Winterhardiness and Agronomic Performance of Wildryes (Elymus species) Compared With Other Grasses in Alaska, and Responses of Siberian Wildrye to Management Practices

Leslie J. Klebesadel, Emeritus Professor of Agronomy

Agricultural and Forestry Experiment Station; Palmer, Alaska

Bulletin 97; December 1993 (19 pages)

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SUMMARY

This report summarizes eight field experiments involving both native and introduced wildrye grasses (Elymus species) conducted over a span of several years at the University of Alaska's Matanuska Research Farm (61.6oN) near Palmer in southcentral Alaska. Objectives were to (a) evaluate winterhardiness, persistence, forage yield, and other aspects of agronomic performance of numerous strains within several species of wildrye, (b) assess their potential for forage use or conservation plantings in Alaska, and (c) determine the effects on Siberian wildrye (E. sibiricus) of seeding-year management options (time of planting and time of harvest) on seeding-year forage production, subsequent winter survival, and on second-year forage production.

Experiment I

(Individual plants in rows)

· All 9 strains of Siberian wildrye evaluated (7 from the U.S.S.R., 1 from Mongolia, 1 from Alaska) showed excellent winter survival, most at 100%, none less than 94%.

· Percent winter survival was excellent also in Alaska collections of beach wildrye (95%) and downy wildrye (96%).

· Three strains of Russian wildrye (Mayak, Sawki, P-9012) were near-similar in winter survival, averaging 87%.

· Altai wildrye and the Volga cultivar of mammoth wildrye were intermediate in winter survival; Altai survival was 72% and Volga 37%.

· One strain each of Canada wildrye (P-3355), basin wildrye (P-5797), and antarctic wildrye were nonhardy; winter survival of all three was 0%.

· Other grasses that winterkilled totally were Hattfjelldal and Va-BL-67 orchardgrass, and Vagones and Loken meadow fescue, all from Norway.

· Non-Elymus grasses that survived the winter at 100% were Polar and pumpelly bromegrass, Garrison creeping foxtail, and native Alaskan arctic wheatgrass.

Experiment II

(Broadcast-seeded plots for forage)

· Seeding-year forage yields of all nine strains of wildrye within seven species and pumpelly bromegrass were low, compared with yields of timothy, meadow fescue, orchardgrass, creeping foxtail, and smooth bromegrass.

· Numbered strains of Canada wildrye (P-3355) and basin wildrye (P-5797) were the least winterhardy of the 20 grass strains compared; both winterkilled completely the first winter. Other relatively nonhardy grasses that sustained over 90% winterkill during the first winter were mammoth wildrye (cultivar Volga), Altai wildrye, Loken and Vagones meadow fescue from Norway, and Hattfjelldal and Va-BL-67 orchardgrass from Norway.

· Intermediate in winterhardiness during the first winter (all rated at 60% winterkilled) were Russian wildrye cultivars Sawki and Mayak from Saskatchewan and strain P-9012 from Washington state.

· Grasses with no apparent winter injury during the first winter were native Alaskan beach and Siberian wildryes, Polar and native pumpelly bromegrass, native arctic wheatgrass, Garrison creeping foxtail, and Engmo and Bodin timothy cultivars from Norway; stands of Va-BL-60 timothy from Norway were rated 10% winterkilled.

· Grasses that were severely injured during the first winter, produced little or no harvestable forage during the second year, and winterkilled totally during the second winter were Altai wildrye, Loken and Vagones meadow fescue, and Hattfjelldal and Va-BL-67 orchardgrass.

· The only wildryes from sources outside of Alaska that persisted and produced a forage yield for the full 4-year term of the experiment were Sawki and Mayak Russian wildrye; however, those yields were less than one-third of the highest yielding grasses in other species.

· Native Alaskan Siberian and beach wildryes were more winterhardy, and Siberian wildrye produced more forage than all wildryes from elsewhere. The very open character of the beach wildrye stands, however, permitted weed ingress into those plots to the extent that no forage yields were obtained from that grass in the fourth year.

ii

· Seven non-Elymus grass strains surpassed all wildryes derived from sources outside Alaska in winterhardiness, persistence, and forage yields, averaging over 3 tons of dry matter per acre; those were three strains of timothy from Norway, Garrison creeping foxtail, Polar bromegrass, and native Alaskan pumpelly bromegrass and arctic wheatgrass.

