Winterhardiness of some winter wheat ( Triticiim aestivum), rye (Secale cereale), triticale (x Triticosecale) and winter barley (Hordeum vulgare) cultivars tested at six locations in Finland Leena Mömmö and Seppo Pulu Mömmö, L. & Pulli, S. 1993. Winterhardiness of some winter wheat (Tritkum aestivum ), rye (Secale cereale ), triticale (x Triticosecale ) and winter barley (Hor- deum vulgare ) cultivars tested at six locations in Finland. Agric. Sci. Finl. 2: 311-327. (Agric. Res. Centre of Finland, Inst. Plant Breed., FIN-31600 Jokioinen, Finland.) The winterhardiness of 24 winter wheat, 13 rye, 5 triticale and 11 winter barley varieties of different origins was tested at six locations in Finland in 1989-1992. The survival ability of the cultivars, their resistance to snow mould (Microdochium nivale ) and the correlations between these traits and the growth habit and growth stage were deter- mined. The trials were grouped on the basis of variety ranking, and the differences between the varieties within each group were studied by the analysis of variance. Statistically highly significant differences between varieties were found in all cases. The wintering conditions during the trials were very variable,and this brought about differences in the ranking of cultivars in different trials. In most cases the genotypic-environmental interactions could be explained by the different genetic systems controlling the toler- ance to various winter stresses and changes in their intensity. Key words; cold tolerance, frost resistance, Microdochium nivale, snow mould Introduction Winter cereals are grown mainly in temperate re- gions of the world. The ability of species to accli- mate (harden) during autumn to survive the ex- treme conditions in winter determines their north- ern limit of distribution. During the hardening pe- riod, numerous changes take place in the plant (Levitt 1972). The rates and extent of these changes depend upon both the genotype of theplant and the prevailing environmental conditions (Fowler and Gusta 1977). According to Fowler and Limin (1987), the maximum coldhardiness of the most winter hardy cultivars of barley (Hordeum vulgare L.), triticale (X Triticosecale Wittmack), wheat (Triticum aestivum L.) and rye (Secale ce- reale L.) is -19°C, -24°C, -25°C and -34°C, respect- ively. This order of coldhardiness is also reflected in their commercial cultivation areas in the Nordic countries: Denmark, Sweden, Norway, Finland and Iceland. Winter barley is grown almost only in Denmark (175,000 ha in 1993) and in Southern Sweden (10,700 ha in 1992). The winter triticale also meets its northern limit in Denmark (1,000 ha in 1993) and in Southern Sweden (19,400 ha in 1992). Winter wheat is grown up to the southern parts ofFinland (Fig. 1), and the southern and costal areas of Norway. The area of winter wheat cultiva- tion was in Denmark 610,000 ha (1993), in Sweden 235,000 ha (1992) and in Norway 33,000 ha (1993). In Finland, during the last five years the winter wheat area has varied between 46,400 ha 311 Agric. Sei. Finl. 2 (1993) https://www.c-info.fi/en/info/?token=G8PsvZJiPQ--hnpU.XNhPJb0FiBPLNICe8Mr35g.dAlpYOVA03yaxpwprLkRnC9WWDqZX4Xr_Z-Yn3MI6jBx7CNguk0V3HPZ92T5bz-FVgazlQzjl4CM3eFAhPd-YK7pgMxWFnXoPKZSGBLNXwDMN3RXGkh4m-6toI6IMoNqNU2UVtus2VWhIdB4OrcXQycVmE9fRx7ZDJU1Pm417e-SnhMmANiHjXuhyhfT3DC8Jd_MNurd1Nm32eaWe3z5nmlGHzF-kREb8azYH4a098l95D-IpeqKe88PtrQPCUOnQ_1bmMXD7tQvbmszSTSDOplljlJcz4uxi1NQBQ (1991) and 12,300ha (1992), depending on both the climatic factors and policy. The northern limit of distribution