VALUE AND USE
SPECIES: Toxicodendron radicans | Poison-Ivy 



WOOD PRODUCTS VALUE : 
NO-ENTRY


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Animals generally are not susceptible to poison-ivy-induced dermatitis
[60,109].

In southern Indiana, poison-ivy was one of the seven most important taxa
consumed in winter by white-tailed deer [106].  Two studies showed that
white-tailed deer preferred to eat poison-ivy over other available
browse [55,85].  Poison-ivy leaves were eaten by white-tailed deer with
greater frequency in summer (81 percent) than in spring (67 percent)
[85,106].  Nixon and others [90] reported that white-tailed deer ate
poison-ivy fruits as a principal food item; fruits were consumed fall
through spring.

Poison-ivy produces soft mast [88].  A wide variety of migrant and
resident nongame and upland game birds consume the fruits; it is
considered a preferred species [11,45,56,64,77].  Ripe fruits become
conspicuous and are usually one of the most abundant foods available for
birds in fall and winter [45,61,77,79,126].


PALATABILITY : 



NUTRITIONAL VALUE : 
NO-ENTRY


COVER VALUE : 
NO-ENTRY


VALUE FOR REHABILITATION OF DISTURBED SITES : 
For 50 years, poison-ivy has been planted to prevent dike erosion in the
Netherlands [39].

To restore Louisiana bottomland that had been cleared for farming, oaks
(Quercus spp.) were planted.  Other species, including poison-ivy, were
allowed to move in naturally.  Within several years, poison-ivy occurred
in all land sites in varying densities [5].


OTHER USES AND VALUES : 
Poison-ivy sap has been used to make indelible ink [120].

Despite its dermatitis-causing properties, poison-ivy is cultivated in
gardens [39].  It is used for horticultural displays where it is valued
for its red autumn foliage [39].


MANAGEMENT CONSIDERATIONS : 
Poison-ivy sap causes allergic contact dermatitis in humans [72].  The
active agent is urushiol, which exudes from broken resin ducts in most
plant parts [84].  Plants are variously poisonous depending on time of
year and plant maturity, and people vary in susceptibility [79,109].
Symptoms and treatment are detailed [27,71,72,79].  Ingested leaves do
not confer immunity and can cause humans serious gastric disturbance
[60,109].

Poison-ivy is an important component in wetlands used for sewage
management.  Secondarily treated waste water or waste water from a
septic tank has been dumped into pond cypress (Taxodium distichum var.
nutans) stands for over 45 years; numbers of poison-ivy plants did not
decline [87].  Ewel [29] compared vegetation occurring on cypress domes
after various treatments with waste water; poison-ivy persisted despite
the treatments.  Nutrient changes did not exclude poison-ivy in New
Jersey wetlands; poison-ivy occurred with high cover in control and
developed sites near unpaved roads, septic systems along wetland edges,
and direct stormwater sewer outfall [26].

In eastern cottonwood (Populus deltoides) stands thoughout the
Mississippi Valley, poison-ivy vines of 4 to 5 inches (10.2-12.7 cm) in
diameter grow up tree boles.  There is conflicting literature stating
that poison-ivy does and does not inhibit eastern cottonwood diameter
growth [58].

Presence or absence of canopy cover does not influence poison-ivy
growth.  There was no significant (p>0.05) difference in poison-ivy
productivity, measured as leaf area and biomass, after canopy removal in
mixed hardwood stands in southern Michigan [78].  With a gradual
increase in canopy closure (from 9 to 40 percent tree cover) and a
cessation of grazing, poison-ivy cover only marginally increased [32].

Poison-ivy sometimes is an invading species.  Although no attempts were
made to control it, poison-ivy was a competing understory vegetation
with oak seedlings in Pennsylvania and Maryland [50].  Hardin [44]
evaluated an Ohio mixed oak-prairie tension zone that was not actively
managed for 22 years.  Poison-ivy was not present originally; however,
after 22 years, it had an 8 percent cover in the transition zone.
Poison-ivy was a principal invader of this grassland, with greatest
abundance under overhanging tree limbs [44].

Biological Control:  Grazing can control poison-ivy under specific
conditions; very heavy grazing inhibits fruit production [28].  However,
this is considered a stop-gap measure because release from grazing
results in heavy poison-ivy infestations [28].

In the southeastern United States, larvae of poison-ivy sawfly have been
studied as possible control agents for poison-ivy [28].  Poison-ivy is
parasitized by a rust (Pileolaria shiraiana) which may offer future
biological control [39].

Chemical Control:  Poison-ivy should be treated with herbicide before
flowering [28].  However, Kunzmann and Bennett [68] suggest that
herbicide application should be at the height of the growing season,
which is after flowering.  Evans [28] recommends using glyphosate at 1
to 4 pounds active ingredient per acre (1.1-4.5 kg ai/ha) in the spring
(May) or fall (September to November).  Poison-ivy foliage has been
wiped with a 2 percent solution of glyphosate for successful control
[86].  Poison-ivy has been controlled with 3 to 4 pints active
ingredient per acre (3.5-4.7 L ai/ha) of imidazolinone [68].

Related categories for Species: Toxicodendron radicans | Poison-Ivy