from plant to plant.
Fungicides are not always needed if other disease management practices are observed.
However, if disease was severe in recent years or the weather is humid, fungicides may be
essential for reducing disease losses.
Many plants have waxy leaves that are not easily wetted by a spray. Common examples
include cabbage, onion, and iris. Spray tends to form large droplets similar to those that
form on the hood of a freshly waxed car, then the droplets roll off. A spreader-sticker
should be used to help wet waxy foliage and also to retard wash-off of the fungicide in
subsequent rains. Spreader-stickers are available at larger garden care centers. As a
substitute for a spreader-sticker, home gardeners may use 1/4 teaspoon of a mild liquid
detergent per gallon of water. This will help wet the leaf, but will not retard wash-off
in subsequent rains, so is not as effective as a spreader-sticker.
IMPORTANT
All fungicides except sulfur are poisonous and should be handled with care. Sulfur
and many other fungicides are eye and skin irritants. Do not get sulfur or other
fungicides in eyes or on skin. Wash hands after using chemicals. Store chemicals in the
original container in a locked area away from children and pets. Do not transfer chemicals
from the original container to a make-shift container.
Rinse and air dry sprayer after each use. Empty duster at the end of the season; apply
oil or graphite to the leather plunger.
Rx for Control
Read and follow label directions -- this is your prescription for control. The label
lists the ingredients -- it will give the chemical name (a very long name) and the common
name (for example, captan). The label states the percent active ingredients. Some home
garden preparations contain both fungicide and insecticide for both disease and insect
control. Be sure to read the label to determine if the product contains the ingredients
you need to control a specific problem.
Read the label statement entitled "Caution" or "Warning". This
contains important safety information on handling the fungicide. Also read the statements
on environmental hazards, directions for use, storage and container disposal. Read the
section of the label that pertains to the crop being treated and check the harvest
limitations (see below).
Some fungicides have harvest restrictions on food crops -- for example, Ortho
Multi-Purpose Fungicide Daconil 2787 should not be applied to sweet corn within 14 days of
harvest or to green beans within seven days of harvest. These limitations are given in
Tables 1 and 2 and are stated on the labels.
Some products are marketed under a brand name -- for example, Ortho brand captan is
marketed under the name Orthocide; mancozeb is marketed as Dithane M-45, Manzate 200, or
Penncozeb; copper fungicides are marketed as Bordeaux Mixture, Tri Basic Bordeaux, and
under other names; and chlorothalonil is marketed as Ortho Multi-Purpose Fungicide Daconil
2787 (for home gardens), Daconil 2787 (for ornamentals) and Bravo 720 (for farm crops).
The percentage of active ingredients may vary from brand to brand.
Disease Diagnosis
Proper identification of a disease is essential for an accurate prescription for
control. Several types of diseases are easily recognized.
The rusts produce pustules that break through the surface of the leaf and
produce masses of orange to orange-brown powder, which are the spores of the rust fungus.
Powdery mildews produce a cobwebby white growth on the leaf surface, then
develop a white powder, which is a mass of the powdery mildew spores.
Many of the leafspots are described in circulars that discuss diseases of specific
groups of plants, such as apples, stone fruits, cucurbits (cucumber, melon, squash),
tomatoes, potatoes, deciduous trees and evergreen trees.
If an entire plant wilts, the problem may be a root rot, a canker (disease) on
the main stem, or a wilt disease that attacks the vascular (water conducting) system.
Viruses may produce leaves that are mottled green and yellow. Mycoplasmas,
such as aster yellows, may produce plants that are yellow and have a bushy appearance due
to excessive branching. Fungicides are not effective against vascular wilts, viruses or
mycoplasmas.
The information given herein is supplied with the understanding that no discrimination
is intended and no endorsement by the North Dakota State University Extension Service is
implied.
An effort has been made in this publication to represent all products known to be
available across the state.
Products listed in BOLD print in the following tables may be considered
"organic" pest control compounds.
