Barley response to seeding date in central Alberta - NRC Research ...

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The reduction in yield was least for Jackson, the earliest maturing cultivar tested. Late seeding ..... Holly Jensen, Deanna Runge, and Donna Westling is grate-.
Barley response to seeding date in central Alberta P. E. Juskiw and J. H. Helm Alberta Agriculture Crop Research, Field Crop Development Centre, 5030-50 St., Lacombe, Alberta, Canada T4L 1W8 (e-mail: [email protected]). Received 22 April 2002, accepted 9 October 2002. Juskiw, P. E. and Helm, J. H. 2003. Barley response to seeding date in central Alberta. Can. J. Plant Sci. 83: 275–281. Seeding date is an important factor influencing productivity of barley (Hordeum vulgare L.). When conditions are conducive to early seeding or result in delayed seeding, producers need to know how cultivars will respond to these seeding situations. In this study, five cultivars (Abee, Harrington, Jackson, Noble and Virden) registered for western Canada were studied for 4 yr (1990 to 1993) when seeded early (late April or early May), in mid-May, in late-May, or late (mid-June) at Lacombe, AB. For all cultivars, early seeding resulted in grain yield advantages of 113 to 134% of the mean site yield, while with late seeding, grain yields were reduced to 54 to 76% of the mean site yield. The reduction in yield was least for Jackson, the earliest maturing cultivar tested. Late seeding reduced the period from sowing to emergence, vegetative period, grain-filling period, time from emergence to physiological maturity, test weight, grain yield, kernel weight, and tillers per plant; and increased plant height and percent thins. Late seeding had no significant effect on phyllochron, stand establishment, scald, lodging, protein content of the grain, kernel number per spike, and spikelet number per spike. Barley responded positively to early seeding in central Alberta, but when seeding was delayed (in this study to mid-June) the early and mid-maturing six-rowed cultivars with short phyllochrons performed better than the two-rowed and late six-rowed cultivars. Key words: Hordeum vulgare L., seeding rate, phenological development, grain quality, grain yield, components Juskiw, P. E. et Helm. 2003. Réaction de l’orge à la date des semis dans le centre de l’Alberta. Can. J. Plant Sci. 83: 275–281. La date des semis influe considérablement sur le rendement de l’orge (Hordeum vulgare L.). Quand les conditions autorisent des semis hâtifs ou retardent ces derniers, il est essentiel de savoir comment les cultivars réagiront. Dans le cadre de cette étude, les auteurs ont examiné cinq cultivars (Abee, Harrington, Jackson, Noble et Virden) homologués pour l’ouest du Canada pendant quatre ans (de 1990 à 1993) et semés hâtivement (fin avril ou début mai), à la mi-mai, à la fin de mai ou tardivement (mi-juin) à Lacombe (Alberta). Les semis hâtifs augmentent le rendement grainier de tous les cultivars de 113 à 134 % comparativement au rendement moyen à cet endroit tandis que les semis tardifs le diminuent de 54 à 76 %. La baisse de rendement était la moins forte pour Jackson, le cultivar le plus précoce. Les semis tardifs réduisent le laps de temps entre la mise en terre et la levée, la période de croissance, la période de remplissage du grain, le laps de temps de la levée à la maturité physiologique, le poids spécifique, le rendement grainier, le poids de l’amande et le nombre de talles par plant; ils augmentent la hauteur du plant et le pourcentage d’éclaircissage. Les semis tardifs n’ont aucune incidence sensible sur le phyllochrone, l’établissement du peuplement, la tache pâle, la verse, la teneur en protéines du grain, le nombre de grains par épillet et le nombre d’épillets par épi. L’orge réagit bien à des semis hâtifs dans le centre de l’Alberta, mais quand on reporte ces derniers (jusqu’à la mi-juin dans le cas présent), les cultivars à six rangs précoces et à maturité moyenne se caractérisant par un court phyllochrone donnent de meilleurs résultats que les orges à deux rangs et à six rangs tardives. Mots clés: Hordeum vulgare L., densité des semis, phénologie, qualité du grain, rendement grainier, composantes

