Tillering in native and introduced, warm-season perennial grasses in southwestern Buenos Aires

TORRES, Y.A., C.A. BUSSO, O.A. MONTENEGRO, H.D. GIORGETTI, G.D. RODRÍGUEZ, T. MONTANI Y A. MAIDANA

Tafí del Valle, Tucumán

Jornada; XXIV Jornadas Científicas de la Asociación de Biología de Tucumán; 2007

Asociación de Biología de Tucumán

This research evaluated tiller production in the native, warm-season, perennial grass Pappophorum subbulbosum and in 2 cultivars of warm-season perennial grasses introduced from the U.S.A.: Leymus cinereus cv. ‘Magnar’ and ‘Trailhead’. Studies were conducted at the field in the Chacra Experimental de Patagones. A defoliation treatment at 5 cm stubble height was applied to half of the plants, without removing the apical meristems. The other half remained undefoliated (control). Every 21 days, numbers of daugther tillers/parent tiller and basal area were determined.  Greater values of daughter tiller production/cm2, with the subsequent basal area expansion in P. subbulbosum, suggest a greater defoliation tolerance in the native than in the introduced cultivars. Height and tiller production reductions in the introduced genotypes could eventually compromise their persistence in the community. This is because vegetative reproduction (tillering) is the predominant way of reproduction in semiarid grasslands.