CONNECTICUT FRUIT GROWER'S NEWSLETTER
April 8, 1998
In this issue:
* The first 1998 Twilight Orchard Meeting - April 22
* UV pasteurization update
* Apple disease update
* Scab Risk
* Update on Rovral for peaches
* 1998-1999 New England Apple Pest Management Guide update
* Resistance is futile
* Minimum wage increase
* Renewal reminder for Fruit Growers Newsletter
The first 1998 Twilight Orchard Meeting will be hosted by the Holmbergs
at Holmberg Orchard in Gales Ferry on Wednesday, April 22. The meting will
begin at 5:00 PM.
Directions: Depending on where you are coming from, take 395 north or south
to Exit 79A (Mohegan-Pequot Bridge Exit). Stay on Exit for approximately
2_ miles. Cross Thames river and turn right at light. Proceed approximately
3/4 miles on Route 12 south. Orchard is on hill directly behind farm market
(follow the signs).
The second 1998 Twilight Orchard Meeting will be hosted by the Bishop's
at their cider mill in Guilford on Tuesday, May 19. The meeting will begin
at 5:00 PM.
Directions: From New Haven, heading north on I-95, take Exit 57. Turn right
at the end of the exit. Bishops' stand is about _ mile after the exit. The
cider mill is behind the stand on the lower level. Heading south on I-95,
take Exit 57 and turn left at the end of the exit; follow the previous instructions.
UV
When Cornell University microbiologist and food safety expert Randy Worobo
unveiled a new, low-cost alternative to thermal pasteurization before 150
apple growers and cider producers at the New York State Horticultural Society's
annual meeting in Rochester in early January, he did not realize the amount
of interest it would generate.
At the meeting, Worobo identified ultraviolet light as a possible answer
to E. coli 0157:H7 contamination of fresh cider and fruit juices. Since,
then he has been inundated with requests for information and has been an
invited speaker at several meetings.
"The new design for a UV pasteurization unit should be perfect for
small cider producers," according to Worobo, and has shown very promising
results in preliminary testing. It is about one-quarter of the price of
a thermal pasteurization unit, small, economical to run, and very user-friendly.
In the process unveiled at the meeting, a thin film of cider was pumped
past UV light at the rate of about 3 gallons per minute. Tests have shown
that this particular design reduced E. coli 0157:H7 contamination from 100,000
microorganisms per ml to 1 organism per ml in a single pass. At the time,
Worobo was hopeful that tests would prove effective against other pathogens
as well.
Since its introduction in January, Worobo, who works in the Food Safety
& Technology Department at the New York State Agricultural Experiment
Station in Geneva, NY, and the two engineers who developed the unit, Patrick
Borrelli and Phil Harman, have made some modifications, streamlined the
process, and come up with a new machine. Borrelli and Harman are from Rochester-based
FPE, Inc.
"The engineers have now addressed the small cider processors' need
to have a unit operating at 180 gallons per hour with the possibility of
operating it at 540 gallons per hour with additional UV components,"
said Worobo. The new unit is extremely compact and simple to turn. It wheels
into place and only needs to be plugged in to be operational. The unit is
in the final set of confirmation tests to ensure that the equivalent to
thermal pasteurization is being met with a broad range of pathogens that
are associated with apple cider. Numerous equipment distributors have expressed
interest in representing FPR Inc. for wholesaling the apparatus.
In addition to controlling pathogens in fruit juices, the UV apparatus is
being tested as a means to control problematic spoilage organisms for various
fruit juices.
In addition to cider producers, others have expressed interest in this new
technology, but Joe Corby of New York State Ag and Markets was quoted as
saying, "This may be the silver bullet that saves the cider industry,"
at an FPA Apple Cider Inspections Workshop in Buffalo, NY, in February.
Numerous people in various state and federal agencies as well as Julia Daily
of the US Apple Association have offered assistance in "fast-tracking"
this apparatus through FDA approval. Presently, sensory tests conducted
to food scientists at the Station and nutritional analyses are being performed
on the UV treated apple cider.
Nationwide, isolated outbreaks of contamination of fresh apple cider and
fruit juices by the bacteria E. coli 0157:H7 have caused some health problems
and created a crisis of confidence among some consumers in the past few
years. The more virulent strain of E. coli was first identified in 1982.
Producers and consumers are clamoring for more information and recommendations
for safe production practices. Last year, thermal pasteurization was the
process of choice, but the thermal pasteurization units can cost between
$12,000 and $30,000 and are out of the reach of most small producers who
rely on income generated during a four-week season in the fall to cover
the costs of publication.
