Seed yield of three Bromus species native to western Canada

Abstract

There is an increasing demand to use native grass species for revegetating disturbed sites such as logged clearcuts. The value of such species is closely linked with their ability to produce seed. We compared seed yield of three native Bromus species (Bromus carinatus Hook. & Arn., B. ciliatus L., and B. anomalus Rupr. Ex Fourn.) and three domestic forage species (B. riparius Rehm., B. inermis Leyss., and Dactylis glomerata L.) and tested the hypothesis that native species divert fewer resources to reproductive growth than do domestic grasses. Six experiments were conducted at five locations in western Canada to evaluate the potential for seed yield from native brome. Bromus carinatus seeds ripened, on average, the first week of August, similar to B. riparius and D. glomerata, while seed of B. anomalus and B. ciliatus ripened about the third week of August, similar to B. inermis. Seed yields were highly variable among sites and between years. Over all sites, yields among species were not significantly different (P = 0.05). Mean second-year yield was less than half of that of the first harvest year. Yields of 2–3 t ha−1 were found for B. anomalus, B. ciliatus and B. inermis at certain sites. Seed yields were positively correlated to inflorescence number m−2 in both harvest years and to harvest index in the first harvest year. Based on seed yields that were similar to B. inermis in this study, it should be possible to produce sufficient quantities of reasonably priced seed of native Bromus species for the revegetation industry. Key words: Smooth bromegrass, meadow bromegrass, orchard grass, Bromus sp., Dactylis glomerata