Experiments IIIa, IIIb, IIIc, IIId

(Siberian wildrye compared with other

grasses in broadcast-seeded plots for forage)

· In four similar experiments, each six years in duration, total yield of native Alaskan Siberian wildrye was about three-quarters that of Polar bromegrass, but more than twice as much as Sawki Russian wildrye. Total yield of Sawki was similar to that of Engmo timothy.

· Stands of Siberian wildrye showed evidence of senescence in the fifth and sixth years of the experiments, becoming less productive then than stands of the longer-lived Polar bromegrass; Polar stands were fully productive for the full 6-year term of all four experiments.

· Stands of Sawki winterkilled totally before completion of three of the four experiments; Engmo timothy stands winterkilled about midway through two of the experiments, but persisted for the full term of the other two tests.

Experiment IV

(Broadcast-seeded plots for forage)

· Grasses in this experiment were favored by above-average precipitation during the seeding year, but were under considerable moisture-deficit stress during the following two years when two harvests were taken each year.

· Highest seeding-year yields were produced by two Siberian wildryes from Asia, Signal smooth bromegrass, seven timothy cultivars, and Frontier reed canarygrass; these averaged 2.46 tons oven-dry forage per acre.

· Relatively mild winters permitted some typically nonhardy grass strains to survive (e.g., Climax timothy) for the full term of the experiment; Frontier reed canarygrass, the only grass that did not persist for the full term, sustained severe injury during the first winter and winterkilled totally during the second.

· Of the 29 grass strains harvested over a 3-year period, the two strains of Siberian wildrye from Asian sources ranked first and second; the third strain of Siberian wildrye, from Alaska, ranked 20th.

· As a group, four cultivars of smooth bromegrass generally ranked second in yields to the Asia-origin Siberian wildryes, and seven timothy cultivars ranked generally below those bromegrasses.

· Arctared red fescue, quackgrass, and Nugget Kentucky bluegrass were intermediate in total yield.

· Under the drought-stress conditions of the last two years of this experiment, all native Alaskan grasses were generally low yielding; these included pumpelly bromegrass, Norcoast hairgrass, six strains within four species of wheatgrasses, and American sloughgrass.

Experiment V

(Seeding-year management effects

on Siberian wildrye)

· Seeding-year forage yields from plantings on 19 May and 6 June averaged 2.81 and 2.49 T/A, respectively, and were little influenced by six different harvest dates from 20 August to 6 October.

· Seeding-year forage yields from grass planted 24 June were much reduced from those of the earlier two planting dates, and generally increased with successively later harvest dates from 20 August (0.46 T/A) to 6 October (1.43 T/A).

· Second-year first-cut forage yields from Siberian wildrye that had been planted 19 May or 6 June were uniformly high, averaging 2.58 and 2.57 T/A, respectively, and showed no harmful effects from any of the seeding-year harvests.

· With grass planted later (on 24 June), however, seeding-year harvest near mid-September predisposed the grass to severe winter injury; the thinned and weakened stands produced very low forage yields in the first cutting of the second year. Seeding-year harvests were less injurious to the grass as they were taken increasingly earlier or later than mid-September.

· These results indicate that the youngest (latest-planted) seedlings were more susceptible to inappropriate seeding-year harvest dates than older, earlier planted seedlings that had a longer growth period for development and physiological preparation for winter.

General

· To derive full benefit in Alaska from broad-based, unselected genetic reservoirs, plant introductions (such as wildryes) from Eurasia should be drawn not only from the northernmost areas of their natural ranges on that continent, but also should be brought directly to Alaska for evaluation and selection.

· Bringing to Alaska plant strains that have originated in northern areas but were introduced into North America at lower latitudes for evaluation and selection (thereby selecting within and narrowing their gene base for ideal performance under environmental conditions at those lower latitudes) discards valuable genetic elements that confer optimal physiologic harmony with far-northern climatic peculiarities common to both Alaska and the origin of the plants.