A Superior Accession of Western Honey Mesquite (Prosopis glandulosa var. torreyana) for Riparian Restoration Projects

Abstract

An accession of western honey mesquite (Prosopis glandulosa var. torreyana) was identified at a riparian restoration project on the Gila River near Tacna in southwestern Arizona which grew faster than other honey mesquites at the same site. This "Tacna" accession appeared to be resistant to or grew despite infestations of psyllids (aphid-like insects) which damaged or killed other honey mesquite planted at this and other restoration sites. Seedlings of the Tacna accession, lower Colorado River P glandulosa var. torreyana from near Blythe, California, and P. alba, a hardy South American species popular as an ornamental in the Southwest, were planted at Fortuna Pond on the Gila River near Yuma, Arizona to compare survival, growth, and the effects of psyllids among mesquite types. Two years after planting, survival was similarly high (92 %) for all types, but growth indices (maximum height + maximum width) of the Tacna accession andR alba were significantly greater than the lower Colorado River accession (p <.001). Median growth index of the Tacna mesquite was 146% of the lower Colorado River mesquite growth index two years after planting. Infestations of psyllids occurred on all three mesquite types, but despite their association with severe damage and mortality in previous restoration efforts, relatively few seedlings were damaged. Psyllid presence and damage were not negatively correlated with growth indices (p >.05). The success of riparian restoration projects could be enhanced by planting Tacna mesquites. This accession could be used for fuelwood, ornamental plantings, and other purposes, as well.