A series of trials to increase understanding of the summer dormancy trait inPhalaris aquatica was conducted. Autumn-sown and younger, spring-sownplants of two cultivars (cvv), known to contrast in expression of summer dormancy,were established and then tested over the following summer underthree moisture regimes: long drought; drought + mid-summer storm; or fullirrigation. The autumn-sown plants of cv. Atlas PG expressed substantial butincomplete summer dormancy under all moisture regimes and exhibited thecharacteristic responses including significant growth reduction and herbagesenescence. The summer-dormant cv. Atlas PG used 31 mm less soil water overthe summer and also began to rehydrate its leaf bases from conserved soilwater before the drought broke. The non-dormant cv. Australian grew whenevermoisture was applied and also responded to the mid-summer storm witha decline in dehydrin expression in leaf bases, whereas no decline occurred inAtlas PG, presumably because it remained dormant. The irrigated, younger,spring-sown swards of cv. Atlas PG had restrained growth and produced onlyabout 37 % of the herbage of cv. Australian. Drought reduced activity andgrowth of young plants of both cultivars but while Australian regrew inresponse to the storm, cv. Atlas PG, grew much less (59 % of Australian) indicatingthat dormancy, although only partially expressed after spring sowing,was reinforced by summer drought. Australian used more soil water over summerthan Atlas PG, and it is suggested that this is why cv Australian is limitedto the higher rainfall zones of south-eastern Australia, particularly where soilwater holding capacity is limited
|Number of pages||13|
|Journal||Journal of Agronomy and Crop Science|
|Publication status||Published - 2012|
Norton, M., Lelievre, F., & Volaire, F. (2012). Summer dormancy in Phalaris aquatica L., the influence of season of sowing and summer moisture regime on two contrasting cultivars. Journal of Agronomy and Crop Science, 198(1), 1-13.