July 20, 2007

Docket Title: Citrus Canker; Movement of Fruit from Quarantine Areas

Docket Type: Rule

ID: APHIS-2007-0022-0001

Subject: Comments

If one reads the above referenced Document by its self it may seem to be
a reasonable body of work, if overly cautious. If it is read as the
third part, and the conclusion to several years of APHIS work, including
its "Risk Management Analysis" (June, 2007) and the "Evaluation of
asymptomatic citrus fruit as a pathway for the introduction of citrus
canker disease" Revision 2 April, 2007 the shortcoming in the rule
become glaring.

I commend the USDA for dropping the requirement for grove inspection
prior to harvest. That step was a waste of resources that could be
better utilized elsewhere. The fact that a grove is inspected does not
mean that canker or the bacteria associated with canker is not present.
All that occurred was that at the time of inspection there was no
visible sign of canker that the inspectors could discern. It will also
make harvesting easier for the grower and shipper since they will not
have to schedule an inspection or worry as the whether a previous
inspection is still valid and current at the time of the proposed
harvest

Amending the regulations to allow regulated articles that otherwise
would not meet the eligibility requirements for interstate movement to
be allowed to be moved directly to a port for export could have some
benefit to shippers in Florida and is a worthwhile change.

The proposed rule does not vary much from the current system for
shipping citrus fruit in Florida under quarantine with the exception of
the rescinded grove inspections and the stricter USDA packinghouse
inspections. The definition of the term Lot as described by the USDA and
the definition which may be currently utilized by the industry and that
which is used by the FDA&CS/DFVI may be somewhat at odds. Under the
proposed rule a lot will be defined as "The inspection unit for fruit
composed of a single variety of fruit that has passed through the entire
packing process in a single continuous run not to exceed a single work
day (i.e., a run started one day and completed the next day is
considered two lots)". Does this mean that the fruit from several
growers will be considered one lot by the USDA if the fruit is of the
same variety and packed on the same day? Does it mean that if
symptomatic fruit is found packed in this newly defined USDA lot then
all the growers for that variety packed on that day will suffer the
consequences even if the fruit from their grove was asymptomatic?
Perhaps before the USDA defines a Lot it should allow the packinghouses
to define what they consider a Lot and utilized that definition in the
inspection and record keeping process.

From this commenter's standpoint the proposed Rule changes are almost
much ado about nothing, which goes back to the earlier comments about
the shortcomings in this Rule. This document should not be considered a
Rule but rather a minor amendment to an existing Rule. The true Rule
should come about when USDA/APHIS is ready to publish a final Rule
allowing for the shipment of commercially treated citrus fruit to all
States and Countries under certain guidelines established in a Federal
Quarantine. In the two documents referred to previously in these
comments APHIS has made the determination with "almost" complete
certainty that asymptomatic citrus fruit that has been commercially
handled is not a pathway for the spread of citrus canker. On page one of
the "Evaluation of asymptomatic citrus fruit as a pathway for the
introduction of citrus canker disease" April, 2007, it is stated, "The
evaluation concludes that asymptomatic, commercially produced citrus
fruit, treated with disinfectant dips, and subject to other mitigations,
is not epidemiologically significant as a pathway for the introduction
of citrus canker." The next paragraph on page one, Executive Summary,
states, "In the event that infected fruit enter a canker-free area with
susceptible hosts, the establishment of the disease via this pathway
would require particular environmental and physiological conditions at
the precise time that an infected fruit was placed in close proximity to
a susceptible host. The combination of conditions necessary for
introduction are so difficult to achieve that the likelihood of such
occurrence is greater than the baseline exposure represented by
unregulated pathways. The conclusions of the evaluation are reinforced
by a strong record of empirical date from experience and interceptions."

In reading both reports published by the USDA/APHIS leading up to this
proposed Rule change several important factors are made very clear and
suggest that this Rule change does not begin to do enough. Paraphrasing
of the two reports issued by APHIS should give the USDA and the
Regulators an understanding of why it is felt that the proposed Rule
change does very little for the Florida Industry in light of the
empirical and scientific data available:

1.  Commercially handled asymptomatic citrus fruit is not a vector for
    the spread of citrus canker.

2.  The vast majority of symptomatic fruit will be removed in the
    grading and packing process.

3.  The canker bacteria does not survive for long periods of time on
    symptomatic fruit that has been sanitized, washed, heated, waxed,
    and dried.

