Document ID: EPA-HQ-OPP-2006-0766-0049
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2011-11-09T05:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF           

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

DATE:		8/21/2000

SUBJECT:	Review of Request for Residue Data Developed for Almonds to be
Translatable to Pistachios for Establishing Tolerances. DP Barcode
D212794.

      .

FROM:	Bernard A. Schneider, Ph.D., Plant Physiologist

Chemistry and Exposure Branch 1

Health Effects Division (7509C)

THRU:	William Hazel, PhD, Chairperson CHEMSAC

Health Effects Division (7509C)

TO:		Hoyt Jamerson, Product Manager

MUERIB

Registration Division (7505C)

Dr. Keith W. Dorschner, Coordinator, Interregional Research Project No.
4 (IR-4) submitted a  proposal to CHEMSAC on April 24, 2000 on behalf of
the IR-4, the California Pistachio Commission, and the University of
California to request that residue data developed for almond is
translatable to pistachio and will be used to establish tolerances for
pistachio.     

Background:

On March 4, 1997 (see attached report of B.A. Schneider, D212794, CBTS#
15228), HED recommended that pistachios be included as a member of the
Tree Nuts Crop Group (40CFR§180.41).  It was also determined that the
representative commodities almond and pecan for the Tree Nuts Group
adequately represent the Crop Group.  This policy paper was sent to
Registration Division for implementation by publishing an amendment to
the Crop Group final rule in the Federal Register.  However, due to FQPA
priorities, the Agency has no plans to amend the Crop Group Regulations
at this time, but the Agency is allowing petitioners to request
tolerances for pistachio based on residue data submitted for the Tree
Nut Crop Group.  Until the Federal Register Notice is issued revising
the Crop Group Regulation, tolerances for pistachios will be listed
separately from the Crop Group, but the tolerance will be established at
the same level as the Crop Group.   

CONCLUSIONS

1a. The pistachio nutmeat is enclosed in a fleshy hull composed of three
distinct tissue layers which include: an epicarp or outer layer; a
mesocarp or middle layer; and endocarp the hard inner layer or shell.

1b.  The epicarp and the mesocarp combine to form the fleshy hull that
protects the nut.  The endocarp will become the hard nutshell that
protects the edible embryo or nutmeat (RAC). 

1c. it is the hard nutshell enclosed in the protective fleshy hull that
splits or dehisces near harvest, and even though up to 80 % of the nut
shells may be split at harvest, over 97 % are still enclosed and well
protected from surface pesticide residues by the outer intact pericarp
layers at harvest.   

1d. Only 2.4 % of the pistachios had both the outer hull and shell split
at harvest and these are called "early splits".

1e. Early splits are not desirable and 91 to 93 % of the early splits
are currently sorted out by high speed bichromatic sorters after harvest
and discarded during processing because of being poor quality and being
vulnerable to or carriers of aflatoxins. 

1f.  Several research projects are designed to reduce the number of
early splits by improved cultivar development or by developing better
processing and sorting equipment.  A new machine vision bichromatic
sorting system will improve the number of early splits removed to > 99
%. 

2.   Residue trial data and established tolerances comparing pesticide
residue levels in pistachios with other tree nuts have consistently been
similar.

3.   Imported pistachios account for less than 1.0 % of all pistachios
consumed in the U.S., thus early splits appearing from the different
cultivars from these countries would be an extremely insignificant
amount. 

4.   Pistachios share the same weed, nematode, insect and plant disease,
and post harvest 	storage problems that affect the other members of the
Tree Nuts Crop Group. 

5.   Almonds are a better representative commodity than pistachios for
the Tree Nuts Crop Group because almonds have significantly higher
percent hull splitting; more of the developed almond nutmeat is present
during pesticide applications; almonds have a livestock feed item
(hulls); almonds are produced in much larger quantities; and almonds
have a more porous and soft shell.   

6.   Based on similarities of pesticide residue levels, cultural
practices, pomological similarities, production regions, and pest
problems pistachios should be included as a member of the Tree Nuts Crop
Group.