"Preliminary tests indicate UV light causes no sensory changes in the
juice," said Worobo. Further testing on feasibility and effectiveness
is being conducted by Borrelli, Harman, and Worobo, in conjunction with
food specialists at the Experiment Station.
The unit could cost as little as $6,000 FPE, Inc., has applied for a patent.
An unusually high proportion of apple scab ascospores were mature (colored)
by the time trees reached the green-tip bud stage on March 27. Spore maturity
was hastened by a mild winter with enough rains to keep leaf litter moist.
In many years with limited snow cover, leaf litter becomes "freeze-dried",
development of apple scab in the leaf litter is arrested, and spore maturation
is delayed in spring. This year we had relatively little snow cover, but
mild temperatures and adequate moisture (especially during February and
March) allowed for rapid ascospore development.
As of March 26, maturity was at 22% but spore discharges in the shooting
tower were still quite low. With the squash-mount method of assessing spore
maturity, there is always a lag between the time that spores appear mature
in squash mounts and the time that they actually begin discharging. Based
on previous experience, we expect significant ascospore discharges to begin
when spore maturity reaches 15-17%. Warm weather over the past weekend has
certainly promoted further rapid development of ascospores. Significant
spore discharges are expected with the next rain.
Do Orchards Need to Be Sprayed As Soon As Spores Are Mature?
Not necessarily! It really doesn't matter what proportion of spores
are mature
if there is no overwintering inoculum in the orchard. Because dry weather
prevailed throughout most of New York last year, most orchards had little
or no apple scab. Low inoculum levels reduce the risks that would otherwise
be associated with early spore maturity. However, orchards growing next
to abandoned blocks or adjacent to other unusual sources of inoculum should
be protected against scab before the next rain.
An Early Season Can Increase the Risks of Scab Epidemics
Scab problems are always worse if scab gets an early start. When scab infections
occur early in the season, there is more opportunity for the fungus to produce
conidia and initiate secondary infections while fruit and leaves are still
at peak susceptibility. Under normal fungicide programs, apples are at peak
susceptibility for economic damage from apple scab when trees are between
full bloom and first cover because this is the period when total
leaf area is expanding most rapidly and fruit is at peak susceptibility.
Within a week after petal fall, the risk of scab infections begins to decrease
because leaves produced during the initial growth flush are by then protected
with fungicide and act as reservoirs for fungicide residues that can be
distributed to other new leaves during subsequent rains. Fruit gradually
become less susceptible to scab infection, and hot weather may
decrease the viability of apple scab conidia produced during this post-bloom
period.
An early spring such as we appear to be having this year often produced
An extended period of high-risk period for apple scab because there are
usually more days between bud-break and petal fall. That means more days
when rain can wash off fungicide residues and potentially more days for
primary infections to become established and produce conidia before trees
reach petal fall.
The Bottom Line : Consider all of the risk factors when
deciding when and what to spray for apple scab. Controlling apple scab at
minimal cost is still as much an art as it is a science. Eliminating one
or two early-season scab sprays in low-inoculum orchards can significantly
reduce costs, but allowing scab to become established before bloom can also
be costly, especially in a year with an early spring.
Editor's Note: Due to the unusual warm weather spell in the end of March,
we had a scab infection period April 1. The following note from Volume 6,
No. 1 of the Healthy Fruit UMass Newsletter for April 1, 1998 addresses
this matter in the article.
Scab risk comes down to four basic components:
* the amount of mature inoculum;
* the susceptibility of the tissue to scab;
* the size of the tissue;
We can use these risk factors to determine whether or not to make a fungicide
application to control scab. Let's look at where we are relative to these
factors.
First, the proportion of inoculum which is already fully mature and ready
to release is high. I would estimate it is easily over the threshold for
the beginning of the season in most areas, based on the direct observations
and the temperature model for scab maturity. Of course, most commercial
blocks should be in reasonably good shape in terms of the amount of overwintering
scab. But where there is scab inoculum, a lot of it is ready to release
with the next wetting period, probably today.
Second, the new, rapidly growing tissue is very susceptible to scab. It
will remain that way for the next couple of weeks.
Third, there isn't much tissue out, compared to what there will be in around
bloom and petal fall. So there isn't a lot of target out there for the scab
spores to hit.
