Timothy in Alaska: Characteristics, History, Adaptation, and Management

Leslie J. Klebesadel, Emeritus Professor of Agronomy

Agricultural and Forestry Experiment Station; Palmer, Alaska

Bulletin 105; October 1997 (44 pages)

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SUMMARY

This report (a) summarizes the characteristics of timothy (Phleum pratense L.) as a forage species, (b) reviews briefly the history of its use in the U.S., and the history of timothy evaluations and culture in Alaska, (c) compares winterhardiness of alpine timothy (P. alpinum L.) with common timothy, (d) compares physiological and morphological characteristics of timothy cultivars from widely divergent latitudinal origins and relates those characteristics to winter survival, (e) compares planting dates and different seeding­year harvest dates for seeding­year forage production and effects on subsequent winter survival and productivity, and (f) evaluates forage production of established timothy under a broad array of harvest schedules and frequencies, and compares the effects of those harvest treatments on subsequent winter survival and first­cut forage yield the following year.

All experiments were conducted at the University of Alaska Agricultural and Forestry Experiment Station's Matanuska Research Farm (61.6oN) near Palmer in southcentral Alaska.

·Alpine timothy collections (3 from Alaska, 1 from Iceland) winterkilled 100% during the first winter; in the same test, 22 cultivars of common timothy from northern Europe ranged from 71% to 100% winter survival (Exp. I).

·In addition to inferior winter survival, the comparatively meager production of stems and foliage of alpine timothy, despite adequate added fertilizer nutrients, eliminated that species from consideration as a worthwhile, productive cropland forage grass (Exp. I).

·Strains of North American common timothy, first introduced into Alaska about 1902, generally performed poorly in most areas of the Territory where it was tried. In contrast, cultivars from high latitudes in northernmost Europe, first brought into Alaska in the late 1940's, are markedly better adapted and therefore more winterhardy and productive.

·In general, winter survival was correlated with latitude of cultivar origin; cultivars from northernmost sources exhibited superior winter survival to those from

more southern origins (Exps. I, II, III, IV).

·Timothy cultivars from Norway, Iceland, Finland, and Sweden were more winterhardy than those from North America. Furthermore, cultivars from northern Norway and Iceland were more winterhardy than cultivars from southern Norway or from Finland or Sweden (Exps. I, II, III, IV).

·Considering the results of experiments in this report and other experimental tests at this location, the most winterhardy timothy cultivars for use in this area are Engmo, Bodin, and Va­BL­60 from northern Norway, and Korpa and Adda from Iceland (Exps. II, III, IV).

·Northern­adapted cultivars were more dormant in autumn after second forage harvest than mid­temperate­adapted cultivars (Exp. IV).

·The most winterhardy cultivars from North America, when well established, not winter­injured, or only moderately injured, produced total­season forage yields equivalent to Scandinavian cultivars and other extremely winterhardy, non­timothy grasses including Polar bromegrass (predominantly Bromus inermis Leyss. X B. pumpellianus Scribn.), Garrison creeping foxtail (Alopecurus arundinaceus Poir.), Nugget Kentucky bluegrass (Poa pratensis L.), and Arctared red fescue (Festuca rubra L.) (Exps. III, IV).

·After sustaining sub­lethal winter injury, marginally winterhardy timothy plants displayed a remarkable ability to recover during the growing season and to produce high second­cutting forage yields comparable with hardier cultivars (Exps. II, III).

·An insulating snow cover that remained in place during winter provided valuable protection against the stresses of lethally low air temperatures, thaw/refreeze temperature oscillations, or harmful dehydration effects of winter winds. Snow cover in the field greatly enhanced winter survival of marginally winterhardy cultivars (Exp. III).

·Even the most winterhardy timothy strains can sustain severe winter injury or even total winterkill during very stressful winters in this area (Exps. II, III).

·Winterhardy cultivars of rhizomatous grass species survived the more stressful winters better than timothy. The more exposed, superficial position of the overwintering tissues of timothy crowns, relative to the soil surface, renders even the most winterhardy cultivars more susceptible to winter injury than hardy grasses with subterranean, better protected overwintering parts (Exps. II, III, IV).

·The proportion of total­season forage yield produced in the first of two cuttings differed with origin of cultivars in the following ranking: Norway = Iceland = Finland > Sweden > Canada > USA (Exp. IV).

·Engmo, a cultivar of extreme northern origin (69o to 70oN), was more tolerant of freeze stress, stored higher pre­winter levels of food reserves, had higher concentration of dry matter in crown tissues, and survived winters at this location markedly better than Climax, of intermediate latitudinal origin (ca. 45oN), which in turn surpassed Clair in these respects, a cultivar of more southern origin (38o to 39oN) (Exps. V, VI).

·Higher seeding­year forage yields were obtained from Engmo stands planted in mid­May than 1 June; seeding­year yields from both of those planting dates were much higher than from timothy planted in mid­June (Exp. VII).

·Seeding­year harvest in late August harmed
mid­June­planted Engmo less than five later harvest dates, but that late­August forage yield was very low (Exp. VII).

·Mid­June­planted Engmo harvested later than early September in the seeding year was predisposed to considerable winter injury (Exp. VII).

·For best seeding­year forage yield, coupled with good winter survival, preliminary results suggest that winterhardy timothy should be planted no later than late May with the seeding­year harvest no later than late August (Exp. VII).

·With established stands, the highest­yielding 3­, 4­, and 5­cut treatments were lower yielding than the highest­yielding 2­cut treatments (Exps. VIII, IX).

·With Engmo timothy harvested twice per year, stands were negatively impacted (as measured by first­cut yields the following year) by progressively later second cuttings from 22 July to 21 September, the latest second­cutting date. This effect was similar with all three different dates of first cutting (10 June, 22 June, 30 June). The 21 September final cutting date also had a slight negative effect on plots harvested three or four times per year.

·With harvest in early June, height of the hidden growing points (shoot apices) in relation to cutting height was critical to rapidity of regrowth. If growing points were below cutting height, growth of tillers continued vigorously. However, if growing points were high enough to be removed in the harvested herbage, growth of those tillers ceased and regrowth developed very slowly from new basal tillers (Exps. VIII, IX).

·Far­northern­adapted timothy strains, with their abundance of basal leaves, are relatively unique among tall­growing forage grasses in being tolerant of more than two cuttings per year (unlike mid­temperate­adapted North American timothies or smooth bromegrass). In fact, their subsequent winter survival was enhanced by more than two harvests per year. More than two cuttings per year probably precludes harmful prolonged shading and deterioration of the abundance of basal leaves characteristic of those far­northern timothies (Exps. VIII, IX).

·The modest normal amount of precipitation in this area (15.56 inches annually at the Matanuska Research Farm, 10.17 inches April through September) is marginal to inadequate for realizing the full forage­production potential of timothy. Moreover, very modest precipitation during April, May, and June (normal = 0.63, 0.74, and 1.59 inches, respectively) sometimes severely curtailed the potentially heavy growth during June, especially if precipitation was below normal during the latter portion of the previous growing season (Exps. II, III, IV, VIII, IX). Supplemental sprinkler irrigation can assist in realizing the full forage­production potential of timothy in this area.