7.   There are no animal feed items associated with pistachios.

RECOMMENDATIONS

Chemistry Branch recommends including the pistachio (Pistacia vera L.)
as a member of the Tree Nuts Crop Group (40CFR§180.41).  All
deficiencies regarding including pistachio nuts in the tree nut crop
group have been resolved.  We expect pesticide residues in the pistachio
nutmeat to be similar to the other nut crops that are members of the
Tree Nut Crop Group, because the outer hull remains’s intact
completely covering and protecting the nutmeat even after the shell has
split.  These early splits are further removed during processing by
automated high speed bichromatic machines and by hand sorting such that
> 99 % of the culls are removed at the packinghouse.  

Common names for pistachios to be added to the Crop Group Index are
`green almond' and `pistacia nut'.  There will be no change to the
representative commodities for the Tree Nut Crop Group.  The
representative commodities are almonds and pecans.

NOTE:  Chemistry Branch would like to thank both IR-4 and Dr. Louise
Ferguson, Extension Pomologist, University of California at Davis and
Mr. Eric Harmon for arranging and collecting weekly samples of in-hull
pistachio during the growing season for us to investigate.  The
resultant observations and data were essential in determining that
pistachios should be a member of the Tree Nuts Crop Group.

Table 2.  Updated Comparison of Established Tolerances for Pistachio and
Tree Nut Crops.   

Pesticide (CFR Citation)	

Pistachio 

Tolerance (ppm)	

Tree Nut Crop 

Tolerance (ppm)

Benomyl [§180.294]	

    0.2 	

 0.2  (nuts) 

Glyphosate [§180.364(a)] 	

    0.2	

 0.2  (nuts)

Azoxystrobin [180.507]	

   0.01	

0.01

Halosulfuron [180.479]                     	   0.05	

0.05

Urea [180.1117]	exempt	

almond, pistachio

Magnesium phosphide  [§180.375]	    0.1	

 0.1  (almonds, filbert, pecans,      	walnut)

Permethrin [§180.378]	    0.1	

 0.05 (almond, filbert, walnut)

Azinphos-methyl [§180.154]	    0.3	

 0.3  (almond, filbert, pecan, walnut)

Carbaryl [§180.169]	    1.0	

 1.0  (almond, filbert, pecan, walnut)

2,4-D [§180.142(b)]	    0.2	

 0.2  (nuts)

Napropamide [§180.328(a)]		

    0.1	

 0.1  (nuts)

Oryzalin [§180.304]	

    0.05	

 0.05 (nuts)

Oxyfluorfen [§180.381]	

    0.05	

 0.05 (tree nuts group (except 	almond hulls) 

Paraquat dichloride [§180.205]	

    0.05	

 0.05 (nuts)

Phosmet [§180.261]	

    0.1	

 0.1  (nuts)

Aluminum phosphide [§180.225]	

    0.1	

 0.1  (almonds, Brazil nuts, walnut)

Methyl bromide (§180.123]	

  200	

 200  (almonds, Brazil nuts, bush nuts, butternuts, cashews, filberts,
hickory nuts, pecans, walnuts)  

	DETAILED CONSIDERATIONS

BACKGROUND:

Chemistry Branch has considered the inclusion of pistachio nuts to the
tree nut crop group four times (memos of F. Griffith, Jr., RCB No. 1057,
9/25/85; R.W. Cook, 2/25/85;  E. Leovey, 4/16/80, and R.B. Perfetti,
10/9/79), and all of these previous requests were rejected by CB
(previously RCB).  All of the outstanding deficiencies regarding
including pistachio nuts in the tree nut crop group have been resolved,
except for CB concerns "that the unsealed husks or shells (splits) found
in pistachio nuts would expose the edible portion to significantly
higher residues than would occur in other tree nuts"  (memo F. Griffith,
Jr., RCB No. 1057, 9/25/85).

The Chemistry Branch had also previously thought that since the
pistachio nut shell splits before harvest, it would be readily exposed
to pesticide applications.  However, literature references indicate (30,
31) that although the pistachio shell splits before harvest, the nutmeat
remains inside an intact hull so it may not be exposed to a pesticide. 
The critical issue with pistachios will be to determine how intact the
outer hull that surrounds the shell and nutmeat remains during the
season from flowering to harvest. 

