Influence of Temperatures, Water Stress, and Nitrogen Treatments on Chlorophyll and Dry Matter of Western Wheatgrass

Abstract

Western wheatgrass (Agropyron smithii Rydb.) raised from seeds was given four treatments under three temperature regimes in environment controlled growth chambers. Dry matter and chlorophyll (a + b) were determined in the shoots of these plants at 20-day intervals for 100 days. Dry matter and chlorophyll production was greater from irrigated and irrigated-plus-fertilized plants under each temperature regime than it was from control or fertilized plants. This response was more pronounced at the intermediate temperature regime (24/13 degrees C) than that at the lower (13/7 degrees C) or the higher temperature regimes (30/18 degrees C). The maximum chlorophyll increase of irrigated and irrigated-plus-fertilized plants was 350% and 395% at 24/13 degrees C while in the control and fertilized plants the increase was 251% and 176%, respectively. A positive linear relationship was found between dry matter and chlorophyll of all the plants under the three temperature regimes.