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provides control of peach scab and cherry leaf spot, and
there is some evidence of rust and shot-hole suppression.
As with any sterol inhibitor, Indar should be mixed or
rotated with other non-sterol inhibitor fungicides to avoid
the development of resistant pathogens.
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 Since bacterial plant pathogens can become resistant
to anti-biotics, alternation of Mycoshield with other
materials, such as Tennecop, should be considered. This
strategy is particularly important for highly susceptible
cultivars which have a higher rate of development of
disease.
Mycoshield is also registered for use in controlling
fire blight on pear. Some pearvarieties, especially the
Asian pears, are sensitive to this anti-biotic and may
show injury.
Nova 40WP (myclobutanil) is a sterol-inhibiting
fungicide that is effective against brown rot, has some
activity against powdery mildew, but weak against peach
scab. It is labeled for use during bloom for blossom
blight control.
On apples, Nova is registered for control of scab,
powdery mildew, and cedar apple rust. When used in a
protectant schedule, the postbloom sprays should include
a non-related protectant fungicide to guard against
resistance development. For post-infection scab control,
Nova should be applied within 96 hours from the start of
the infection period. As a curative spray, Nova can
suppress sporulation of lesions, but this approach requires
several applications.
Orbit 3.6EC(propiconazole)is an excellent
fungicide for control of brown rot on peach, nectarine, and
plum. It is not labeled for use on cherry or prunes. For
brown rot control, it can be used during both the blossom
blight (bloom) and fruit rot (preharvest) periods.
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Penncozeb 80WP, Penncozeb DFsee mancozeb
Polyram 80DF (metiram)is an EBDC fungicide
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mixture, the main component being ammoniates of zinc
EBDC. On apple, it is effective as protectant sprays for
control of scab, cedar-apple rust, sooty blotch, and fly
speck. This fungicide has no activity against powdery
mildew. As with the mancozeb fungicides, Polyram can
be used at full rate prior to bloom or at half this rate for an
extended application program through second cover.
Procure 50WS (triflumizole)is a relatively new
sterol inhibiting fungicide with activity against powdery
mildew, scab, and rust on apple and powdery mildew and
scab on pear. This fungicide is readily absorbed, locally
systemic, and can act as an anti-sporulant when applied to
lesions already present. In addition to being a protectant,
Procure can be applied up to 72 hours post-infection when
used at its higher 4 oz per 100 gallon rate.
Ridomil 2E (metalaxyl), Ridomil Gold EC
(mesenoxam)provides excellent control of root and collar
rot caused by Phytophthora species on both pome and
stone fruit. Up to three applications of the 2E formulation,
each at 2 gallons per treated acre, are allowed per season.
A treated acre is defined as the actual surface area contacted
with an application, i.e., the tree row. Typically, two
sprays are applied in spring, the first being in early April,
followed by one in fall, usually October. Optimum timing
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Maneb 80WP (manganese EBDC)is an excellent
fungicide in terms of its broad range of activity against
many plant-pathogenic fungi. It is registered for use on
apple to control the same diseases listed under mancozeb.
However, when maneb is used alone, without added zinc,
it has a tendency to injure apple trees. Consequently,
mancozeb is considered a better choice.
Mancozeb (coordination product of zinc ion +
manganese EBDC)is a broad -spectrum fungicide
registered for use in controlling scab, rusts, sooty blotch,
fly speck, and Fabraea leaf spot on pome fruit. Available
mancozeb products are Dithane, Manzate, and Penncozeb.
No mancozeb materials are labeled for use on stone fruit.
Mancozeb can be applied in one of two ways. When
used at full rate, the fungicide is appliedfrom half-inch
green tip through bloom. When used at half rate in
combination with another fungicide, sprays can be applied
through second cover. This latter approach is called
"extended application".
The mancozeb materials have maximum application
limits in terms of amount of fungicide that can be applied
per acre each year; see labels for product-specific amounts.
Also, EBDC fungicides cannot be applied within 77 days
of harvest.
biotic extremely effective against bacterial spot of stone
fruit. It is a brand of agricultural Terramycin. The desired
concentration for control is 150 ppm, or 12 oz of material
per 100 gallons of water applied.
Since it has a short residual of only seven days,
terramycin must be applied on a weekly schedule
beginning at shuck split. Furthermore, this bactericide is
most effective when it gets inside the plant tissue. Thus,
applications are best made when conditions allow slow
drying, such as during the evening when relative
humidity tends to be higher. This approach greatly
improves tissue penetration and subsequent control.
For effective control of bacterial spot using this anti-
biotic, complete spray coverage is also critical. It is
important to use a spray volume that thoroughly wets the
foliage and fruit to the point of runoff. Typical volumes
are 3 gallons per tree for planting densities of 80 trees per
acre, which translates into 240 gallons of spray per acre.
For trees of different sizes and/or densities, adjust the
volume to maintain good wetting, but maintain the
concentration at 150 ppm.
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