Dave Gadoury, Bob Seem, Arne Stendvand and Stuart Falk of Cornell's Geneva
Ag. Expt. Station have done all the math for us for an average year, and
checked it against real happenings. They took individual risks based on
each of the three factors, amount of inoculum, susceptibility of tissue
to scab, and the size of the target tissue, and combined them to get a picture
of overall scab risk in a typical season. The heaviest risk usually comes
during a two week period from early tight cluster through bloom.
Primary scab season has started. Right now, the risk of scab in a typical
orchard is low to moderate in Connecticut and Massachusetts. With today's
(April 1) rain, we will go have the first infection period of the season.
It will need to be treated.
Rovral may not be used later than petal fall on peaches. Also,
no more than three applications can be applied per season. Rovral may still
be used up to seven days preharvest on nectarines, plums, prunes, apricots
and cherries. For these crops, four applications are allowed per season.
Editor's Note: Rovral flowable and wettable powder formulations received
label changes to peaches and stone fruits in late April of 1997. New product
labeling with the above changes began in late May or last year. There was
a tolerance change to peaches but no product recall. Existing inventories
of Rovral product with old labeling can still be used while supplies last.
In conference with DEP it is suggested to use old product up now on peaches
and do not store or save. We do not know what future restrictions for use
on peaches may occur.
This guide should be available by the end of April. We will let you know
as soon as we receive them.
(Art Agnello, Entomology, Geneva)
For the first time in a long time, European red mite management has finally
reached the point of not having to be an endless game of catch-up. Although
we call the approach we are promoting resistance management, the more appropriate
term would really be susceptibility management, and the apple (and pear)
industry is now in a position to show its ability to exercise some responsible
stewardship of the tools available to this end. Perhaps the single most
useful piece of advice we can offer to apple growers looking to preserve
the effectiveness of the miticides available to
them is: Rotate! That is, whatever mite control program was used last year,
and regardless of even how well it worked, wise resistance management practice
dictates a change to a different one in 1998. The rationale behind this
advice is that the time to manage pesticide resistance is before it starts
to show up, and the options that now exist for mite control make this a
practical, if somewhat controversial strategy for ERM.
Apollo and Savey should be regarded as essentially the same material for
purposes of resistance development, considering the well-known incidences
of cross-resistance between these two products in the world fruit industry.
There is not yet any evidence of ERM resistance to Agri-Mek, but there is
also no reason to expect it not to occur at some time in the future. Nevertheless,
with a number of early season products to choose from, it's not difficult
to formulate a few different rotation programs to begin
using, and most growers have already used one of these rotations last
season.
One such program could be a prebloom spray of Savey or Apollo, and then
a summer rescue application of Pyramite, Carzol or Kelthane, if needed.
Admittedly, some of these summer materials have certain limitations, but
the effectiveness of the early season products should work to minimize the
severity of any late-season outbreaks that do occur. A possible 2nd-year
rotation would be to use Agri-Mek at (or immediately after) petal fall;
an
oil spray before bloom could be elected, but this has actually proven not
to be necessary in several field trials we have conducted with Agri-Mek,
which has provided season-long control with a single well-timed
application. If a summer rescue treatment is needed, rotate among the three
products available for this use. In the 3rd year a return to Apollo or Savey
could be recommended, etc. Implicit in the provisional need for a rescue
treatment is the practicality of once again taking leaf samples in the summer
to determine how close to threshold (remember that concept?) the population
is. The presence/absence charts for this simple exercise can be found on
pp. 98-100 of the 1998 Recommends.
Ideally, these rotation programs should be used on a farmwide basis, or
on
as large a scale as is practical; although we have no evidence to indicate
that mites from one block will "contaminate" (for resistance purposes)
an adjacent block that has received a different miticide program, the chances
of such an event occurring are obviously less if the entire farm is treated
with the same program during the season.
The Labor Committee of the Connecticut General Assembly has approved
and sent to the House & Senate floors a bill, HB 5368 that would raise
the state minimum wage from the current $5.18/hour to $6.30/hour. This increase
would put Connecticut's competitiveness in the economy way out of line with
neighboring states. Also, our state minimum wage has always been pegged
to the federal minimum wage (kept at three cents more than the federal).
The minimum wage is not, nor has it ever been, a living wage. Jumping the
wage up a full $1.12 in one swoop will have a devastating effect on hiring
entry-level workers, and will suddenly put pressure on employers to raise
all other employee wages -- whether justified or not. A bill that would
mandate overtime pay (time-and-a-half) for all workers on Sundays and holidays
in companies that have retail facilities of 3,500 square feet or more. -
Contact Your State Legislator Today!
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