Since the critical remaining issue was to determine the exposure of the
actual pistachio nutmeat to pesticide applications, Dr. Schneider
arranged with IR-4 (G. Markle), to submit pistachio nuts at weekly
intervals for up to a 6-week period ending at harvest.  These samples
helped CB determine the extent that the outer hull around the actual
nutmeat stays intact and if it could prevent the possibility of direct
pesticide residues to the nutmeat before harvest.  IR-4 arranged for Dr.
Louise Ferguson, Extension Pomologist, University of California at Davis
and Mr. Eric Harmon, student at Fresno working for Dr. Ferguson to
collect from a commercial pistachio orchard approximately one kg of
in-hull pistachios from July until harvest on September 22, 1995.  The
samples were counted for number of hulls split, extent of hull cracking
and dissected to determine if the nut shells were split or open. 
Chemistry Branch would like to thank these researchers for their
cooperation in obtaining and shipping pistachios in various stages of
development for the 6-week period before harvest.  In addition, CB
conducted a comprehensive literature search on pistachio hull splitting
and current research projects in USDA on pistachios.  All of the above
combined data were used to determine the extent that the outer fleshy
hull stays intact even after the inner shell splits. 

In order to understand the pistachio hull and shell splitting and their
influence on potential pesticide residues in the nutmeat, an
understanding of the botanical (pomological) terms that relate to the
fruit or drupe of the pistachio is necessary and will be discussed
below.

POMOLOGICAL FACTORS RELATING TO PISTACHIO HULL SPLITTING: 

Botanically, pistachios and almonds have fruits called drupes.  In the
case of tree nuts, the drupe consists of a single edible seed lying
inside a thin but hard bivalve shell that is surrounded by a fleshy hull
or pericarp.  The pericarp consists of three layers or tissues.  These
three layers of the pericarp are as follows: [1] an epicarp or outer
layer; [2] a mesocarp or middle layer; and [3] endocarp the hard inner
layer (12).  The epicarp and the mesocarp combine to form the fleshy
hull that protects the nut.  The endocarp will become the hard nutshell
that protects the edible embryo or nutmeat (RAC).  In both the pistachio
and the almond the outer skin of the fleshy hull is the epicarp, while
the bottom layer of the fleshy hull is the mesocarp, and these two
layers help protect the nutmeat that is also encased in the hard shell
(endocarp) from pest problems.  It is the hard nutshell of the pistachio
enclosed in the protective fleshy hull that splits or dehisces near
harvest.   

After pollination and fertilization (April), the ovary walls or pericarp
enlarges rapidly in length and diameter and within six to eight weeks
(middle May) attains its full size (7).  However, while the shell has
become full-sized and hard it is still nearly empty.  The embryo of the
pistachio, which is in the shell, begins rapid expansion in late June
and grows rapidly after this stage, maturing within 16 weeks or
approximately 140 days after pollination (3, 4, 5, and 15).  As the
fruit matures, the fleshy hull becomes soft and the endocarp layer
partly separates from the shell.  Inside the hull, the shell turns
opaque white in color and splits (or dehisces) longitudinally as a
normal part of abscission because of the seed (nutmeat) enlarging and
exposing the purple-red seed coat (last week of July thru August) but at
this growth stage the outer hull still remains intact (8).  This normal
splitting of the nutshell is a highly desirable characteristic that
plant breeders utilize in their selections, and is also favored by
consumers because of the ease in hand-shelling the nut (8, 29, 30, 32). 
Nonsplit shells (21) may range up to 20% of the harvest and are sorted
out during processing and sold as broken nutmeats.  Currently, hulls are
removed completely by abrasive peeling machines, followed by separation
of split from unsplit shells by a water flotation method and/or by air
jetting.  Nuts that don't split are undersized, stained, and not
desirable for the consumer.  In addition, early splitting is a problem
since it encourages aflatoxin and insect contamination/damage as well as
staining to the shell that makes a low quality nut.  Approximately 1.5
to 2.5% of the nuts are unmarketable due to early splitting or empty
shells (6, 14, 17, 21, and 22).  Harvesting is gauged by the change in
the color of the outer pericarp layer from translucent pinkish-green to
opaque as well as a softening and loosening of the hull from the shell
(8).  The fruit or drupe will not abscise or drop from the tree at this
time, but the hulls or pericarp (epicarp + mesocarp layers) will
continue to dry and shrivel for several weeks.  