Date of seeding can have a major effect on variety performance. McFadden (1970) found that Conquest barley had better grain yield potential than Olli under late-seeding conditions at Lacombe, AB. Conquest had mid-season maturity versus Olli’s early maturity. Based on McFadden’s work, it became the recommendation in Alberta that in late seeding conditions producers should plant a variety with mid-season maturity. While J. Christensen and R. I. Wolfe (1985, unpublished data) found significant yield reductions occurred for all barley cultivars that they tested when sown in late June at Beaverlodge, AB, the highest yields with early June seeding occurred for the early maturing cultivars Otal, Olli and BT653Y. For Conquest, Bonanza, Galt, Melvin, Johnston, Norbert and Betzes highest yields occurred with the late May seeding; for Elrose, Fairfield and Klages, with the early May seeding; and for Gateway 63,

with all three early dates of seeding. In earlier work, Christensen and Wolfe (1980–1983, unpublished data) found that early seeding was most favourable for all barley cultivars studied, but Olli responded best to early June seeding. The general response to seeding date for both spring and winter barley is reduced grain yields with late seeding (Fedak and Mack 1977; Baker and Gebeyehou 1982; Duczek and Piening 1982; Ciha 1983; Frank et al. 1992; Koz l⁄ owska-Ptaszy´nska 1993; Weston et al. 1993; Conry 1995; de Ruiter and Brooking 1996). Duczek and Piening (1982) found that the reduction in yield with late seeding Abbreviations: GDD, growing degree days; GS, growth stage; Tm, daily mean temperature 275

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was not associated with common root rot [caused by Cochlibolus sativus (Ito and Kurib.) Drechsl. Ex Dastur and Fusarium spp.] or plant establishment (plant number per unit area). Reduced yields with late seeding have been associated with reduced test weight (Ciha 1983), spikes per unit area (Koz l⁄ owska-Ptaszy´nska 1993), grains per spike (Koz l⁄ owska-Ptaszy´nska 1993; de Ruiter and Brooking 1996), percent plump kernels (Weston et al. 1993), and kernel weight (Koz l⁄ owska-Ptaszy´nska 1993; Weston et al. 1993; de Ruiter and Brooking 1996); and with higher grain nitrogen content (Weston et al. 1993; Conry 1995) and percent screenings or thins (Conry 1995). The objectives of this study were: (1) to determine the response of barley cultivars, differing in maturity, to date of seeding in central Alberta; (2) to evaluate if an optimum or threshold seeding period could be determined; and (3) to determine the association of specific traits with response to seeding date. MATERIALS AND METHODS Trials were conducted for 4 yr (1990 to 1993) at Lacombe, AB (Penhold Loam, orthic Black Chernozem). The test was set up as a variant of the split plot design with cultivars as main plots, and date of seeding applied in strips across all main plots in each of the four blocks (Cochran and Cox 1957). Cultivars and seeding dates were randomized in each of the four blocks in each of the 4 yr. The five spring barley cultivars selected for study covered the range of maturity classifications for barley grown in western Canada (Table 1). Each year these cultivars were planted at four seeding dates: early (late April or early May), normal (midMay and late May), and late (mid-June, Table 2). Soil samples for fertility testing of N, P and K were collected in the fall of the year prior to planting. Based on soil test results, fertilizer to meet high yield recommendations was incorporated prior to seeding or applied with the seed in 1991, 1992 and 1993 (Table 2). In 1990, fertilizer met the minimum recommendation for average grain yield. Prior to the 1990 test, the field had been planted to a winter cereal; in 1991 to a spring cereal taken for silage and in 1992 and 1993 to peas (Pisum sativum L.) plowed in as green manure. Plots were eight rows wide with a length of 4.6 m and spacing of 0.14 m. Plots were trimmed to 2.7 m prior to final harvest. Based on pre-planting germination tests and 1000kernel weights, seeding rate was 200 viable seeds m–2. Weed control was conducted as required using recommended broadleaf herbicides and hand weeding. All rows of the plot were cut by hand shortly after they had reached physiological maturity. Material was bagged and hung to dry prior to threshing with a stationary combine. This method of harvesting was used to prevent shattering losses of early maturing material. Grain yields were determined at 10% moisture on a dry weight basis. Mean grain yield was determined for the site each year; and yield on a plot basis was determined as a percentage of this mean. Emergence was determined as days and growing degree days [GDD = Σ(Tm°C > 0), where Tm = daily mean temperature] after sowing; while anthesis and physiological maturity were determined as days and GDD after emergence.

