Delayed Germination of Cheatgrass Seed

Abstract

Highlight: Cheatgrass seeds germinate readily and usually near 100% shortly after collection. Generally, practically all seeds that fall to the ground germinate and plants emerge with favorable conditions in the fall, during the winter, or in early spring. In this study, an average of 692 cheatgrass plantsIft emerged the first year. In the same soil samples, 273 seedsIft did not germinate but produced plants when these seeds were brought into favorable conditions in the greenhouse. When these ungerminated seeds remain in the soil-litter mass in the field, they germinate and emerge more slowly than seeds brought into the greenhouse. Seeds that remain in seedheads over winter germinate slowly but with a high percent when placed in a germinator. Nitrogen at 80, 160, 320, and 640 lb/acre caused the number of plants that emerged in the field to decrease slightly as the rate of fertilizer increased. Cheatgrass (Bromus tectorum L.), an aggressive introduced winter annual, is well adapted to large areas of rangeland, especially in the western Authors are range scientist and range technician,

Impact of the pathogen Pyrenophora semeniperda on Bromus tectorum seedbank dynamics in North American cold deserts

“…These values are similar to those reported by other workers (Young et al. , 1969; Hull & Hansen, 1974; Humphries & Schupp, 2001). Late spring seedbank densities and first‐year seedbank carry‐over percentages in our study also fell within the range of previously reported values (Chepil, 1946; Hulbert, 1955; Young et al.…”

“…(1969) reported that density of carry‐over seeds in the seedbank in May on sagebrush sites in Nevada in an average year was as high as 5000 seeds per m 2 , while in a year with a long, wet spring there was very little seed carry‐over. Hull and Hansen (1974) measured first‐year in situ seedbank carry‐over of 1.7–17% at sagebrush sites in northern Utah and southern Idaho, while Wicks (1997) measured carry‐over as high as 30% in Nebraska. These studies indicate that B. tectorum populations frequently carry seeds over to the second year following production, but there is little evidence for seedbank persistence beyond 3 years.…”

Seed Bank Depletion: The Key to Long-Term Downy Brome ( Bromus tectorum L.) Management

“…Additionally, downy brome seed mass can provide the necessary litter to support successful germination and establishment . Downy brome germination is high (95% or more) and quite rapid when soil moisture and temperature are favorable (Hull and Hansen 1974). Downy brome seeds also are relatively insensitive to moisture and temperature stress (Goodwin et al 1996).…”

Postfire Downy Brome (Bromus tectorum) Invasion at High Elevations in Wyoming

“…Downy brome seeds readily germinate during low temperatures of fall, winter, or early spring (, 5 C [41 F]) resulting in seedling emergence in large numbers ranging from 1,960 to over 14,000 seedlings/m 2 (Buman and Abernethy 1988;Hull and Hansen 1974;Martens et al 1994;Wilson et al 1974). Once germinated, downy brome seedlings develop quickly at cool temperatures relative to other grass species (Aguirre and Johnson 1991).…”