Table 1. Fungicides for disease management in vegetables
-----------------------------------------------------------------------------
Harvest Tablespoons/
Crop Disease Fungicide Limitation* gal. of water
-----------------------------------------------------------------------------
Asparagus Rust mancozeb Apply these
Green Light Broad products only 2
Spectrum Mancozeb after harvest
Fungicide
Bonide Mancozeb Flowable 1-1/3
with Zinc
Bonide Mancozeb Plant 2
Fungicide
-----------------------------------------------------------------------------
Bean Bacterial Bonide Liquid Copper None 1-1/3
blights Fungicide
------------------------------------------------------------------
Rust chlorothalonil
Bonide Liquid Fungicide 7 days 3-2/3
Ortho Multi Purpose 7 days 1
Fungicide
copper + sulfur
Bonide Garden Dust** None See label
sulfur
Green Light**
------------------------------------------------------------------
White mold benomyl
Bonide Benomyl 50% WP 14 days 1-1/2 - 2 tsp.
-----------------------------------------------------------------------------
Carrot Leaf blight Bordeaux mixture
Bonide Copper (Bordeaux) 4-1/2 -
Spray or Dust None 9-1/2 + 2/3
hydrated lime
chlorothalonil
Bonide Liquid Fungicide None 6 - 7
Ortho Multi Purpose None 1
Fungicide
copper
Bonide Rotenone-Copper None See label
Dust
-----------------------------------------------------------------------------
Corn Rust Ortho Multi Purpose 14 days 1
Fungicide
------------------------------------------------------------------
Rust, mancozeb
leaf spot Green Light Broad 7 days 2
Spectrum Mancozeb
Fungicide
Bonide Mancozeb Flowable 7 days 1
with Zinc
Bonide Mancozeb Plant 7 days 1-1/2
Fungicide
-----------------------------------------------------------------------------
Crucifers Downy mildew Bordeaux mixture
(Broccoli, and leaf Bonide Copper (Bordeaux) None 4-1/2 - 6-1/2
Brussels spot Spray or Dust
sprouts, chlorothalonil
cabbage, Ortho Multi Purpose None 1
cauliflower) Fungicide
copper
Bonide Rotenone-Copper Dust
------------------------------------------------------------------
Downy mildew copper
Bonide Liquid Copper None 1-1/3 - 2
Fungicide
Bonide Rotenone-Copper None See label
Dust
chlorothalonil
Bonide Liquid Fungicide None 2
Ortho Multi Purpose None 1
Fungicide
-----------------------------------------------------------------------------
Cucurbits Angular Bordeaux mixture
(Cucumber, leaf spot Bonide Copper (Bordeaux) None 4-1/2 - 11-1/2
melon, Spray or Dust
squash, copper
pumpkin) Bonide Liquid Copper None 1 -1/3
Fungicide
Bonide Rotenone-Copper None See label
Dust
------------------------------------------------------------------
Anthracnose benomyl, 50% None 1/2
Bordeaux mixture
Bonide Copper (Bordeaux) None 4-1/2 - 11-1/2
Spray or Dust
chlorothalonil
Ortho Multi Purpose None 2/3
Fungicide
copper
Bonide Rotenone-Copper None See label
Dust
mancozeb
Bonide Mancozeb Flowable 7 days 4 - 5 tsp.
with Zinc
Bonide Mancozeb Plant 5 days 2 -3 Tbsp.
Fungicide***
------------------------------------------------------------------
Downy mildew Bordeaux mixture
Bonide Copper (Bordeaux) None 4-1/2 - 11-1/2
Spray or Dust
copper
Bonide Rotenone-Copper None See label
Dust
mancozeb
Bonide Mancozeb Flowable None 4 - 5 tsp.
with Zinc
Bonide Mancozeb Plant 5 days 2 - 3 Tbsp.
Fungicide
chlorothalonil
Bonide Liquid Fungicide None 6 - 7 tsp.
Ortho Multi Purpose 7 days 2/3
Fungicide
------------------------------------------------------------------
Powdery benomyl
mildew Bonide Benomyl 50% WP None 1/4 - 1/2 tsp.
