From the current issue:
The fight against Poa annua (annual bluegrass) contamination is a continuous battle that incldues a combination of cultural and chemical practices, but does cultivar selection have an effect? Researches in Italy say it may. A study specifically looked at two types of spreading Lolium perenne (perennial ryegrass) versus two traditional varieties. The researchers wondered if creeping type perennial ryegrasses would be more competitive against Poa annua. they chose Jacklin's CSI spreading ryegreass to help answer that question.
The researchers planted plots of perennial ryegrass in October 2012, and once the plots were completely established, sowed annual bluegrass seed into a marked area in the middle of each plot.They also sowed annual bluegrass into bare ground as a control. Beginning in February 2013, annual bluegrass seedlings were pulled from each plot and counted weekly. The study was repeated in 2013-2014, and the results over 2 years confirmed that CSI and the other creeping ryegrass were more competitive against Poa annua than the traditional varieties. The study concluded that the creeping types of perennial ryegrass may reduce annual bluegrass infestation (Masin, Macolino 2016). the full study, "Seedling Emergence and Establishment of Annual Bluegrass (Poa annua) in Turfgrasses of Traditiona and Creeping Perennial Ryegrass," can be found in the January-March 2016 issue of Weed Technology (2016 30:238-245).