4.  Canker enters a plant through wounds and it is unlikely that
    susceptible naturally occurring wounds would be available; therefore
    a very limited window of opportunity exists.

5.  California and Arizona do not have climates conducive to canker
    infestations because of the lack of rain and temperature in their
    rainy season.

6.  "There is no evidence that either infected fruit with lesions or
    asymptomatic fruit are epidemiologically significant with respect to
    the initiation of new infections." (Jetter et al., 2000; Cannteros,
    2004, Anonymous, 2005a; Anonymous, 2005b).

7.  Treatments of sodium hypochlorite and SOPP are effective in
    eliminating epiphytic populations of citrus canker bacteria.

8.  "Asymptomatic fruit naturally and artificially contaminated with
    canker bacteria subjected to the above treatments eliminated 99.5%
    of epiphytic canker bacteria. Whereas there was not 100% destruction
    of the bacteria, it was not possible to culture the surviving
    bacteria on susceptible leaf tissue." (Verdier et al., unpublished).

9.  Epiphytic populations of canker bacteria that might survive
    post-harvest treatment would not be expected to survive on the
    surface of fruit for longer than 72 hours and would not be expected
    to multiply. (Goto, 1969, Timmer et al., 1991).

10. Argentina has in pace a protocol that allows for the shipment of
    fruit from groves in a quarantine area and has not had any problems
    with the spread of canker.

11. Large quantities of fresh citrus shipped for many years from regions
    with canker have not resulted in any known outbreaks or infestations
    of canker.

12. "There are no accounts in the published literature indicating that
    fresh citrus fruit or seeds can serve as pathway for the
    dissemination of Xac. Long distance dissemination of the pathogen
    occurs primarily through the movement of propagative material, such
    as budwood and rootstock seedlings or budded trees from nurseries."
    (CABI/EPPO 1997).

13. For years Florida shipped fruit during canker outbreaks to other
    citrus producing States with no outbreaks of canker resulting from
    these shipments.

14. APHIS concludes that the absence of reports of citrus canker disease
    outbreaks linked to commercial fresh fruit combined with multiple
    reports of outbreaks due to propagative material as important
    evidence. This evidence is not sufficient to prove that fruit cannot
    possibly serve as a pathway for the introduction of Xac. This
    evidence is sufficient to conclude that if such a pathway exists at
    all, it is rarely successful in natural environments compared to
    other pathways of Xac introduction.

The points listed above are just a few of the many bits of scientific
and empirical data collected and analyzed by the scientists at APHIS and
elsewhere concerning citrus canker and the ability of the disease to be
spread by commercially handled symptomatic and asymptomatic fruit. A
thorough reading of this information would lead to the conclusion that
fresh fruit, commercially handled, would not aid in the spread of citrus
canker. Canker is a disease spread by wind and rain for the most part
and commercial fruit is not a pathway. The introduction of contaminated
plant material will be the origin of any additional or future canker
outbreaks.

The Revision2, April 2007 shows how far fetched is the notion of
spreading canker with commercially handled fruit when it starts out on
page eleven by saying," Assuming that it may be possible for fruit to
serve as a pathway" and then lays out an improbable scenario of what it
would take to do so. The five steps listed on page eleven are not going
to happen, at least not all of them or perhaps any of them.

I feel that the USDA should not be overly concerned with the impact of
the proposed Rule change but should be looking at how to work with the
Florida Industry and the rest of the country to help get Florida beyond
its limited shipping status. If there are valid gaps in the science then
USDA should be looking to fill those gaps. If there are procedural
issues the USDA should be addressing them. These answers should go
toward the promulgation of a final Rule allowing for the shipment
world-wide of the properly processed commercial fruit.

The various local, State and Federal agencies charged with plant
protection need to be mindful of the fact that uncontrolled,
non-sanitized fruit with plant material attached poses the threat to the
health and wellbeing of the citrus industries they are responsible to,
not commercially handled fruit. With that in mind these agencies should
welcome a viable shipping method for their own benefit.

Submitted by,

John A. Scotto

P.O. Box 1017

Ft. Pierce, Fl 34954

772 464-0300