Emergence was determined in 1991, 1992 and 1993 only. Anthesis [the central florets of the head having shed their pollen, GS 61 (Lancashire et al. 1991)] and physiological maturity (loss of green colour from the peduncle corresponding to approximately 30% kernel moisture content, GS 87) were based on 50% of the plot having attained the stage. Vegetative period was determined as the number of days and GDD accumulated from emergence to anthesis. Grain-filling period was determined as the number of days and GDD accumulated from anthesis to physiological maturity. Five plants per plot were marked with stakes and plastic tags early in the growing season and assessed for Haun (1973) growth stage twice a week throughout the growing season. Haun stage was regressed against GDD, and phyllochrons, the period between emergence of consecutive Haun stages, were determined as the inverse of the slope of the regression equation. The linear regression was felt to adequately fit the data as the R2 for all equations (based on five plants per plot) was between 0.92 and 0.99. Weather data (temperature, precipitation) were measured at an onsite weather station using a LI-1000 DataLoggerRTM (LI-COR, Lincoln, NE). Scald [causal agent Rhynchosporium secalis (Oud.) J. J. Davis] and lodging were rated on a visual basis using a 0–9 scale [0 = no disease/lodging; 9 = severe disease/lodging (both to area of plot affected and degree of plant damage)] shortly after anthesis in 1991, 1992 and 1993 only. Height was measured on a plot basis. Test weight was determined using a 550-mL sample per plot. Kernel weight was determined using a 200-kernel sample per plot. Percent thins was determine by running a 200-g sample per plot for 1 min (72 shakes) through a slotted screen with mesh size of 0.22 cm × 1.91 cm. Protein content was determined by near-infrared spectroscopy as described by Jedel and Helm (1992). Ten spikes per plot were randomly picked prior to harvest and used to determine spikelet number per spike and kernel number per spike. Tiller number was counted near anthesis on two 0.5-m rows per plot. Spikelet, kernel, and tiller numbers were determined in 1991, 1992, and 1993 only. Stand establishment was measured as plant numbers m–2, determined at the two- to three-leaf stage on three 0.5-m rows per plot in 1990, 1992, and 1993. Data were analyzed using PROC MIXED of SAS Version 8.1 (SAS Institute, Inc. 1999) with cultivars and seeding dates treated as fixed effects in the mixed model; all other terms involving years, blocks, and strips were treated as random effects that were combined for significance testing with the Satterthwaite option in SAS (Littell et al. 1996; SAS Institute, Inc. 1999). Means were calculated using the LSMEANS options of PROC MIXED (SAS Institute, Inc. 1999). Least significant differences were calculated based on the standard error from the mixed analyses, only when the effect was significant (P < 0.05) based on the F-test (Steel and Torrie 1980). Using the CONTRAST option of PROC MIXED (SAS Institute, Inc. 1999), the two-rowed cultivars were compared with the six-rowed cultivars, and linear and quadratic functions were fit to the seeding dates (Littell et al. 1996).

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Table 1. Description of five spring barley cultivars used in this study (Source of information: Alberta Agriculture 1993) Cultivar

Breeding Institute

Abee Harrington Jackson Noble Virden

Field Crop Development Centre, Lacombe, AB Crop Development Centre, Saskatoon, SK Agriculture and Agri-Food Canada, Beaverlodge, AB Field Crop Development Centre Lacombe, AB Agriculture and Agri-Food Canada, Brandon, MB

zPlus

Row-type

Quality class

Two Two Six Six Six

Feed Malt Feed Feed Feed

Maturity class Mid-maturing (+1 d)z Mid-maturing (97 d) Early maturing (-5 d) Mid-maturing (+1 d) Late maturing (+3 d)

or minus Alberta provincial average maturity for Harrington.