of rye is in central Finland (Fig.l). The area of rye cultivation was in Denmark 70,000 ha (1993), in Sweden 34,100 ha (1992) in Norway 2,000 ha (1993) and in Finland it has ranged be- tween 84,800 ha (1990) and 10,600 ha (1992) dur- ing the last five years. In Iceland, only some experi- ments have been made on winter cereals, but there is no commercial cultivation. Since the spring forms of species avoid the pos- sible economic losses caused by the winter dam- ages, spring barley is cultivated in all the Nordic countries but Denmark, and spring wheat exceeds winter wheat in Finland and in Norway. The higher yield level, the better drought resistance in early summer and early harvesting in autumn have, how- ever, made the winter forms very important also in the northern limits of distribution. This has urged the development of better agronomic practices for cultivating winter cereals (Andersen 1992, An- dersson 1986, Bengtsson 1986, Bruehl 1982. FOWLER et al. 1976, Gudleifsson 1986, Gusta 1986, Hänninen and Jamalainen 1968, Hether- ington et al. 1990, Jamalainen 1974, Nissinen 1986, Olvång 1992, Pohjakallio et al. 1962, Pomeroy and Andrews 1989,Pulli 1986,Smith 1986, 1987 and URVAS 1986) and also to find some new resources of winterhardiness to be utilized in developing new, more winter resistant cultivars (Andrews et al. 1986, Brule-Babeland Fowler 1987, Dvorak and Fowler 1978, Fowler et al. 1977, Hensleigh et al. 1992, Jenkins 1963, Lazar et al. 1988, Limin et al. 1985, Limin and Fowler 1984, 1986, 1988. 1991. Veisz and Rajki 1987). Although numerous sophisticated tests have been developed to measure the hardening ability and resistance of breeding material against differ- ent winter stresses, field trials are, in most cases, still used to give the ultimate evaluation of the winter hardiness of the studied lines or cultivars. In the present study, the winterhardiness of win- ter wheat, rye, triticale and winter barley varieties was tested in field trials established at six locations in Finland (Fig.l) in 1989-1992. On the basis of these results the tested cultivars were arranged ac- cording to their resistance against different winter stresses, and the suitability of the experimental sites for screening the winterhardiness of tested species was discussed. Material and methods The field trials comprised 24 (22 in 1989-90) winter wheat, 13 (II in 1989-90) winter rye, 5 winter triticale and II (10 in 1989-90) winter barley vari- eties. The varieties and their origins are listed in Tables I and 7. The field trials were carried out at four loca- tions: Anjalankoski (60°43'N, 26°48’E), Pälkäne (61°20’N, 24°13’E), Laukaa (62°20’N, 26°10'E) and Sotkamo (64°06’N, 28°20’E) in 1989-1990. In 1990-1991 and 1991-1992 trials were established also at Jokioinen (60°49’N, 23°30’E) and Mietoi- nen (60°38’N, 21°51’E) (Fig.l). Fig. 1. Locations of the field trials. 1 = Mietoinen, 2 = Jokioinen, 3 = Pälkäne, 4 =Anjalankoski, 5 = Laukaa and 6 = Sotkamo. The northern limits of winter wheat andrye cultiva- tion are also shown on the map. 312 Agric. Sd. Fin!. 2(1993) The trials were completely randomized with four replicates and the cultivars were sown in 1 m rows. The trials were sown in August and they were fertilized in autumn and in spring according to the normal practice of the experimental stations. In autumn, the growth habit of varieties was determined using a scoring system of 1 (prostrate) to 5 (erect). In autumn 1990 at Jokioinen and Mie- toinen, 10 plants of each variety were selected ran- domly from the first replicate