Early splitting of hulls exposing the nut is not a desirable
characteristic, and currently there are several research projects on
pistachios designed to either select for cultivars that produce less
early splits by eliminating from breeding programs cultivars that
exhibit this predisposing trait [7, 10, 11, 13, 14, 18, 29, 30, 32] or
to develop techniques to sort out these early split nuts while
processing the harvested nuts [7, 14, 21, 22, 29].  Current processing
techniques used to sort out pistachios by automated high speed
bichromatic sorters that will sort up to 144,000 pistachios/hour and
combined with hand sorting for culls will remove 91 to 93 % of the early
splits (33).  A newly developed "machine vision" computerized system
bichromatic sorter has been developed and can sort out > 99 % of the
early splits (24, 25).     

ANALYSIS OF PISTACHIO HULL SPLITTING:

Chemistry Branch received eight separate shipments of approximately 1 kg
in-hull pistachios from Dr. Louise Ferguson, Extension Pomologist and
Mr. Eric Harmon at the University of California, Davis that were sampled
from July until harvest on September 22, 1995.  The samples were
collected manually and at random on 9/21/95 from a commercial pistachio
orchard using the cultivar `Kerman' in Kern County, Parlier, CA.  Over
((% of the pistachios harvested in the U.S. are the `Kerman' cultivar. 
The samples were placed in plastic bags and kept refrigerated until
shipment to Dr. B. Schneider's home in Columbia, Maryland where they
were stored in the refrigerator and analyzed within 48 hours after
receipt.  The hulls at harvest were light greenish-yellow in color and
could be easily removed from the nut shell by rubbing between the thumb
and forefinger.  Over 2100 in-hulled pistachios were individually
counted as part of this study.  The samples were counted for number of
hulls that split, extent of hull [pericarp and or mesocarp] cracking,
color of hull, and were then dissected to determine if the nut shells
were split or open, and the data is summarized in Table 1.   For a
discussion of the three tissue layers that comprise the hull see the
previous section entitled: "Pomological Factors Comparing Pistachios and
Other Members of the Tree Nuts Crop Group." 

The splitting of the hulls that occurred is different for the two tissue
layers [pericarp and mesocarp] that surround the shell [endocarp].  The
outer layer of the hull or pericarp splitting started at 30 days before
harvest and was only 2.2% at that time but increased up to 50 % at
harvest.  In contrast, the inner or mesocarp layer of the hull that also
feels leathery was completely intact until 14 days before harvest (1.1
%) splits with only 2.4 % splits at harvest.  Therefore, only 2.4 % of
the pistachio nuts that are split would be exposed to any surface
pesticide residues.  However, CB considers the 2.4 % of the pistachios
that have the hulls and nut shells split at the same time an
overestimation for several reasons.   First, these early split nuts are
usually sorted out after harvest during processing because poor quality
nuts are removed and discarded before they reach commercial use [21, 22,
and 23].  Newer machine vision sorting technology will sort out > 99 %
of the early splits in the processing line.  Also, these split nuts are
mechanically separated from normal pistachios because they are
vulnerable to or carriers of the carcinogenic aflatoxin mold
[Aspergillus flavus] (4, 28, 29).  Another botanical related factor that
protects the nutmeat in shells that have split from pesticide residues
is the fact that the outer hull begins to split at the stem end, while
the open nut shell faces downward in the opposite direction and is still
fully protected by the leathery inner layer or mesocarp.  So, when the
shell is split open the hull is still intact, except in one to four % of
the cases where the hulls adhere tightly to the shell and split along
with the shell.  These are called "early splits".  Plant breeders are
continuing to develop improved cultivars that will have even less early
split nuts before harvest [32].  In addition, over 97.6 % of the
pistachio nut shells that are split were still protected by an intact
inner hull layer or mesocarp.  Our research numbers are very close to
those reported in the scientific literature and in USDA current research
project reports which showed that 1.0 to 4.0 % of pistachios are
considered to be "early splits" in which the hull splits along with the
shell [10, 21, and 29].    

Table 1. Determination of Pistachio Hull Splitting From 53 Days Before
Until Harvest.      (7/31 to 9/22/95). 

Days Before Harvest *	

Sample Size (number of nuts counted)	

Nut Shell Open (Splits) [%]**	

Hull Splits (%) 

	

Pericarp (outer layer) 	

Mesocarp (inner layer)

53	

272	

 0	

   0	

   0

43	

232	

 0	

   0	

  0

36	

235	

 0	

   0	

  0

30	

229	

50	

   2.2	

  0

22	

251	

50	

   8.0	

  0

14	

270	

52	

 13.0	

 1.1

7	

450	

58	

 42.0	

 2.0

 0	

250	

80	

 50.0	

 2.4

*   The dates of sample collection are as follows: 7/31; 8/7; 8/14;
8/22; 8/30; 9/5; 9/12; and 9/22/95.