Table 2. Seeding dates and fertilizer application for date of seeding test at Lacombe, AB, from 1990 to 1993 Pre-plant incorporated Nitrogenz

Seeding date Year

Early

Mid-May

Late May

Late

1990 1991 1992 1993

3 May 1 May 1 May 30 April

16 May 15 May 16 May 14 May

29 May 29 May 29 May 28 May

15 June 11 June 12 June 11 June

Phenological Development The interaction of cultivar × seeding date was not significant for any of the developmental traits measured (Table 3). Therefore this diverse group of spring barley cultivars had similar phenological reactions to seeding date in the central Alberta environment. The linear effect of seeding date on phenological development was often significant (Table 3). Late seeding reduced the period from sowing to emergence, vegetative period, grain-filling period, and time from emergence to physiological maturity. Virden had the longest period from sowing to emergence at 128 GDD and a long vegetative period but had a intermediate phyllochron of 72 GDD per Haun stage (Table 3). Jackson had the shortest phyllochron at 66 GDD per Haun stage, rapid emergence, and the shortest vegetative period. Noble also had a short phyllochron at 67 GDD per Haun stage. Abee and Harrington had the longest phyllochrons of 76 GDD per Haun stage and similar phenological development. All cultivars had similar grain-filling periods. Virden was late maturing because of its slow early growth and, although not statistically different than the other cultivars, due to its longer grain-filling period. Jackson was early maturing because of its rapid early growth and short phyllochron. Abee, Harrington, and Noble, all classed as midmaturing (Table 1), had intermediate periods of vegetative growth (Table 3). Agronomic and Disease Traits The interaction of cultivar × seeding date was not significant for the agronomic and disease traits measured (Table 4). As for phenological development, agronomic response to seeding date was similar for this diverse group of spring barley cultivars. No significant effects of seeding date on stand establishment, scald, or lodging were found (Table 4). This finding supports the finding by Duczek and Piening (1982)

Nitrogenx

P2O5

(kg 12 77 14 11

P2O5x

ha–1)

27 27 39 56

zIn 1990 to 1992, nitrogen was applied as urea (46-0-0) and in 1993 as ammonium phosphate (10-50-0) yIn 1990 to 1992, phosphorus was applied as triple superphosphate (0-45-0) and in 1993 as ammonium phosphate xA 50:50 blend of ammonium phosphate (12-50-0) and potassium chloride (0-0-60).

RESULTS AND DISCUSSION

Applied with the seed

y

None None None 7

None None None 56

(10-50-0).

that late seeding date did not affect stand establishment. The mean plant counts in the 3 yr that counts were made were 205, 183 and 273 in 1990, 1992 and 1993, respectively, giving a slightly higher mean plant stand than the target (Table 4). Plant height increased from the early seeding to the late May seeding, leading to an overall significant linear effect of seeding date on height (Table 4). Heights increased despite a reduction in vegetative period. All cultivars were susceptible to the scald pathogen, so the lack of cultivar effect on this trait was expected (Table 4). Of the cultivars tested, Jackson was the most prone to lodging and Virden was the least (Table 4). While Jackson was given a good rating for lodging resistance (Alberta Agriculture 1993), this rating was relative to other early maturing varieties available in the late 1980s that were very prone to lodging. Jackson was the shortest cultivar and Virden the tallest (Table 4). Grain Quality As for the phenological and agronomic traits measured, the grain quality traits measured in this study were not significantly affected by the interaction of cultivar × seeding date (Table 5). Seeding date effect was not significant except for its linear effect on test weight and percent thins (Table 5). Late seeding resulted in lower test weights. Ciha (1983) found that seeding date effects on test weight depended upon genotype and year, but tended to decline with late seeding. The percent thins increased as seeding date was delayed (Table 5) consistent with the findings of Conry (1995). Although seeding date had no significant effect on the length of the grain-filling period measured in days, there was a significant linear effect of seeding date on GDD for the grain-filling period (Table 3), and this reduced period may have meant less time for accumulation of assimilate for grain filling, resulting in increased percent thins and reduced test weight.