and the number of leaves (growth stage) and the height of the plants were measured. The winter survival rate of varieties was deter- mined by counting the plants both in the autumn and in the spring soon after the snow had melted. At the same time, damage to the plants caused by snow mould (Microdochium nivale (Fr.) Samu & Hall) was rated using the scoring system of 0 (totally undamaged) to 10 (dead). The climatic data concerning the temperatures and the snow cover at the experimental sites was obtainedfrom the Monthly Reports of the Meteoro- logical Institute ofFinland. Differences in winter survival abilities between experimental varieties were studied using the ana- lysis of variance and Tukey’s studentized range test. The arcsin modification of data was done be- fore the analysis. The correlations between winter survival of va- rieties, snow mould resistance, growth habit, num- ber of leaves and height of plants were determined using the correlation analysis. The field trials were part of the Inter-Nordic "Winterhardiness" Project. The same winter wheat, rye, triticale and winter barley varieties were tested in the same years in all the Nordic countries at 17 locations. The test locations were in Denmark Tyst- ofte, Riso, Abed, Pajberg and Sejet; in Sweden: Svalöv andUppsala; in Norway: Apelsvoll, Kvitha- mar and Vågones and in Iceland: Mööruvellir. The Inter-Nordic field trial results collected by Dr Kurt Hjortsholm were kindly offered for use in this study. The data was divided into two groups on the basis of the assumed main stress factor, snow or frost, and the winter survival ofvarieties was deter- mined within each group. The correlations between the combined Inter-Nordic field test results and the overwintering results in Finland were deter- mined. Results The level of general survival of each studied spe- cies varied greatly depending on the year and ex- perimental site (Fig. 2). The variation was greater among winter wheat and winter barley varieties than among the rye and triticale varieties (Fig. 2). Winter rye was the most winter hardy species, win- ter wheat was somewhat hardier than winter triti- cale, and winter barley was inferior in this respect. Since wheat variety ’Vitus’ behaved more like spring wheat in it’s ability to harden during autumn and therefore had very low winter survival (Table 1), it was excluded from further testing. Winter wheat The field survival of winter wheat varieties at dif- ferent locations in 1989-1992 is shown in Table 1. The analysis of variance indicates that in some trials the differences between varieties were not significant (Table 1). In some cases this was due to a very mild winter period (Mietoinen 1992 and Jokioinen 1992), which caused only slight damage to the plants. Ice encasement at Anjalankoski 1991 resulted in very clear but uneven injury to the culti- vars, but the differences between varieties were obscured by the great variation between replicates. The ranges of variation within each trial are shown in Figure 2. Very significant positive cor- relations were found between all the trials in which there was a wide variation between varieties. This was obvious for Jokioinen 1991, Pälkäne 1990, Anjalankoski 1991, Laukaa 1990 and 1991 and Sotkamo 1990, 1991 and 1992. All these trials were characterized by cold winter withrather long period of snow cover, and they were pooled to form group 1. The results of this group correlated well also with all the results from Inter-Nordic trialsand with the total results from Finnish trials (Table 2). The group 2 trials were Mietoinen 1991,Pälkäne 1991, Anjalankoski 1990 and 1992 and Laukaa 313 Agric. Sei. Fin!. 2 (1993) Fig. 2. Variation in winter survival ability of winter wheat (1), triticale (2), rye (3) and winter barley (4) varieties, and total variation of each species in each of the experimental years (5). Winter wheat variety ’Vitus’ was excluded because it is similar in hardiness to spring wheats. 