**  The number of nut shells that are open was from the hull (split)
samples.  Nut shells counted in the unsplit hull samples averaged 40%
shell split at the last 	sampling date.     

By this independent study, Chemistry Branch has confirmed that the
shells of pistachio nuts split naturally in the orchard [< 80 %] prior
to harvest, but the hull stays intact, covering and protecting the
kernel from an invasion by molds, insects, and nonsystemic pesticides. 
Early split hulls were in the range of < 2.4 % by harvest, and none
occurred before 14 days before harvest.  As the pistachio drupe (fruit)
matures the outer hull (epicarp + mesocarp) loosens from the shell
(endocarp) that covers the seed (nutmeat) until the shell splits.  The
hull still remains’s intact completely covering and protecting the
shell even after it has split.  The early splits are usually sorted out
prior to the pistachios entering commerce and in the future improved
sorting techniques will remove > 99 % of the early splits.

Therefore, the deficiency regarding CB concerns "that the unsealed husks
or shells (splits) found in pistachio nuts would expose the edible
portion to significantly higher residue higher pesticide residues than
would occur in other tree nuts” (memo F. Griffith, Jr., RCB No. 1057,
9/25/85) is resolved.  We expect pesticide residues in the pistachio
nutmeat should be similar to the other nut crops that are members of the
Tree Nut Crop Group.  For a discussion comparing pesticide residues in
the tree nuts, see the next section of this report entitled:
"Comparisons of Residue Levels in the Tree Nut Crops".   

COMPARISONS OF RESIDUE LEVELS IN THE TREE NUT CROPS

Over the years tolerances have been established for pesticides on
almonds; pecans; pistachios; nuts; nutmeat; and the tree nut crop group
(40CFR§180).  There are 15 established tolerances for pesticides on
pistachios that can be compared with those registered on similar
pesticides for other tree nuts (Table 2).  In all cases except for
permethrin, the established tolerances are identical.  Even with
permethrin [§180.378], the tolerance of 0.1 ppm established on a
pistachio is well within the Crop Group limit of 5X for the other tree
nuts that are established at 0.05 ppm.    

Table 2.  Comparison of Established Tolerances for Pistachio and Tree
Nut Crops.   

Pesticide (CFR Citation)	

Pistachio 

Tolerance (ppm)	

Tree Nut Crop 

Tolerance (ppm)

Benomyl [§180.294]	

    0.2 	

 0.2  (nuts) 

Glyphosate [§180.364(a)] 	

    0.2	

 0.2  (nuts)

Magnesium phosphide  [§180.375]	

    0.1	

 0.1  (almonds, filbert, pecans,      	walnut)

Permethrin [§180.378]	

    0.1	

 0.05 (almond, filbert, walnut)

Azinphos-methyl [§180.154]	

    0.3	

 0.3  (almond, filbert, pecan, walnut)

Carbaryl [§180.169]	

    1.0	

 1.0  (almond, filbert, pecan, walnut)

2,4-D [§180.142(b)]	

    0.2	

 0.2  (nuts)

Napropamide [§180.328(a)]		

    0.1	

 0.1  (nuts)

Oryzalin [§180.304]	

    0.05	

 0.05 (nuts)

Oxadiazon [§180.304]	

    0.05	

 0.05 (Brazil nuts, bush nuts,  	butternuts, cashews, chestnuts,
filbert, hickory nuts, macadamia nuts, pecans, walnuts

Oxyfluorfen [§180.381]	

    0.05	

 0.05 (tree nuts group (except 	almond hulls) 

Paraquat [§180.205]	

    0.05	

 0.05 (nuts)

Phosmet [§180.261]	

    0.1	

 0.1  (nuts)

Aluminum phosphide [§180.225]	

    0.1	

 0.1  (almonds, Brazil nuts, walnut)

Inorganic bromides (§180.123]	

  200	

 200  (almonds, Brazil nuts, bush nuts, butternuts, cashews, filberts,
hickory nuts, pecans, walnuts)  

IR-4 also submitted comparative field residue data for use of
azinphos-methyl (IR-4 and Miles Agriculture Division) and carbaryl
(Rhone-Poulenc) on various tree nuts and pistachios that were previously
reviewed by CB to establish the tolerance levels for these pesticides. 
Tolerances for azinphos-methyl [§180.154] were established at 0.3 ppm
for pistachio, almond, filbert, pecan, and walnut; while tolerances for
carbaryl [§180.169] were established at 1.0 ppm for pistachio, almond,
filbert, pecan, and walnut (Table 2). 