Bordeaux mixture
Bonide Copper (Bordeaux) None 4-1/2 - 11-1/2
Spray or Dust
chlorothalonil
Ortho Multi Purpose None 1
Fungicide
copper
Bonide Rotenone-Copper None See label
Dust
copper + sulfur
Bonide Garden Dust** None See label
-----------------------------------------------------------------------------
Onion Downy chlorothalonil
mildew, Ortho Multi Purpose 14 days - green 1
leaf blight, Fungicide
purple mancozeb
blotch Green Light Broad 7 days 1
Spectrum Mancozeb
Fungicide
Bonide Mancozeb Flowable 5 days 5 tsp.
with Zinc
(dry onions only)
Bonide Mancozeb Plant 7 days 3 Tbsp.
Fungicide
(dry onions only)
------------------------------------------------------------------
Downy copper
mildew Bonide Liquid Copper None 4 tsp.
Fungicide
-----------------------------------------------------------------------------
Pea Powdery copper
mildew Bonide Liquid Copper None 4 - 6 tsp.
Fungicide
copper + sulfur
Bonide Garden Dust** None See label
sulfur
Bonide** 24 hours 1-1/2 - 3 Tbsp.
Green Light** 24 hours 2 Tbsp.
Ortho Flotox** None 2-1/2 Tbsp.
-----------------------------------------------------------------------------
Potato Leaf Bordeaux mixture
blights Bonide Copper (Bordeaux) None 4-1/2 - 12
Spray or Dust
chlorothalonil
Bonide Liquid Fungicide None 1-1/2 - 1-4/5
Ortho Multi Purpose None 1/2
Fungicide
copper
Bonide Liquid Copper None Early blight
Fungicide 4 - 6 tsp.
Late blight Late blight
7 tsp.
Bonide Rotenone-Copper None See label
Dust
copper + sulfur
Bonide Garden Dust** None See label
mancozeb
Green Light Broad None 1/2 - 1
Spectrum Mancozeb
Fungicide
Bonide Mancozeb Flowable 14 days 2 -4 tsp.
with Zinc
Bonide Mancozeb Plant 14 days 1 - 2 Tbsp.
Fungicide
-----------------------------------------------------------------------------
Tomato Leaf spots, Bordeaux mixture
leaf blights Bonide Copper None 4-1/2 - 12
(Bordeaux) Spray or
Dust
chlorothalonil
Bonide Liquid Fungicide None 2 - 2-1/3
Ortho Multi Purpose None 1
Fungicide
copper (not recommended
for late blight
management)
Bonide Liquid Copper None 4 - 6 tsp.
Fungicide
Bonide Rotenone-Copper None See label
Dust
copper + sulfur
Bonide Garden Dust** None See label
mancozeb
Green Light Broad 5 days 1/2 - 1
Spectrum Mancozeb
Fungicide
Bonide Mancozeb 5 days 3 - 5 tsp.
Flowable with Zinc
Bonide Mancozeb Plant 5 days 1-1/2 - 2 Tbsp.
Fungicide
------------------------------------------------------------------
Bacterial copper
spot, Bonide Rotenone-Copper None See label
bacterial Dust
speck
-----------------------------------------------------------------------------
*Harvest limitations indicate the minimum amount number of days before harvest
that the last application can be made. None indicates that application can be
made up to harvest.
**Do not apply sulfur when temperatures are greater than 90F. Under those
conditions, plant injury may occur.
