Recovery and Viability of Macartney Rose Seeds Fed to Cattle

Abstract

T HE INVASION and spread of noxious woody plants over the 93.5 million acres of range lands in Texas have resulted in lowered grazing capacity, increased livestock handling costs and lowered returns to the operator. This infestation includes an estimated 40,000 acres (Allred, 1948) of Macartney rose, Rosa bracteata Wendl. in the upper coastal region. This species also is known locally as Chickasaw rose, hedge rose, and wild rose. The noxious character of the Macartney rose in grazing land was recognized by Hume (1943) and again by Taylor (1949). Both attributed the increase and spread of Macartney rose on range lands to seed disseminated by livestock and by birds. This rose species also reproduces vegetatively, sprouting profusely from the base of the main stem and from shallow lateral roots if the top is killed or removed. Taylor believes that birds are the most important agents of seed dispersal. A native of China, the Macartney rose was introduced into England prior to 1800 by a diplomatic mission headed by Lord Macartney (Keays, 1942: Hume, 1943). It was subsequently introduced into the United States, and is believed to have spread westward into Texas from the port city of New Orleans (letter from S. W. Geiser, Oct. 12, 1948). At one time it was recommended as a hedge plant because of the high cost of initial fencing (Webb, 1931). Relics of many of these old hedges may still be seen in south Texas, many apparently furnishing the nucleus for local infestation. Individual plants of Macartney rose form dense clumps ten or more feet in height and several yards wide (Fig. lA). These clumps may coalesce to form dense impenetrable thickets along fence lines and drainage ditches and in river bottoms. Loudon (1880) states that the plant grows best on loam soil in England, but it is often found in Texas on clay or sandy soils. A study has been made by the Department of Range and Forestry of the Texas Agricultural Experiment Station to determine some of the factors relating to the spread and establishment of Macartney rose on land used for grazing. This study consisted of four phases: (1) to determine the proportion of recovered seeds of the Macartney rose which is physically damaged in the bovine digestive tract; (2) to determine the viability of apparently sound seeds after passage through the digestive tract of cattle; (3) to determine the influence of retention within the fecal material on the viability of the seeds; and (4) to determine the necessity for cold stratification, a standard nursery practice with ornamental roses, in germinating seeds of the Macartney rose. Rose seeds are known to pass through certain mammals and birds unharmed. Harmon and Keim (1934) recovered 13.3 percent of Rosa arkansana seeds fed to yearling calves during the four days following ingestion. No germination was obtained by these authors, possibly because the seeds were not subjected to cold stratification for after-ripening. Seeds of a rose species in Minnesota passed through