VALUE AND USE
SPECIES: Halogeton glomeratus | Halogeton 



WOOD PRODUCTS VALUE : 
NO-ENTRY


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Halogeton is high in oxalates and is a serious health threat to grazing
animals, especially sheep [25,49,55,104,107].  A sheep will be killed by
12 to 18 ounces [0.3-0.5 kg] of halogeton [23].  Symptoms of halogeton
poisoning have been described [70,102].  There is no treatment once an
animal is poisoned [99].

The amount of soluble oxalates in halogeton varies by season, locality,
and part of plant eaten [55].  As a halophyte, halogeton makes excessive
amounts of oxalic acid in response to excessive uptake of sodium ions
[41].  While halogeton is growing, oxalates are highly concentrated; 17
to 30 percent of dry plant weight is soluble oxalates [25,55].  Sheep
can safely consume halogeton after the soluble oxalate concentrations
are reduced through leaf loss or leaching by rain or snow [23,55,109].
Additionally, calcium-fortified pellets have been recommended as
supplements to sheep feeding in halogeton range, to compensate for the
calcium precipitation from the blood by oxalates [23,25,103].  Van Dyne
[103] recommends against using halogeton as forage [103].  However,
other studies indicate that halogeton is useable when it is mixed in
small amounts with other forage [70,96].  Krueger and Sharp [57]
reported that sheep can adapt to halogeton if it is fed to them in
gradually increasing amounts.  Adapted sheep can detoxify 75 percent
more oxalate than nonadapted sheep [57].


PALATABILITY : 
Palatability is extremely low, and halogeton is seldom eaten by livestock
[24,99].  The palatability of halogeton is listed as poor for ungulates
in Montana, Utah, and Wyoming [28].  In Utah and Wyoming, halogeton
palatability is fair for small mammals, good for game and nongame birds,
and poor for waterfowl [28].


NUTRITIONAL VALUE : 
NO-ENTRY


COVER VALUE : 
Halogeton provides poor environmental protection for ungulates, game
birds, and waterfowl in Utah and Wyoming [28].  In these states, it provides
fair protection for small mammals and nongame birds [28].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Halogeton is a noxious weed that must be prevented from establishing on
denuded or disturbed soils in the semiarid shrublands of the western
United States.  Halogeton makes an area less favorable for revegetation
with other species; it is difficult to establish desirable plants where
halogeton occurs [59].  At mine reclamation sites, several studies have
measured changes in halogeton establishment or abundance over many years
[2,7,68,75].  One study examined leachate from three levels of halogeton
mulch.  They found significant soil alteration:  increases in pH,
exchangeable sodium, potassium, magnesium, electrical conductivity, and
decreases in water percolation [25,33].  High salts inhibit
micro-organisms aiding nitrification, which depresses plant growth [33].
Halogeton does not form mycorrhizae and does well in mine spoils with
diluted or eliminated vesicular-arbuscular mycorrhize [1,2,7].  Goodman
[42] added nitrogen to enhance native plant production, and halogeton
biomass doubled compared to unfertilized controls.


OTHER USES AND VALUES : 
NO-ENTRY


MANAGEMENT CONSIDERATIONS : 
Halogeton readily invades and dominates rangeland depleted by persistent
and continuous overgrazing [25,53,54,57,93].  Heavy sheep losses from
halogeton poisoning have occurred since 1940 on ranges in Idaho, Nevada,
and Utah [4,15,66,89,91,95].  The rapid spread of halogeton from 1935
through the 1940s, coupled with extensive livestock poisonings, resulted
in the Federal Halogeton Control Act [63].

The best defense against halogeton is a vigorous stand of perennial
range plants and variations in grazing patterns [4,15,47,77,101].
Moderate range use only after the growing season is the wisest halogeton
strategy [54,105].  Efforts must be taken to prevent vegetation
destruction by rodents and rabbits, road construction, surface mining,
or the use of off-road vehicles [15].

Three methods are used to control halogeton [24].

(1) Cultural control:  Introduced perennials, such as immigrant kochia
(Kochia prostrata), were planted with successful decrease in halogeton
cover [67,94].  Crested wheatgrass (Agropyron cristatum and A.
desertorum) was seeded extensively in depleted winter rangeland to slow
halogeton growth [65,111,113 but see 64,76].  Crested wheatgrass does
not suffer from halogeton competition, but from the saline-alkaline site
conditions where it occurs [20].  Some hybrids (for example, A.
desertorum cv.  Hycrest) can tolerate saline conditions.  Asay and
Johnson [3] found that a heavy halogeton infestation was essentially
elimated by year 2 after seeding with Hycrest.

(2) Biological control:  A stem-boring moth (Coleophora porthenica) from
Pakistan was released for halogeton control [77].  However, it failed to
establish.  The search for a biological control agent continues in
Soviet central Asia [77].  A case-bearing moth (Coleophora
atriplecivora) has been found on halogeton [69].  It is not currently
known what effect it has on halogeton; however, Moore and Stevens [69]
found that the case-bearing moth reduced seed production and foliage in
fourwing saltbush (Atriplex canescens).

Altered grazing practices can slow halogeton spread.  Studies showed
that high intensity grazing in early spring (March and April) increased
halogeton cover significantly in Utah [106].  Heavy spring grazing
causes rapid rangeland deterioration [60].  Halogeton was reported to
decrease in Nevada under early (mid-April to mid-June) grazing at
moderate intensity [85].

(3) Chemical control:  Halogeton is susceptible in the preflowering
stage to 2,4-D at 2 pounds active ingredients per acre (2.2 kg ai/ha)
[25,37,80].  Approximately 17 percent of the plants survive this rate
[101].  Higher 2,4-D rates of six pounds active ingredient per acre (6.7
kg ai/ha) are recommended to kill all halogeton; however, native plants
are severely impacted [23].  The application of 2,4-D must be repeated
annually for 6 to 10 years after the final halogeton seed crop [99].

Herbicide control is too expensive to be used on low-production ranges
on which halogeton occurs [77,78].  Widespread herbicide control of
halogeton was stopped because land managers did not have desirable
forage to replace halogeton, especially on saline-alkaline soils
[21,66,101].

Related categories for Species: Halogeton glomeratus | Halogeton