***Apply only to melons. Cucumbers are not listed on the label.
Table 2. Fungicides for disease management in fruits
-------------------------------------------------------------------------------
Harvest Tablespoons/
Crop Disease Fungicide Limitations* gal. of water
-------------------------------------------------------------------------------
Apple Fireblight Bordeaux mixture
Dexol Bordeaux None See label**
streptomycin, 21%
Agri-Strep 50 days 1 tsp.***
Bonide Fire Blight Spray None stated 2/5***
--------------------------------------------------------------------
Black rot & Bordeaux mixture
Frogeye Bonide Copper (Bordeaux) None 1 - 1-1/2
leaf spot Spray or Dust
captan
Ortho Home Orchard Spray None 5
Bonide Captan 50% WP None 2
--------------------------------------------------------------------
Powdery benomyl + captan None 1/16 + 1
mildew Bordeaux mixture
Bonide Copper (Bordeaux) None 1 - 1-1/2
Spray or Dust
copper
Bonide Rotenone-Copper Dust None See label
sulfur
Bonide+++ None 1 - 2-1/2 t
Bonide Liquid Sulfur+++ None 2 - 2-1/2 t
--------------------------------------------------------------------
Apple scab benomyl + captan None 1/4 + 2
captan
Ortho Home Orchard Spray None 5
Bonide Captan 50% WP None 2
sulfur
Green Light+++ None See label
Bonide Liquid Sulfur+++ None 2-1/2 tsp.
--------------------------------------------------------------------
Sooty blotch captan
& Fly speck Ortho Home Orchard Spray None 5
Bonide Captan 50% WP None 2
-------------------------------------------------------------------------------
Stone Black knot lime sulfur (dormant spray)
fruits Orthorix None 10+
(Cherry, Bonide Oil & Lime Sulfur None 22-1/2+
plum) Spray
--------------------------------------------------------------------
Brown rot benomyl
Bonide Benomyl 50% WP None 1
Bordeaux mixture
Bonide Copper (Bordeaux) None 9 - 12
Spray or Dust
captan, 14.7%
Ortho Home Orchard Spray None 5
copper
Bonide Rotenone-Copper Dust None See label
sulfur
Bonide+++ None 1 - 3 t
Bonide Liquid Sulfur+++ None 1 - 2-1/2 t
Flotox+++ None 2-1/2
Green Light+++ 24 hours 2
--------------------------------------------------------------------
Leaf spot benomyl
Bonide Benomyl 50% WP None 1
benomyl + captan None 1/2 - 2
captan, 50%
Ortho Home Orchard Spray None 5
--------------------------------------------------------------------
Plum pockets lime sulfur (dormant spray)
Orthorix None 10
Bonide Oil & Lime Sulfur None 22-1/2 T
Spray
--------------------------------------------------------------------
Powdery benomyl + captan None 3/4 + 1-1/2
mildew sulfur
Bonide+++ None 1 - 3
-------------------------------------------------------------------------------
Grape Powdery copper
mildew, Bonide Liquid Copper None 4 - 6 tsp.
dead arm, Fungicide (for mildews)
downy sulfur
mildew Flotox+++ None 2-1/2
mancozeb
Green Light Broad Spectrum 66 days 2 - 4 tsp.
Mancozeb Fungicide
Bonide Mancozeb Flowable 66 days 3 - 4 tsp.
w/ Zinc
captan
Ortho Home Orchard Spray None 5
Bonide Captan 50% WP None 2
-------------------------------------------------------------------------------
Brambles Anthracnose copper
(Raspberry, Bonide Liquid Copper None 4 - 6 tsp.
blackberry) Fungicide
--------------------------------------------------------------------
Anthracnose lime sulfur (dormant spray)
and Orthorix None 10=
spur blight Bonide Oil & Lime Sulfur None 22-1/2=
Spray
--------------------------------------------------------------------
Powdery benomyl, 50% 3 days 3/4
mildew sulfur
Bonide+++ 24 hours 2 - 2-1/2
--------------------------------------------------------------------
Fruit rot Green Light Broad Spectrum
Mancozeb Fungicide 30 days 1 - 2
--------------------------------------------------------------------
Yellow rust Bonide Liquid Copper Fungicide None 4 - 6 tsp.
