New fungicides for small fruit crops in Michigan
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Various
new(er) fungicides are available for use on fruit crops in Michigan.
Some of these you may already know and others you may be less familiar
with. The fungicides are listed in alphabetical order with relevant
information on the crops they are labeled for and
guidelines/restrictions. As with all fungicides, read the label
carefully before use. Labels and material data safety sheets (MSDS) can
be found on the following website: www.cdms.net. Descriptions of all fruit fungicides and efficacy ratings of recommended fungicides can be found in E-154 (Michigan Fruit Management Guide).
AgriStar Sonoma (myclobutanil) is a generic version of Rally,
which used to be called Nova. It is labeled for broad-spectrum disease
control in grapes, apples, and stone fruit. Note that AgriStar Sonoma is
not labeled for other berry crops, whereas Rally is. The REI is 24
hours and the PHI is 1 day for stone fruit is and 14 days for apples and
grapes. The efficacy of this product has not been specifically
evaluated in Michigan.
Forum (dimethomorph) is a new, systemic fungicide for
control of downy mildew in grapes. Use Forum as a preventive application
before infection occurs. The minimum application interval is 7 days.
Performance may be improved by using Forum as a tank mix with another
fungicide. The addition of a spreading/penetrating adjuvant is
prohibited. Do not make more than 5 applications per year, and no more
than one application before switching to a fungicide with a different
mode of action. Forum may be applied through irrigation systems with
restrictions (see the label). Forum is not for use in greenhouse and
transplant production. The REI is 12 hours and the PHI is 28 days. Forum
has not been evaluated for disease control in Michigan.
Iprodione (iprodione) has the same active ingredient as
Rovral. It is a contact fungicide with locally systemic properties. It
is labeled on grapes, cherries, peaches, nectarines, plums, apricots,
blueberries, strawberries, raspberries, blackberries, gooseberries, and
currants. Note that Iprodione is labeled for blueberries but Rovral is
not. Thorough coverage is essential for effective control. Alternating
Iprodione with fungicides with a different mode of action may delay the
buildup of resistant pathogen strains. Do not exceed a 4-spray maximum
for wine grapes and berries-, a 2-spray maximum for stone fruit, and a
1-spray maximum for table grapes and strawberries. Do not apply after
first fruiting flower in strawberries or after petal fall in stone
fruit. Iprodione may be applied through irrigation systems with
restrictions (see the label). The spray suspension should be applied
within 24 hours of preparation and the pH of the spray solution should
be buffered to 5.0-7.0 if necessary to prevent potential active
ingredient degradation. The efficacy of this product has not been
specifically evaluated in Michigan.
Legion (fosetyl-Al) has the same active ingredient as
Aliette. It is available as an 80 WDG formulation. This product is
labeled for control of Phytophthora collar and root rot and fire blight
in apples and pears (bearing and non-bearing) and apple blister spot in
bearing trees; Phytophthora collar and root rot in stone fruit
(non-bearing); Phytopthora and anthracnose (and suppression of Phomopsis
and Alternaria fruit rot) in blueberries; Phytophthora root rot in
raspberries, blackberries, and cranberries; downy mildew in grapes; and
red stele and leather rot in strawberry. Do not tank mix Legion 80 WDG
with copper compounds or apply to foliage that bears copper residues
from previous sprays as this could result in phytotoxicity to crops.
Stickers, spreaders and wetting agents are not recommended with this
product. Legion is acidic in nature and must not be tankmixed with
acid-type compatibility spray adjuvants, such as Buffit Spray Aide,
Triton AG-44M, or with adjuvants that aid foliar penetration, such as
Herbex or Induce. The REI is 12 hours. The PHI is 12 hours for
blueberries and strawberries, 14 days for apples and pears (365 days in
non-bearing pome and stone fruit trees), 15 days in grapes, 30 days in
cranberries, and 60 days in raspberries and blackberries. This product
has not been specifically evaluated in Michigan.
MetaStar (metalaxyl) has the same active ingredient as
Ridomil. MetaStar is for soil application only and is not to be used for
foliar applications, except in solutions used to dip plants. MetaStar
is labeled for control of Phytopthora diseases in apples, stone
fruit, blueberries, cranberries, raspberries, strawberries. This label
is for field use only and is not intended for use on transplant trays,
greenhouses, lath houses, float houses, hydroponic production, or in
bedding plant structures. MetaStar may be applied through irrigation
systems with restrictions (for instructions see the label). Applications
are usually made in the spring and the fall. The REI is 48 hours and
the PHI is 45 days for raspberries and cranberries. In strawberries, an
application at fruit set is allowed for control of leather rot. No PHI
is indicated for the other crops if application instructions are
followed.
Mettle (tetraconazole) is a new sterol inhibitor
fungicide. It is a systemic fungicide labeled for control of powdery
mildew and black rot in grapes. When a post-infection application is
used for black rot, it is recommended within 72 hours of an infection
period. Mettle is absorbed quickly into the plant tissue and is rainfast
within 2 hours of application. Do not make more than two applications
of Mettle to grapes per year. The maximum amount of Mettle allowed per
season is 10 fluid ounces and there must be at least 14 days between
applications. Do not apply Mettle through any kind of irrigation system.