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Table 3. Effects of cultivar and seeding date on phenological development and phyllochrons of five barley cultivars grown in central Alberta Sowing to emergence Treatment

Days

GDDy

Vegetative period Days

Physiological maturityz

Grain-filling period

GDD

Cultivar (C) Two vs. Six rowed Date of seeding (D) Linear Quadratic C×D

** * NS * NS NS

** * NS NS NS NS

** ** NS * NS NS

Significance ** ** NS NS NS NS

Abee Harrington Jackson Noble Virden LSD0.05

10 10 10 10 11 1.4

116 121 115 122 128 12

47 45 43 45 47 2.9

Cultivars 662 633 592 634 661 35.5

Early May Mid-May Late May Mid-June LSD0.05

13 11 9 7 NS (3.2z)

141 119 116 106 NS

48 46 45 43 NS (4.4z)

Phyllochron

Days

GDD

Days

GDD

GDD

NS NS NS NS NS NS

NS NS NS * NS NS

* NS * ** NS NS

* NS NS * NS NS

** ** NS NS NS NS

40 39 40 41 43 NS

607 609 610 628 645 NS

87 85 82 86 90 7.2

Date of seeding 632 44 646 40.8 636 40 633 36 NS NS

682 638 627 531 NS (110z)

92 87 85 79 8.8

1269 1242 1202 1262 1305 54.8 1314 1283 1262 1164 NS(89.9z)

76 76 66 67 72 3.4 72 70 70 73 NS

zFor comparison of linear response to seeding date. xGDD = growing degree days = Σ(T °C > 0), where m

Tm = daily mean temperature. *, **, NS Significant at P < 0.05, P < 0.01 or not significant, respectively. Table 4. Effects of cultivar and seeding date on disease and agronomic traits of five barley cultivars grown in central Alberta Treatment

Stand establishment Scald Lodging (plants per m2) (1–9 scale)

Height (cm)

Cultivar (C) Two vs. Six rowed Date of seeding (D) Linear Quadratic C×D

NS NS NS NS NS NS

Significance NS * NS NS NS NS NS NS NS NS NS NS

Abee Harrington Jackson Noble Virden LSD0.05

220 219 210 226 227 NS

3.1 3 2.6 2.5 2.8 NS

1.4 1.1 1.6 0.8 0.6 1.1

95 96 89 103 107 13.5

Early May Mid-May Late May Mid-June LSD0.05

220 222 217 223 NS

Date of seeding 3.2 1.2 2.7 1.1 2.7 1.7 2.6 0.4 NS NS

93 97 103 99 14.6

** * * ** * NS

Table 5. Effects of cultivar and seeding date on grain quality traits of five barley cultivars grown in central Alberta Treatment

Test weight (kg m–3)

Percent thins

Protein content (%)

** ** NS * NS NS

Significance NS NS NS * NS NS

** NS NS NS NS NS

Abee Harrington Jackson Noble Virden LSD0.05

624 611 621 582 568 30.5

Cultivars 12.5 10.8 10.5 16.6 11.9 NS

12.6 12.3 13.1 12.3 11.8 1.02

Early May Mid-May Late May Mid-June LSD0.05

631 625 605 543 NS(51.5z)

Date of seeding 6.2 10 11.8 24.9 NS(13.15z)

12.4 12.3 12.5 12.6 NS

Cultivar (C) Two vs. Six rowed Date of seeding (D) Linear Quadratic C×D

Cultivars

*, **, NS Significant at P < 0.05, P < 0.01 or not significant, respectively.

zFor comparison of linear response to seeding date. *, **, NS Significant at P < 0.05, P < 0.01 or not significant, respectively.

Although Fedak and Mack (1977), Weston et al. (1993), and Conry (1995) found that late seeding resulted in higher protein content of the grain, no effect of seeding date on protein content was found in our study (Table 5). This lack of response was unexpected based on the effects of seeding

date on percent thins and test weight. It was expected that these reductions would have led to an increase in grain protein concentration (lack of starch dilution effect). Therefore, there could have been a reduction in protein production or transport in the late-planted material.

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Fig. 1. Response of five barley cultivars grown at Lacombe, AB, to four seeding dates, averaged over four growing seasons (LSD0.05 = 2.4%), on a percentage basis of mean site yield in each year (1990 = 6.10 t ha–1; 1991 = 6.94 t ha–1; 1992 = 6.11 t ha–1; 1993 = 7.18 t ha–1).