-------------------------------------------------------------------------------
Strawberry Gray mold benomyl
(Botrytis) Bonide Benomyl 50% WP None 1/2 - 1 tsp.**
captan
Ortho Home Orchard Spray None 5
Bonide Captan 50% WP None=== 2
---------------------------------------------------------------------
Leaf spot benomyl
and Bonide Benomyl 50% WP None 1/2 - 1 tsp.==
leaf scorch copper
Bonide Liquid Copper None 1 - 1-1/3
Fungicide
Bonide Rotenone-Copper Dust None See label
--------------------------------------------------------------------
Powdery benomyl
mildew Bonide Benomyl 50% WP None 1/2 - 1 tsp.==
sulfur
Bonide Sulfur+++ None 1 - 2
Bonide Liquid Sulfur None 1/3
-------------------------------------------------------------------------------
* Harvest limitations indicate the minimum amount number of days before harvest
that the last application can be made. None indicates that application can be
made up to harvest.
** See label; apply as a dormant or delayed dormant spray. Do not apply after
fruits have formed as russeting may occur.
***Spray every 5 days during bloom and after hail.
+ Dormant spray. On plum and cherry, all black knot cankers should be pruned out
before spraying with lime-sulfur.
++ This treatment is less effective than others listed.
+++Do not apply when temperatures exceed 90F, as injury may occur.
= Apply in early spring when leaf buds are just showing green (green tip stage).
== Apply at 10% bloom and at full bloom; use � tablespoon/gal. Every 10-14 days
thereafter.
===Apply throughout season, from first growth and every 7 days, thereafter;
when plants are bearing and disease is severe, treat after each picking.
Table 3. Fungicides for disease management in ornamentals
-------------------------------------------------------------------------------
Plant Rate/gal.
species Disease Fungicide of water
-------------------------------------------------------------------------------
Ash, green Anthracnose Bordeaux mixture
Acme Bordeaux Mixture See label
lime sulfur (dormant spray)
Orthorix -1/2 cups*
Acme Lime Sulfur Spray See label*
chlorothalonil
Daconil 2787 Flowable, 40.4% 2/3
thiophanate-methyl
Green Light Systemic Fungicide 2-1/2 tsp.
-------------------------------------------------------------------------------
Aster Rust triforine
Funginex, 6.5% 1
triadimefon
Bonide Bayleton Systemic Fungicide 2 - 4
thiophanate-methyl
Green Light Systemic Fungicide 1 - 2
-------------------------------------------------------------------------------
Begonia Gray mold mancozeb
blight Bonide Mancozeb Flowable with Zinc 1
(Botrytis)
---------------------------------------------------------------
Powdery triforine
mildew Funginex, 6.5% 1
-------------------------------------------------------------------------------
Begonia, Rot of captan See label for rates of
tuberous tuberous each of these products
root thiram
(Many broad spectrum blends of products
contain one of these fungicides)
-------------------------------------------------------------------------------
Chrysanthemum Powdery sulfur
mildew Flotox 2-1/2
Green Light 2
-------------------------------------------------------------------------------
Crabapple, Frogeye chlorothalonil
ornamental leaf spot Dexol Fungicide containing
Daconil 2787 (12.5%) See label
Daconil 2787 WDG 2/3
Daconil 2787 Flowable, 40.4% 2/3
Ortho Multi Purpose Fungicide 3/4
---------------------------------------------------------------
Powdery triadimefon
mildew Green Light Fung-Away 1 - 2
Bonide Bayleton Systemic Fungicide 2 - 4