The REI of Mettle is 12 hours and the PHI is 14 days. Mettle has not
been tested for disease control in Michigan vineyards.
Nutrol (monopotassium phosphate; 50% P2O5 and 32% K2O)
is a water-soluble fertilizer (0-52-32) as well as a fungicide against
powdery mildew. This product is labeled for control of powdery mildew in
apples, stone fruits, and grapes. It acts primarily as a contact
fungicide. Nutrol will not cause phytotoxicity, even at high
concentrations. Nutrol is a non-toxic, environmentally friendly product
that is exempt from residue tolerances. It can also be used as a pH
buffer to prevent alkaline hydrolysis of pesticides. A 1 percent
solution will have a pH between 4.5 and 6.0. Nutrol is compatible with
most commonly used agricultural chemicals. The PHI is 0-days. This
product has not been evaluated in Michigan.
Rampart (mono- and dipotassium salts of phosphorous
acid; equivalent to 3.9 lb phosphorous acid per gallon) is a systemic
phosphite fungicide labeled for apples, cherries, peaches, nectarines,
plums, apricots, blueberries, strawberries, raspberries, blackberries,
cranberries, gooseberries, and currants. The target diseases listed are
root rots (Phytophthora, Pythium, Fusarium, Rhizoctonia), downy and
powdery mildew, anthracnose, and bacterial diseases. Application is
foliar, aerially, as a root dip or through the irrigation system (with
restrictions). In fruit trees, the product may also be applied via trunk
injection. Do not apply at less than 3-day intervals. Do not apply to
plants that are dormant, or heat or moisture stressed. To avoid copper
phytotoxicity, do not apply to plants that have been treated with
copper-based compounds at less than 20-day intervals. Allow foliage to
dry completely after application. Do not apply when conditions favor wet
tissue for prolonged periods greater than four hours. The REI is four
hours and the PHI is 0 days. This product has not been evaluated for
disease control in Michigan.
Ranman (cyazofamid) is a new fungicide for control of
downy mildew in grapes. Ranman has limited systemic activity, so should
be applied in a preventive mode. Make fungicide applications on a 10-14
day schedule when disease warning systems forecast disease infection
periods or when conditions are favorable for disease development. Do not
apply more than 6 sprays of Ranman per season and no more than 3
consecutive sprays before switching to fungicides with different modes
of action for the next three applications. Do not use any surfactant
with Ranman. Application water volumes for ground application should at
least be 100 gal per acre. Ranman may be applied through irrigation
systems with restrictions (for instructions see the label). The REI is
12 hours and the PHI is 30 days. This product has not been evaluated for
disease control in Michigan.
Regalia (extract of Reynoutria sachalinensis =
giant knotweed) is a plant extract-based biofungicide that can be used
in organic production. The proposed mode of action is by increasing the
plant’s natural defenses. This induced resistance is not systemic but is
there is some translaminar protection. The resistance reaction takes 1
to 2 days to develop. Light is required for best results. Regalia should
therefore be used as a preventative treatment. Applications have to be
repeated every 7-14 days to protect new growth. Regalia is labeled for
control of various diseases of apples, pears, cherries, peaches,
nectarines, plums, apricots, grapes, blueberries, raspberries,
blackberries, gooseberries, and other berry crops. Regalia has a 0-day
PHI and a 4-hour REI. In a blueberry trial in Michigan, Regalia provided
good control of mummy berry and moderate control of anthracnose. In
grapes, Regalia showed good control of powdery mildew, and moderate
control of downy mildew and Botrytis bunch rot. More trials are needed
to assess this product in Michigan fruit crops.
TebuStar (tebuconazole) has the same active ingredient as
Elite. Tebustar is labeled for cherries, peaches, nectarines, and
grapes. The PHI is 0 days for stone fruit and 14 days for grapes. The
efficacy of this product has not been specifically evaluated in
Michigan.
Topaz (mono- and dipotassium salts of phosphorous acid;
3.9 lb phosphorous acid per gallon) is a systemic phosphite fungicide
labeled for apples, cherries, peaches, nectarines, plums, apricots,
blueberries, strawberries, raspberries, blackberries, cranberries,
gooseberries, and currants. The target diseases listed are root rots (Phytophthora, Pythium, Fusarium, Rhizoctonia),
downy and powdery mildew and fire blight. Application is foliar,
aerially, as a root dip or through the irrigation system (with
restrictions). Do not apply at less than 3-day intervals. Do not apply
to plants that are dormant, or heat or moisture stressed. To avoid
copper phytotoxicity, do not apply to plants that have been treated with
copper-based compounds at less than 20-day intervals. Allow foliage to
dry completely after application. Do not apply when conditions favor wet
tissue for prolonged periods greater than four hours. The REI is four
hours and the PHI is 0 days. This product has not been evaluated for
disease control in Michigan.