314 Agric. Sei. Fin!. 2(1993) Agric. Sei. Finl. 2 (1993) Table 1. Survival of winter wheat varieties (%) at four locations in 1989-1990 and at six locations in 1990-1991 and 1991-1992. The figures after the namesof test locations denote the numbers at Figure 1. The analysis of variance wasused to study the differences between varieties. nd = not done. * p < 0.05, ** p < 0.01 and *** p < 0.001. Mietoinen (1) Jokioinen (2) Pälkäne (3) Anjalankoski (4) Laukaa (5) Sotkamo (6) Variety Origin 1990 1991 1990 1991 1989 1990 1991 1989 1990 1991 1989 1990 1991 1989 1990 1991 Linna Finland 99.099.7 83.4 97,1 90.0 95.1 58.499.0 58.995.6 90.085.0 99.4 92.5 47.2 67.7 Vakka Finland 98.6100.0 83.499.4 87.596.3 38.498.8 58.394.4 93.381.7 97.9 96.8 26.478.6 Albidom 12 Russia 95.6100.0 86.999.0 72.595.2 41.3100.0 59.595.6 73.891.7 93.7 96.5 25.172.5 Frederick Canada 97.299.2 39.2100.0 81.362.9 11.482.3 52.672.0 85.855.0 88.9 65.3 6.620.5 Goertzen 5559 USA 95.6 99.1 16.092.8 58.884.0 18.099.5 42.384.6 50.0 10.0 97.175.5 14.954.5 Norstar Canada 96.5 99.5 65.2 93.8 78.888.7 23.4100.0 39.696.0 92.0 71.7 97.2 96.3 17.748.1 Skjaldar Norway 96.297.9 67.2 97.3 71.395.0 27.9100.0 69.893.8 62.558.0 99.183.7 16.979.3 Folke Sweden 97.9100.0 60.898.4 63,8 95.427.4 98.5 52.4 94.770.0 66.796.4 70.3 17.2 74.7 Holme Sweden 95.5 99.8 87.1 99.6 57.5 95.0 12.3 98.0 57.6 87.6 68.8 73.3 97.4 60.5 6.5 41.8 Walde Sweden 98,2 99.8 90.6 100.0 72.5 92.6 22.8 99.5 59.5 93.0 82.5 79.5 98.1 82.5 19.9 57.1 Hildur Sweden 91.0 99.8 47.7 93.6 55.0 89.1 16.0 100.0 44.0 87.5 45.8 50.0 98.9 56.8 7.0 38.4 Rida Norway 97.0 99.2 67.2 99.2 57.5 90.6 33.3 98.8 39.8 97.6 65.0 88.3 98.7 82.0 20.0 57.7 Solid Sweden 96.1 100.0 46.5 89.7 47.5 93.1 15.3 99.3 25.9 92.7 27.5 28.8 97.6 75.8 9.5 60.5 Kosack Sweden 96.7 99.8 79.6 97.1 80.0 96.1 24.2 99.5 69.6 93.4 78.8 50.0 99.7 90.0 11.1 75.8 Kraka Denmark 96.3 100.0 72.9 100.0 91.3 86.7 22.5 96.9 34.6 80.2 81.3 26.3 98.1 42,3 10.9 42.5 Sleipner Sweden 95.5 99.8 17.8 95.0 61,3 95.9 51.9 96.0 54.1 81.4 70.0 29.5 98.4 37.5 9.3 27.9 Urban Sweden 96.6 99.3 36.1 97.2 76,3 87.7 21.4 98.3 21.7 86.2 53.8 47.5 98.2 41.0 10.9 21.0 Gawain England 86.8 99.8 18.0 97.2 47.5 81.6 16.3 92.3 15.3 75.3 10.0 11.3 92.9 38.3 1.9 9.5 Longbow England 90.7 99.1 16.2 89.9 51.3 70.5 5.2 80.5 19.2 61.8 7.0 22.5 96.2 4,3 1.6 4.6 Apollo Germany 93.3 99.6 31.2 90.8 45.0 76.7 21.8 79.5 18.7 78.9 20.0 10.0 92.3 9.8 0.6 5.3 Vitus Denmark 2.2 3.4 0.0 3.2 0.3 0.0 0.3 0.0 10.0 0.0 0.0 0.0 0.0 4.0 0.3 0.0 Aura Finland 98.0 99.8 86.1 98.0 88.8 89.4 44.3 99.5 38.6 94.7 78.3 66.3 98.6 97.3 34.5 41.3 Mironowskaja 808 Russia 97.6 100.0 76.6 98.4 nd 84.0 19.2 nd 62.7 96.3 nd 66.0 99.0 nd 16.9 66.8 Kharkov 22 MC Ukraina 97.3 99.7 31.5 93.9 nd 97.3 24.1 nd 37.8 91.1 nd 73.3 99.7 nd 29.2 71.3 F-value 2.15** 0.80 B.6l*** 1.45 4.42*** 3.67*»* B.72*** 6.29*** 2.42** s.so*** 10.69*** 7.oo*** 2,53** 12.38*** 5.35*** 12.38*** 315 Table 2. Correlations between winter survival in the winter wheat, rye and winter barley trials, and mean winter survival in the Inter-Nordic (Total frost, Total snow, Total l-N) and Finnish trials in 1989-1992 and means of all trials. * p < 0.05, “ p