Effect of cutting frequency on yields and persistence of half-sib Lucerne families

Abstract

From the point of view of economy and profitability of crop production, it is desirable for lucerne fields to last a number of years. Frequent cutting (4-5 times a year) is the single most important factor contributing to reduced stand persistence in lucerne. The objective of this paper was to use progeny testing on 24 half-sib families obtained by open pollination in order to select those tolerant of frequent cutting during 2004-2006. Twenty four half-sib families differing in stand persistence were chosen from 17 source populations. The persistence was evaluated based on green forage and dry matter yields as well as the number of plants and shoots and coverage in the third year of plant life. The highest green forage yields in 2006. were produced by the half-sib family 176 04 (RCIM 60) with frequent cutting (77.4 t ha'1) and by 171 04 (Vertus) with less frequent cutting (84.4 t ha"1). The highest dry matteryields were recorded in 173 04 (NS Banat ZMS II) (18.04 t ha"1) in the frequent cutting system and by 171 04 (Vertus) (18.99 t ha"1) in the less frequent one. The largest numbers of plants per square meter were found in 144 04 (RQI 50) (108) and 173 04 (MS Banat ZMS II) (102) respectively, while the largest numbers of shoots per meter square were observed in 180 04 (Europe) (875) and 172 04 (Victoria) (960). At frequent cutting, the highest score for coverage was nine (given to 16 families) whereas at less frequent cutting, it was seven (given to six families). Based on the indicators of yield, plant and shoot numbers and ground coverage assessment, eight half-sib families were selected to be used as parents of synthetics with increased persistence under frequent cutting conditions.

U radu je analizirano potomstvo (progeni test) 24 polusrodne porodice u cilju odabiranja komponenata za sintetičku sortu veće perzistentnosti u uslovima učestalog košenja. Kao parametri perzistentnosti korišćeni su prinos zelene krme i suve materije tokom 2004-2006, kao i u trećoj godini života biljaka lucerke (2006) posebno. Broj biljaka i broj izdanaka po m2 su određene na kraju treće godine, a pokrovnost useva na početku četvrte go dine života. Na osnovu svih pokazatelja (prinosa zelene krme i suve materije broja biljaka i broja izdanaka i pokrovnosti površine usevom) u 2006. godini odabrano je osam polusrodnih porodica, koje će se koristiti za stvaranje sintetičke sorte veće trajnosti i u uslovima učestalog košenja.