Syrian mesquite (Prosopis farcta)

Weed

Prosopis farcta is among the most prevalent weeds in sesame fields in Turkey and in range land in the USA. It affects a large area in the Jordan Valley. An additional probem is that Prosopis farcta is the primary host of different plant parasites (dodder) and insect parasites (for example the white fly Bemisia tabaci, vector of the tomato yellow leaf curl virus). A drought-resistant species, Prosopis farcta regenerates from seeds and basal buds on the rhizomes located at or just below the soil surface. It resumes growth after a very short dormancy period in the winter and spring, and re-vegetates during the summer through the autumn (Qasem, 2007).

It is generally difficult to eradicate. Weeds can penetrate plastic covers. Rhizomes and seeds are unaffected by soil solarization treatments. Burning and hoeing are ineffective as these methods leave the parts below ground, and hoeing may break the rhizomes into viable fragments, thus further increasing encroachment. Attempts to remove the weed from cultivated land are usually unsuccessful because the weed soon resumes vegetative growth and then spread rapidly. Grazing may be partially effective in reducing its vegetative mass but only at early growth stages when the thorns and branches are still soft, because after that the weed may only be grazed by camels. Control from grazing pressure alone may at best decrease the rate of invasion and will not entirely prevent weed invasion (Qasem, 2007).

Potential benefits

In Iraq, profitable barley cultivation was found to depend on the existence of Prosopis farcta in the fields. This species counteracts salinity and maintains porosity of the soil by deep rooting. Tolerance to drought and salinity is advantageous for soil improvement and to control erosion. It is also liked by bees, and is a useful fodder for cattle and sheep in desert areas (Hanelt et al., 2001).