Therefore based on residue data used to establish tolerances for use of
15 pesticides in/on pistachios and other tree nuts, CB concludes that
residues from pistachios are similar to those found on all other members
of the Tree Nut Crop Group. 

EVALUATION OF REPRESENTATIVE COMMODITIES FOR THE TREE NUTS CROP GROUP:

The current representative commodities for the Tree Nuts Crop Group are
almond and pecan.  Botanically, both pistachios and almonds have fruits
called drupes.  In the case of tree nuts, the drupe consists of a single
edible seed lying inside a thin but hard bivalve shell that is
surrounded by a fleshy hull or pericarp.   Since CB is recommending to
include pistachios as a member of the Tree Nuts Crop Group, it also
investigated whether pistachios should replace almonds as the
representative commodity.  Pistachios are not considered a replacement
for pecans because of the relatively limited geographical production
area for pistachios, whereas almonds and pistachios are grown in the
same region.    

Almonds are still considered to be a better representative commodity
than pistachios for several reasons: first, the nutmeat and shell
develop simultaneously in almonds (Feb-mid-June) so that any pesticides
that are systemic and applied to the foliage during this time may be
translocated to the nutmeat.  Pistachios on the other hand have the
shell growing during this stage and increasing in diameter, but the
embryo and nutmeat do not begin their growth until July 1.  Therefore,
the nutmeat in pistachios is not present from pollination (mid-April
through June) in contrast to almonds (20).  Secondly, differences in
maturity of the hulls make almonds a worst case for estimating pesticide
residues.  In almonds, the outer hull readily splits, but the nut shell
does not, whereas in pistachios the outer hull stays almost completely
intact (for more details see analysis of pistachio hull splitting
section) while the nutshell begins splitting (dehiscing) from late
August until September 15.  One of the ways to determine the
physiological maturity of the pistachio is by the ease in which the hull
(epicarp + mesocarp) separates from the nut shell.  Pistachios must be
harvested before the hull degenerates so that the nutshells will not be
stained (7).  Therefore, in pistachios the outer hull stays intact
through harvest preventing residue accumulation on the nutmeat, whereas
the almonds split from their fleshy hulls at maturity which allows the
nut to drop to the ground, and some cultivars such as `Nonpareil' can
range from 18 to 82 % splits.  The almond shell is also more porous or
papery (genetically soft shelled) and softer than the pistachio shell
(2, 16, 19).  

    

While the scientific literature (10, 30, 32) and our own analysis
indicate that from < 1% to 4% of the pistachios have early split nuts
and hulls, these are later removed as culls during processing to remove
the stained nuts to prevent aflatoxin contamination.  Pistachios are the
only tree nut that has open split shells at harvest, but > 97 % of these
are protected by an intact hull.  Pistachios also have less opportunity
for pesticide residue accumulation in the nutmeat because foliar
translocation to the developing nutmeat does not occur when most
pesticide applications 

to control insect and plant diseases are made, and the nutmeats at
harvest are still protected by 

the outer hull.  Imported pistachios during 1993-94 accounted for < 1.0
% of the total pistachios consumed in the U.S. (9).  Approximately, 81.5
% are imported from Turkey.  Therefore, any early split pistachios that
may be imported would be an insignificant component of the diet. 

Pest problems in almonds and pistachios are similar [see section on
comparison of pest problems in pistachio and other tree nut orchards]. 
Only almond hulls are a significant livestock feed item in the tree nut
crops.  Pecans, the other tree nut crop group representative commodity,
have a much wider geographical distribution than either almonds or
pistachios.  Therefore, based on almonds having a livestock feed item;
more percent hull splitting; more of the developed nutmeat present
during pesticide applications; the same geographical region; and a more
porous or papery shell, Chemistry Branch does not recommend to change
the present representative commodities of the Tree Nut Crop Group.     