---------------------------------------------------------------
Rust chlorothalonil
Dexol Fungicide containing
Daconil 2787 (12.5%) See label
Daconil 2787 WDG 2/3
Daconil 2787 Flowable, 40.4% 2/3
Ortho Multi Purpose Fungicide 3/4
thiophanate-methyl
Green Light Systemic Fungicide 1
triadimefon
Bonide Bayleton Systemic Fungicide 1
Green Light Fung-Away 1 - 2
---------------------------------------------------------------
Applescab chlorothalonil
Dexol Fungicide containing
Daconil 2787 (12.5%) See label
Daconil 2787 WDG 2/3
Daconil 2787 Flowable, 40.4% 2/3
Ortho Multi Purpose Fungicide 3/4
-------------------------------------------------------------------------------
Dahlia Powdery triadimefon
mildew Bonide Bayleton Systemic Fungicide 2 - 4
Green Light Fung-Away 1 - 2
triforine
Funginex, 6.5 % 1
sulfur
Ortho Flotox 2-1/2
-------------------------------------------------------------------------------
Delphinium Powdery triadimefon
mildew Bonide Bayleton Systemic Fungicide 2 - 4
Green Light Fung-Away 1 - 2
triforine
Funginex, 6.5 % 1
-------------------------------------------------------------------------------
Geranium Gray mold chlorothalonil
blight Dexol Fungicide containing
(Botrytis) Daconil 2787 (12.5%) See label
Daconil 2787 WDG 2/3
Daconil 2787 Flowable, 40.4% 2/3
Ortho Multi Purpose Fungicide 3/4
triadimefon
Bonide Bayleton Systemic Fungicide 2 - 4
---------------------------------------------------------------
Rust chlorothalonil
Dexol Fungicide containing
Daconil 2787 (12.5%) See label
Daconil 2787 WDG 2/3
Daconil 2787 Flowable, 40.4% 2/3
Ortho Multi Purpose Fungicide 3/4
triadimefon
Green Light Fung-Away 1/3 - 2/3
-------------------------------------------------------------------------------
Gladiolus Leaf and chlorothalonil
flower Dexol Fungicide containing
spot Daconil 2787 (12.5%) See label
(Botrytis) Daconil 2787 WDG 2/3
Daconil 2787 Flowable, 40.4% 2/3
Ortho Multi Purpose Fungicide 3/4
mancozeb
Green Light Broad Spectrum Mancozeb
Fungicide 1/3
---------------------------------------------------------------
Corm rot captan See label for rates of
each of these products
thiram
(Many broad spectrum blends of products
contain one of these fungicides)
-------------------------------------------------------------------------------
Hawthorn Rust chlorothalonil
Dexol Fungicide containing
Daconil 2787 (12.5%) See label
Daconil 2787 WDG 2/3
Daconil 2787 Flowable, 40.4% 2/3
Ortho Multi Purpose Fungicide 3/4
triadimefon
Bonide Bayleton Systemic Fungicide 2 - 4
Green Light Fung-Away 1/3 - 2/3
-------------------------------------------------------------------------------
Hollyhock Rust chlorothalonil
Dexol Fungicide containing
Daconil 2787 (12.5%) See label
Daconil 2787 WDG 2/3
Daconil 2787 Flowable, 40.4% 2/3
Ortho Multi Purpose Fungicide 3/4
triadimefon
Bonide Bayleton Systemic Fungicide 2 - 4
Green Light Fung-Away 1/3 - 2/3
-------------------------------------------------------------------------------
Horse Leaf blight, chlorothalonil
Chestnut, leaf blotch Dexol Fungicide containing
Buckeye Daconil 2787 (12.5%) See label
Daconil 2787 WDG 2/3
Daconil 2787 Flowable, 40.4% 2/3
Ortho Multi Purpose Fungicide 3/4
-------------------------------------------------------------------------------
Iris Leaf spot chlorothalonil
Dexol Fungicide containing
Daconil 2787 (12.5%) See label for rates
Daconil 2787 WDG 1/2
Daconil 2787 Flowable, 40.4% 1/2
Ortho Multi Purpose Fungicide 2/3
thiophanate-methyl
Green Light Sytemic Fungicide 2-1/2 tsp.
