Die evaluering van 'n aantal lusernkultivars t.o.v. hul droëmateriaalopbrengs en diereproduksiepotensiaal onderdroëlandtoestande in die Outeniqua-gebied van die Wes-Kaap

Abstract

The drymatter - and animal production of nine lucerne cultivars were evaluated under dryland conditions with SA Mutton Merino sheep at Outeniqua Experimental Farm (George). The nine lucerne cultivars that were chosen for this experiment, were already evaluated in cutting trials for their drymatter production. They consist of one winterdormant cultivar (Alfagraze), two semi-winterdormant cultivars (WL 320 and Meteor), five intermediate-winterdormant cultivars (SA Standard, Standard Tygerhoek, Aurora, Diamond and WL Southern Special) and one winteractive cultivar (Cuf 101). The mild climate of this area resulted mainly in a difference in drymatter production between the most winterdormant cultivar (Alfagraze) and winteractive cultivar (Cuf 101). The only difference in the rate of production of winterdormant types appear in winter and spring. The production rate of the winterdormant and semi-winterdormant cultivars was lower in the winter than that of the intermediate winterdormant (WL Southern Special) and the winteractive cultivar (Cuf 101). The drymatter production of the semi-winterdormant cultivar (WL 320) was higher than that of the winteractive cultivar (Cuf 101) in spring. There is a seasonal difference in the drymatter production of lucerne cultivars from the same winterdormancy class. Some of the more winterdormant cultivars also achieve a comparable and even higher dry matter production than that of the more winteractive cultivars. This tendancy is prominant between the semi-winterdormant cultivars (WL 320 and Meteor). WL 320 has a higher dry matter production than Meteor. It also has a higher or equal production rate, dependant on the seasons, than the winteractive cultivar (Cuf 101). A similar tendancy appears in the intermediatewinterdormant cultivar (WL Southern Special). The seasonal drymatter production and production rate of this cultivar are the same as that of Cuf 101. The appearance of annual grasses and weeds had a seasonal influence on the availability of dry matter and animal production. The grass production increases over the years resulting in up to 20% increase of the green matter during winter and spring. The grazing capacity of the winterdormant cultivar (Alfagraze) has increased during this seasonal grass production. The lucerne cultivar with the highest drymatter production rate and the highest seasonal dry matter production, also had the highest grazing capacity. The yearly and seasonal grazing capacity of WL 320, Aurora, WL Southern Special and Cuf 101 was generally higher than most of the other cultivars. This was also the most important reason for the high live mass increase with these cultivars.