COMPARISON OF PEST PROBLEMS IN PISTACHIO AND OTHER TREE NUT ORCHARDS:

Pistachios share the same weed, nematode, insect and plant disease, and
post harvest storage problems that affect the other members of the Tree
Nuts Crop Group [1, 7, 8, 10, 14, 17, 18, 26, 27].  Pests of almonds
such as the naval orangeworm (Ameyelois transitella) often invade
pistachio orchards [1, 26].

LIVESTOCK FEED ITEMS:

There are no animal feed items associated with pistachios.  The
representative commodities for Crop Group 14: Tree Nuts are almonds and
pecans, and only almond hulls are a livestock feed item in this Crop
Group.   

HARMONIZATION WITH CODEX:

CODEX places pistachio in its Crop Group 22: Tree Nuts.  Addition of the
pistachio to U.S. Crop Group 14: Tree Nuts will harmonize the two Crop
Group systems with regard to pistachios.  

REFERENCES:

 1. Andrews, K.L. and M.M. Barnes. 1982.  Invasion of Pistachio Orchards
by Naval Orangeworm Moths from Almond Orchards. Environmental Entomology
11:278-279.

 2. Campbell, B. 1995. Breeding for Resistance to Aflatoxin
Contamination in Almond. Univ. CA. Project Report # 0500-00029-026-00D.
USDA Current Research Information Service.

 3. Crane, J.C. and M. Bradley, and M. Nelson. 1971. Growth of Seeded
and Seedless Pistachio Nuts.  J. American Society for Horticultural
Science 96:78-80.

 4. Crane, J.C. and I.M. Al-Shalam. 1974. Physical and Chemical Changes
Associated With Growth of the Pistachio Nuts.  J. American Society for
Horticultural Science 99(1):87-89.

 5. Crane, J.C. 1978. Quality of Pistachio Nuts As Affected By Time of
Harvest. J. American Society for Horticultural Science 103(3):332-333.

 6. Crane, J.C. and B.T. Iwakiri. 1982. Shell Dehiscence in Pistachio.
HortScience 17(5):797-798.   

 7. Crane, J.C. 1983. Pistachio Production Problems. Fruit Varieties
Journal 38(3):74-85.

 8. Crane, J.C. and J. Maranto. 1988. Pistachio Production. 15 pp.
University of California Cooperative Extension Publication 2279.   

 9. Dialog/Data-Star. 1997. Tradstat Plus Import/Export Database. Data
search conducted 2/28/97. 

10. Doster, M.A. and T.J. Michailides. 1994. Aspergillus Molds and
Aflatoxin in Pistachio Nuts in California. Phytopath. 84:583-590. 

11. Doster, M.A. and T.J. Michailides. 1995. The Relationship Between
Date of Hull Splitting and Decay of Pistachio Nuts by Aspergillus
Species.  Plant Disease 79 (8): 766-769. 

12. Ferguson, L., B. Beede, and G. Weinberger. 1995. Inclusion of
Pistachios in the Established Tree Nut Crop Group: Pomological Evidence.
Pp. 20-25 In George M. Markle, Associate Director, Interregional
Research Project No. 4 (IR-4) [D212794]. 

13. Goodman, N., T.J. Michailides, and M.A. Doster. 1995.  Field Studies
to Control Aflatoxin Production in the Field. Univ. CA. Project Report #
0500-00029-010-01S. USDA Current Research Information Service.

14. Kadar, A.A. 1995. Maturation, Harvesting, and Nut Quality of
Pistachios. Department of Pomology, University of California. 6 pp.

15. Maggs, D.H. 1986. An Introduction to Pistachio Growing in Australia.
   Commonwealth Scientific and Industrial Research Organization,
Australia. 36 pp. 

16. Magness, J.R., G.M. Markle, and C.C. Compton. 1971. Food and Feed
Crops of the United States. New Jersey Agricultural Experiment Station
College of Agriculture and Environment Science. Rutgers University
Interregional Research Project IR-4. IR Bulletin No. 1., Pp. 114-115. 

17. Maranto, J. and J.C. Crane. 1982. Pistachio Production. University
of California Division of Agricultural Sciences Leaflet 2279. 18pp.

18. Michailides, T.J. 1989. The `Achilles Heel' of Pistachio Fruit.
Calif. Agri. 43(5): 10-11.

19. Micke, W.C. and N. F. Sommer. 1978. Almond Orchard Management.      
   University of California Cooperative Extension Publication 4029. 