Table 6. Effects of cultivar and seeding date on grain yield and yield components of five barley cultivars grown in central Alberta Grain yield (t ha–1)

Kernel weight (mg)

Cultivar (C) Two vs. Six rowed Date of seeding (D) Linear Quadratic C×D

* ** ** ** NS NS

* * * ** NS NS

Abee Harrington Jackson Noble Virden LSD0.05

5.93 6.05 6.89 7.01 7.01 0.936

42.3 42.4 41.3 37.7 41.9 3.1

Early May Mid-May Late May Mid-June LSD0.05

7.93 7.7 6.49 4.2 1.291

45.1 43.7 40.5 35.1 4.86

Treatment

Kernel number Spikelet number (no. per spike)

Tiller number (no. m–2)

Significance ** ** NS NS NS NS

** ** NS NS NS NS

** ** NS * NS *

23.7 24.4 53.9 51.8 53.6 3.1

25.4 27.5 60.7 61.5 64 3.32

470 426 248 287 242 30.9

41.2 41.9 42.7 40.1 NS

47.6 47 49.6 47.1 NS

Cultivars

Date of seeding 374 346 304 314 NS(38.5z)

zFor comparison of linear response to seeding date. *, **, NS Significant at P < 0.05, P < 0.01 or not significant, respectively.

Percent thins is an indication of kernel fill and potential dockage. It is generally higher for six-rowed cultivars than two-rowed cultivars, due to a size limitation of the lateral kernels in six-rowed cultivars (Voltas et al. 1998). However, in this study, no significant difference in percent thins was found between the six- and two-rowed cultivars (Table 5). No premium is given for protein content in feed barley, but for malting grade, protein content must fall between preset limits. For two-rowed malting barley, such as Harrington, a protein content ranging from 10.5 to 12.5% is desired by the industry

(Brewing and Malting Barley Research Institute 1996), and average protein for Harrington in our study was 12.3 (Table 5). Jackson tended to have high protein content while Virden had low protein content (Table 5). Grain Yield and Yield Components Grain yields were reduced with the late seeding date for all cultivars studied (Fig. 1, Table 6). These findings support earlier studies done in other environments that indicated late seeding of spring barley results in reduced grain yields

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(Fedak and Mack 1977; Koz l⁄ owska-Ptaszy´nska 1993; Weston et al. 1993). Lower grain yields may have been due to shorter vegetative and grain-filling periods (Table 3) resulting in lower kernel weights and tiller numbers per plant (Table 6). When effects of seeding date were compared between cultivars, delayed seeding resulted in yield losses for all cultivars; however, Jackson was generally the least affected (Fig. 1). Noble also tended to be more tolerant of late seeding than the other cultivars. Both Jackson and Noble had short phyllochrons that under the shortened growing period for the late-seeded material may have enabled them to be more tolerant to the late seeding. While the result for the mid-maturing cultivar Noble supports McFadden’s (1970) finding, the response for the early Jackson was not as McFadden found for the early Olli but was similar to the findings of Christensen and Wolfe (unpublished). All cultivars had a positive yield response to early seeding also supporting the unpublished findings of Christensen and Wolfe. Late seeding resulted in substantially lower kernel weights (Table 6). Weston et al. (1993) also found that late seeding of barley resulted in lower kernel weight. Kernel numbers per spike and spikelet number per spike were not affected by seeding date, and cultivar differences were due to the differences between six- and two-rowed types for these traits (Table 6). The cultivar × seeding date effect on tiller numbers was significant with tiller numbers being significantly lower for Abee and Harrington with the late May or mid-June seeding dates than the two early dates; but date having no significant effect on tiller numbers for the sixrowed cultivars (data not shown). As expected for this diverse group of barley genotypes, the two-rowed cultivars had lower grain yields, higher kernel weights, lower kernel and spikelet numbers per spike, and higher tiller number per m2 than the six-rowed cultivars (Table 6). The two-rowed cultivars tended to have a higher ratio of kernels to spikelets indicating better fertility than the six-rowed cultivars. We have found in the barley breeding program at Lacombe that a late-seeded nursery is beneficial in the selection of lines that perform well across a range of planting dates. It is important to remember when studying cultivars with a wide range of maturity that late harvest may result in shattering of the early-maturing cultivars. CONCLUSION When seeding in central Alberta was delayed to mid-June for the wide spectrum of barley genotypes tested, yield and quality of the grain were reduced. Of the specific cultivars tested, Jackson, an early maturing six-rowed feed barley had the least yield loss when planted late. Noble, a mid-maturing six-rowed feed barley, was also better able to tolerate late seeding by maintaining yield better than the late sixrowed cultivar, Virden, or the two-rowed cultivars, Abee and Harrington. Late seeding reduced the period from sowing to emergence, vegetative period, grain-filling period, time from emergence to physiological maturity, test weight, grain yield, kernel weight and tillers per plant; and increased plant height and percent thins. Late seeding had no signifi-

