TheImprovement ofTropical and Subtropical Rangelands

17( IMPROVEMENT 0' mOPIGAL AND SUBTROPIGAL RANGELANDS
FIGURE 7-11 TIlbepak colltaiDer for Ill.. propaptioll of pluta for hall__
plalltiDe ill harsh .it.. Ribbed walk of colltaiDer direct the powth of roota
downward ud produce a root plq 0.2 III loq (McKell, 1986).
Growth Container and Potting Media
Barker and McKell (1979) grew fourwing saltbush and ~
wood (Sarco6catu vermictllatu) in four sis. and typ. of containers
ranging from 98 to 1,147 ems and found that shoot length, shoot
bioDUUl8, and root biomaa all increued with trise of container. A
large variety of containers is available ranging from anall units in
plastic or styrofoam trays to nUl'llery pots: an ideal container is
Tubepak (figure 7-U).
The b.t container trise for good field performance is not neeeaarily
the beet container for eeedHng growth in the greenhouse.
Planta grown in large containers generally perform beet in the field
but require too much greenhouse space and are co8tly to handle and
ship. The best container also vari. with plant speci. and environmental
and soil conditions on the outplanting site.
The potting mix should be near pH 5.5 and have an electrical
conductivity reading of lea than 2.0 miJ)jmboe. Although there is
much variation in potting mixes, mixtures of plain sand with sieved
cow manure at a ratio of 1:1 are generally lI&tisfactory (Weber, 1986).
However, in some instances, special mix. may be desirable. For
example, Ferguson and MODSen (1974) found that mixes containing
peat m08l'J and vermiculite produced better mountain-mahogany
(Cercocar,u letliloti..) seedlings than did thOle containing sand.
Ferguson (1980) studied 39 different potting media and found that
no one mix was consistently superior. He did report that a potting
mix of 50 percent peat moa, 30 percent arcillite aggregate, and 20
percent vermiculite is recommended for Bonneville saltbush (Atri,lez
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