20. Nevo, A., E. Werker, and R. Ben-Sasson. 1974. The Problem of
Indehiscence of Pistachio (Pistacia vera L.) Fruit. Israel J. Botany
23:1-13.   

21. Pearson, T.C., D.C. Slaughter, and H.E. Studer. 1993. Separating
"Early-splits" from "Normal" Pistachio Nuts for Removal of Nuts
Contaminated on the Tree With Aflatoxin. Papers American Society of
Agricultural Engineers Paper# 936050. 11 pp.    

22. Pearson, T.C., D.C. Slaughter, and H.E. Studer. 1994. Physical
Properties of Pistachio Nuts. Transactions of the American Society of
Agricultural Engineers 37(3): 913-918.

23. Pearson, T.C., D.C. Slaughter, and H.E. Studer. 1996. Hull Adhesion 
   Characteristics of Early-split and Normal Pistachio Nuts. Applied 
Engineering in Agriculture 12(2): 219-221.

24. Pearson, T.C. and D. Slaughter. 1996. Machine Vision Detection of 
Early Split Pistachio Nuts. Transactions of the American Society of
Agricultural Engineers 39(3): 1203-1207. 

25. Pearson, T.C. and T. Schatzki. 1997. Superior Sorter Selects
Stain-Free Nuts. Agricultural Research 45(1):18. 

26. Rice, R.E., W.J. Bently, and R.H. Beede. 1988. Insect and Mite Pests
of Pistachios in California. University of California. Division of
Agriculture and Natural Resources. Publication 21452. 26 pp.

27. Rosengarten, Jr., F. 1984. The Book of Edible Nuts. Pistachios. 
Pp.197-213.  First Ed. Walter & Co, Publ. NY.

28. Schatzki, T., D. Slaughter, and H. Studer. 1993. Separating
Early-Split from Normal Pistachio Nuts for Removal of Nuts Contaminated
With Aflatoxin. Univ. CA. Project Report # 5325-42000-015-0IS. USDA
Current Research Information Service.

29. Schatzki, T., P. Keagy, and R. Sayre. 1995. Detection of Aflatoxin
Contamination in Human Food by Imaging Technique. Univ. CA. Project
Report # 5325-42000-015-00D. USDA Current Research Information Service.

30. Sommer, N.F., J.R. Buchanan, and R.J. Fortlage. 1986. Relation of
Early Splitting and Tattering of Pistachio Nuts to Aflatoxin in the
Orchard. Phytopathology 76:692-694.

31. Sommer, N.F. 1994. Genetic Variation in the Resistance of Various
Cultivars of Tree Nut to Aspergillus flavus, Univ. CA. Project Report
#0500-00029-006-01S. USDA Current Research Information Service.

  

32. Sommer, N.F. 1995. Genetic Variation in the Resistance of Various
Cultivars of Tree Nut to Aspergillus flavus, Univ. CA. Project Report 
#0500-00029-006-01S. USDA Current Research Information Service.

  

33. Weinberger, G. 1997. Personal Communication with Dr. B.A. Schneider,
February 10. Research Coordinator. California Pistachio Commission.
Hanford, CA. 

cc: Pistachio Commodity File, B.A. Schneider, R.F., Crop Group File.

B.A. Schneider:(3/3/97):804V:CM#2:(703)305-5555:7509C

RDI: R. Loranger (8/20/96); E.Haeberer (8/14/96); R. Perfetti (2/13/97).

PART I - 	THIS LIST CONTAINS THE NINETEEN CROP GROUPS AND WHICH MEMBERS
OF THE CROP GROUP ARE MOST SIMILAR TO THEIR REPRESENTATIVE COMMODITIES

Crop Group 14:  Tree Nuts

Representative Commodities:  Almond and pecan

CROP GROUP COMMODITY		REPRESENTATIVE COMMODITY

     Almond					Almond

     Beech nut					Almond

     Brazil nut					Pecan

     Butternut					Pecan

   

      Cashew					Pecan

     Chestnut					Almond

     Chinquapin					Almond

     Filbert					Pecan

     Hickory nut				Pecan

     Macadamia nut				Pecan

     Pecan					Pecan

     Pistachio					Almond

     Walnut, black 				Pecan

     Walnut, English				Pecan

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