cant effect on phyllochron, stand establishment, scald, lodging, protein content of the grain, kernel number per spike, and spikelet number per spike. Based on these tests, seeding barley in mid-June for grain production could not be recommended in central Alberta. However, when faced with late seeding, planting cultivars with short phyllochrons such as Jackson and Noble could reduce production losses. Further research is needed to confirm that the ability to tolerate late seeding is related to short phyllochrons. New cultivars should be evaluated for response to late seeding before any recommendations are made. ACKNOWLEDGEMENTS The technical assistance of Carroll DePape, Dave Dyson, Holly Jensen, Deanna Runge, and Donna Westling is gratefully acknowledged. Our thanks also to Dr. Robert (Bob) Wolfe for discussions on the effects of seeding date on barley and the Beaverlodge data, and to Dr. William (Bill) Legge, Murray McLelland, and Dr. Joseph Nyachiro for their valuable critique of our work. Alberta Agriculture. 1993. Varieties and cereals of oilseed crops for Alberta – 1993. Agri-fax. Agdex 100/32. AB Agric., Edmonton, AB. Baker, R. J. and Gebeyehou, G. 1982. Comparative growth analysis of two spring wheats and one spring barley. Crop Sci. 22: 1225–1229. Brewing and Malting Barley Research Institute. 1996. Quality factors in malting barley. BMBRI, Winnipeg, MB. Ciha, A. J. 1983. Seeding rate and seeding date effects on spring seeded small grain cultivars. Agron. J. 75: 795–799. Cochran, W. G. and Cox, G. M. 1957. Experimental designs. 2nd ed. John Wiley & Sons, New York, NY. 611 pp. Conry, M. J. 1995. A note on the effect of sowing date and fertiliser nitrogen on the yield, grain nitrogen and screenings content of spring-sown malting barley. Ir. J. Agric. Food Res. 34: 69–73. de Ruiter, J. M. and Brooking, I. R. 1996. Effect of sowing date and nitrogen on dry matter and nitrogen partitioning in malting barley. N.Z. J. Crop Hortic. Sci. 24: 65–76. Duczek, L. J. and Piening, L. J. 1982. Effect of seeding depth, seeding date and seed size on common root rot of spring barley. Can. J. Plant Sci. 62: 885–891. Fedak, G. and Mack, A. R. 1977. Influence of soil moisture levels and planting dates on yield and chemical fractions in two barley cultivars. Can. J. Plant Sci. 57: 261–267. Frank, A. B., Bauer, A. and Black, A. L. 1992. Effects of air temperature and fertilizer nitrogen on spike development in spring barley. Crop Sci. 32: 793–797. Haun, J. R. 1973. Visual quantification of wheat development. Agron. J. 65: 116–119. Jedel, P. E. and Helm, J. H. 1992. Agronomic response of sixrow barley cultivars to supplemental fertilization and late-season fungicide treatments. Can. J. Plant Sci. 72: 1121–1130. Koz l⁄ owska-Ptaszy´nska, Z. 1993. Changes in the structure and architecture of plant canopy of two- and six-rowed spring barley cultivars as influenced by seeding date. IUNG, Pu⁄lawy. 102: 53–64. Lancashire, P. D., Bleiholder, H., van den Boom, T., Langelüddeke, P., Strauss, R., Weber, E. and Witzenberger, A. 1991. A uniform decimal code for growth stages of crops and weeds. Ann. Appl. Biol. 119: 561–601. Littell, R. C., Milliken, G. A., Stroup, W. W. and Wolfinger, R. D. 1996. SAS System for Mixed Models. SAS Institute Inc., Cary NC. 633 pp.

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