(Use a spreader-sticker)
triadimefon
Bonide Bayleton Systemic Fungicide 2 - 4
Green Light Fung-Away 1 - 2
-------------------------------------------------------------------------------
Lilac Powdery triforine
mildew Funginex, 6.5% 1/3
triadimefon
Green Light Fung-Away 1 - 2
-------------------------------------------------------------------------------
Lily Gray mold chlorothalonil
blight Dexol Fungicide containing
(Botrytis) Daconil 2787 (12.5%) See label
Daconil 2787 WDG 1/2
Daconil 2787 Flowable, 40.4% 1/2
Ortho Multi Purpose Fungicide 2/3
-------------------------------------------------------------------------------
Oak Anthracnose Bordeaux mixture
Dexol Bordeaux See label
Acme Bordeaux See label
lime sulfur
Ortho Dormant Season Control 1-1/2 cups*
Bonide Oil & Lime Sulfur Spray 22-1/2*
Acme Lime Sulfur Spray See label*
-------------------------------------------------------------------------------
Petunia Gray mold chlorothalinol
(Botrytis) Dexol Fungicide containing
and Daconil 2787 (12.5%) See label
Phytophthora Daconil 2787 WDG 1/2
blight Daconil 2787 Flowable, 40.4% 1/2
Ortho Multi Purpose Fungicide 2/3***
-------------------------------------------------------------------------------
Phlox Powdery triforine
mildew Funginex, 6.5% 1
-------------------------------------------------------------------------------
Poplar Marssonina chlorothalonil
leaf spot Dexol Fungicide containing
Daconil 2787 (12.5%) See label
Daconil 2787 WDG 1/2
Daconil 2787 Flowable, 40.4% 1/2
Ortho Multi Purpose Fungicide 2/3
---------------------------------------------------------------
Rust triforine
Funginex, 6.5% 1
-------------------------------------------------------------------------------
Rose Blackspot Bordeaux mixture
Bonide Copper (Bordeaux) Spray or Dust
captan
Bonide Captan 50% WP 1-2/3
chlorothalonil
Dexol Fungicide containing
Daconil 2787 (12.5%) See label
Daconil 2787 WDG 1/2
Daconil 2787 Flowable, 40.4% 1/2
Ortho Multi Purpose Fungicide 2/3
mancozeb
Green Light Broad Spectrum Mancozeb Fungicide 1
thiophanate-methyl
Green Light Systemic Fungicide 2-1/2 tsp.
triforine
Funginex, 6.5% 1
---------------------------------------------------------------
Browncanker lime sulfur
Orthorix 1-1/2 cups*
Bonide Oil & Lime Sulfur Spray 22-1/2 T*
Acme Lime Sulfur Spray See label*
---------------------------------------------------------------
Powdery chlorothalonil
mildew Dexol Fungicide containing
Daconil 2787 (12.5%) See label
copper
Bonide Liquid Copper Fungicide 1-1/3 - 2
triforine
Funginex, 6.5% 1
sulfur
Ortho Flotox 2-1/2
---------------------------------------------------------------
Rust chlorothalonil
Dexol Fungicide containing
Daconil 2787 (12.5%) See label
triforine
Funginex, 6.5% 1
-------------------------------------------------------------------------------
Snapdragon Powdery triforine
mildew Funginex, 6.5% 1
triadimefon
Green Light Fung-Away 1 - 2
-------------------------------------------------------------------------------
Spruce Rhizosphaera Bordeaux mixture
needlecast Dexol Bordeaux See label+
Acme Bordeaux Mixture See label+
chlorothalonil
Daconil 2787 WDG 2-1/4+
Daconil 2787 Flowable 40.4% 2-1/2+
Ortho Multi Purpose Fungicide 3+
-------------------------------------------------------------------------------
Tulip Fire chlorothalonil
(Botrytis) Daconil 2787 WD 2/3
-------------------------------------------------------------------------------
Zinnia Powdery chlorothalonil
mildew Daconil 2787 WDG 2/3
Daconil 2787 Flowable, 40.4% 2/3
Ortho Multi Purpose Fungicide 3/4
triforine
Funginex, 6.5% 1
triadimefon
Green Light Fung-Away 1 - 2
-------------------------------------------------------------------------------
* Dormant spray. Apply before budbreak.
** Do not apply sulfur during periods of high temperatures (above 90 F) as plant
injury may occur.
***May cause discoloration of blooms in some varieties.
+ Apply when shoots are 1/2 - 2 inches long; make a second application in three
to four weeks.
ATTENTION COMMERCIAL APPLICATORS
If a homeowner formulation of a fungicide is listed in this publication, check labels
for commercial formulations of the same active ingredient.
PP-469 (Revised), June 1994
Reviewed and reprinted February 1995
