Influence of Simazine on Yield and Quality Components of Reed Canarygrass1

Abstract

AbstractThe use of the chloro‐substituted triazines as a tool for modifying plant growth has received increasing attention. The study reported herein evaluated the influence of 2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine (simazine) as a growth regulator. In 1969 simazine was applied at rates of 0, 0.28, 0.56, and 1.12 kg/ha in both split and single applications to reed canarygrass (Phalaris arundinacea L.) supplied with either 224 or 448 kg N/ha. Three harvests were taken. Single applications of simazine at rates of 0.56 and 1.12 kg/ha significantly (P < 0.05) depressed dry matter yields; when applied in split applications, 0.56 kg/ha did not depress yields. Yields of crude protein were depressed by single applications of 1.12 kg/ha of simazine, while single applications of both 0.56 and 1.12 kg/ha of simazine depressed yields of in vitro digestible dry matter (IVDDM). However, split applications of simazine at 1.12 kg/ha did not significantly affect yields of crude protein or IVDDM. Percent crude protein, alcohol‐insoluble N, NO3‐N, and in vitro dry matter digestibility (IVDMD) were increased, while cell wall components were decreased by simazine application. The extent of these changes in composition varied with rate and method of simazine application. In 1970, simazine treatments of 0, 0.28 kg/ha applied as a single application, and 0.56 kg/ha applied ia split applications were made to reed canarygrass. Responses to simazine applications at these levels in 1970 were similar to those observed in 1969. The observed changes in composition suggest that the nutritive value of reed canarygrass was improved.