VALUE AND USE
SPECIES: Mahonia trifoliolata | Agarito 



WOOD PRODUCTS VALUE : 
NO-ENTRY


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Browse:  Agarito reportedly has no forage value for cattle, horses, or
domestic sheep, and has little value for domestic goats [29].  Less than
1 percent of the tender new sprouts were browsed by Spanish goats
following fire on the Edwards Plateau of Texas [49].  Agarito is browsed
by deer in some areas [35] but is generally considered an "undesirable
deer food" [5].  In some locations, twigs, bark, and leaves of
grape-hollies (Mahonia spp.) are eaten by the ringtail, and various
species of hares and rabbits [37].

Fruit:  Agarito berries are readily eaten by many species of small birds
[52] and mammals.


PALATABILITY : 
Leaves of agarito are spiny and unpalatable [29] and toughen with age
[53].  Mature leaves may remain palatable to some insects, such as
foraging ants, but often become too tough for the ants to cut [53].
Increasing toughness may deter large herbivores as well.

Berries are highly palatable to many species of small birds and mammals.


NUTRITIONAL VALUE : 
Nutrient value of agarito varies by plant part [30] and phenological
development.  The chemical composition of mature foliage has
been documented as follows [26]:
                        
                              percent 
protein  ether    crude   N-free   H20  ash  potash  lime  magnesia  phosphoric
         extract  fiber   extract                                    acid

10.32     2.38    30.59   46.61    6.13 2.97  0.91   0.88    0.24     0.34

Nutrient content by plant part and date is listed below [30]:

     plant part      date     water (%)   ash (%)    P (%)    protein (%)   

     shoots          3/27     69           4         0.27       16
     shoots          4/13     48           3         0.25       13
     shoots         10/25     71           4         0.27       16
     leaves+stems    3/28     71           4         0.29       15      


COVER VALUE : 
Agarito provides valuable cover for many wildlife species [43].  Clumps
or thickets serve as important hiding cover for white-tailed deer on the
rolling Texas plains [20].  Agarito forms good hiding, nesting, and
resting cover for a variety of small birds and mammals [35].  In parts
of Texas, wild turkeys occasionally nest beneath agarito [17].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Rehabilitation value of agarito is unknown.  However, plants can be
easily propagated from seed [24].  Seed can be planted in the fall, or
stratified and planted in the spring [43].  Agarito can also be
propagated by suckers, cuttings, and layering.  Properly treated
cuttings taken in early summer will usually root by fall [24].


OTHER USES AND VALUES : 
Roots of agarito contain berberine and other alkaloids and were
traditionally used to make preparations for treating toothaches and
stomach ailments [40,52].  However, these alkaloids are poisonous in
high concentrations [40].  Yellow dyes were made from the roots and wood
[52].

Fruit of agarito is edible [51] and can be used to make wine and jelly
[52].  However, Durand [24] cautions that when collecting the fruit of
Texas mahonias, "it is always a good precaution to poke around the bush
with a stick before threshing to make sure there are no rattlesnakes."
Seeds of agarito can be roasted and used as a coffee substitute [52].
Flowers provide nectar for honeybees, and consequently agarito is
considered to be a good honey plant [51,52].

The attractive leaves and flowers make agarito well-suited for use as an
ornamental [45].  It can be planted as a hedge or used singly [24,45].
When mixed with Amur privit, it forms an excellent and attractive
combination hedge [24].  The variety glauca has been cultivated in
England [1].  Agarito is relatively intolerant of cold temperatures and
in North America is not hardy north of zone 6 [46].


MANAGEMENT CONSIDERATIONS : 
Brushfield expansion:  During the past century, shrubs such as mesquite
(Prosopis spp.) and agarito have been increasing on Texas rangelands
[2,3,10,39].  An estimated 736,744 acres (1.82 million ha) of Texas
rangeland is now "infested" with agarito.  The situation is particularly
pronounced on the Edwards Plateau where agarito density can reach up to
121 plants per acre (300/ha) [19].  Possible causes of this shrub
expansion include fire suppression, overgrazing, and/or climatic change
[2,10].

Grazing:  In semiarid grasslands of Texas, heavy grazing apparently
favors the spread of redberry juniper (Juniperus pinchotii) which in
turn facilitates the establishment of agarito.  Frequency of agarito is
typically highest on grazed sites occupied by redberry juniper, as
illustrated below [39]:

            high plains                   rolling plains
   grazed sites    ungrazed sites       redberry      redberry
 present   absent  present absent       j. present    j. absent
                      (percent frequency)
      
    29       0       63      20               25         0  

Mechanical removal:  Ranchers commonly view agarito as a nuisance [24],
and numerous studies have focused on various means of mechanical removal
[19,22,23].  Soil penetration to a depth of 4 to 6 inches (10-15 cm) is
generally necessary to sever the taproot from the crown and to uproot
all lateral roots capable of resprouting.  Resprouting often occurs
where blade penetration is insufficient.  Small plants with shallow
roots are most readily killed by mechanical means [19].

On the Edwards Plateau of Texas, various types of mechanical grubbing
have produced erratic mortality [19].  Grubbing, using a modified blade
with fins on top, killed up to 93 percent of the plants where
pretreatment densities had ranged from 17 to 79 plants per acre
(42-195/ha).  Consequently, this method of control was judged both
effective and economical [19].  On rocky outcrops with shallow soil, the
blade was prevented from eliminating all of the lateral roots.  An
estimated 88 percent of agarito was killed on these sites.  Root plowing
is also effective, although often prohibitively expensive.
Posttreatment burning, when used in combination with mechanical removal,
can also aid in reducing agarito density [see Fire Management
Considerations].

Chemical control:  Agarito is resistant to many herbicides including
2,4,5-T and picloram [14,19,22].  Although canopies were reduced by 24
to 30 percent 13 months after large amounts of picloram were applied to
the soil, plants recovered within 24 months [33].  No plants were
actually killed by the herbicide.  Details on response to various rates
of herbicide application are available [14,29,22].

Damage/disease:  Agarito is susceptible to black stem rust [52].
However, roots contain large amounts of the alkaloid berberine, a
substance known to inhibit some root fungi.  Roots may, therefore, be
relatively resistant to a number of pathogens [24].

Biomass:  Models have been developed for predicting biomass estimates of
agarito.  Current growth is primarily leaves and includes little twig
elongation.  Studies indicate that new growth on young plants is greater
per unit volume than is growth on older plants [16].

Related categories for Species: Mahonia trifoliolata | Agarito