Maataloustieteellinen Aikakauskirja Vol. 59: 51—55, 1987 Spring wheat mixtures in northern crop production: Quality characteristics H. SALOVAARA 1 and R. KARJALAINEN 2 1 Department of Food Chemistry and Technology 2 Departments of Plant Pathology and Plant Breeding University of Helsinki, SF-00710 Helsinki, Finland Abstract. Mixtures of two or three spring wheat cultivars (Tähti/Kadett; Tähti/Kadett/ Tapio) were grown on experimental plots and the resulting crops were analyzed by selected procedures to indicate breadmaking quality. The quality tests included tests on the protein con- tent, sedimentation values and rheological properties of doughs. Comparisons between mixtures and the means of pure components did not show any definite variations in terms of major quality characteristics. The quality of mixtures appears to be predictable from the performance of the pure components. The present study suggests that mixtures give equal quality compared with pure stands. Index words: spring wheat, cultivar mixtures, breadmaking quality. Introduction The yield and quality of a wheat crop are both governed by genetic and environmental factors. In a hard climatic region used for wheat production, such as Finland, yearly fluctuations in the quantity and quality of the crop are a major problem. Genotype-environ- ment interactions are strongly involved in these variations. Therefore, there is a hypo- thesis that the use of mixtures of cultivars might help in stabilizing the crop in terms of yield, disease resistance, or end-use properties. Available data (Marshall and Brown 1973, Wolfe 1985) suggest that cultivar mixtures can improve yield stability by reducing the genotype-environment interaction and by im- proving crop resistance to plant pathogens. However, very little attention has been paid to the assessment of whether mixtures can af- fect crop quality. In the present study we have grown mix- tures of two or three spring wheat cultivars over two years in small scale field trials in order to obtain an idea of the potential of mixed cropping with respect to wheat quality. The purpose of the study was to record wheth- 51 JOURNAL OF AGRICULTURAL SCIENCEIN FINLAND https://www.c-info.fi/en/info/?token=9Fla-nt3mk2I0-qS._xusz2n6y0_UqIGYAVMflA._nDeW6ZyhkaTkCZ9D0dtg6NtJHHCmNhG36wDCfUjyJiqv7syKkbNe4u3mFaZr0yEs9il4Wvm-PPIn-yG9FGTcn8soLNWLXb9SOqO2gNl_Inq_nGVawzdBrUUknC-XzG3M3u2HHj55FoLC_oBmtVb4ENe6DFt3WQ45s9E2Cq7259daMfWNOGvedD3cNpA er the quality characteristics of wheat cultivat- ed in mixtures are different from those grown separately. Materials and methods The data presented in this study are based on field trials carried out at the experimental farm of the University of Helsinki (Viikki) in the years 1984 and 1985. Our test cultivars in- cluded two comparatively new high yielding cultivars, Kadett and Tapio, and an older, poor yielding and disease susceptible cultivar, Tähti, which in turn is characterized by a high protein content and good gluten quality (Mustonen et ai. 1986, Salovaara 1986). The field experiment was laid out in a randomized block design with three replica- tions in 1984 and four replications in 1985. Plot size was 10 m 2, and 80 kg N levels per hectare were used. Observations of the growing wheats were made and no major dis- ease infection was detected. Two component 50/50 mixtures involving Tähti and Kadett were used in 1984 and 1985. In the latter year three components Tähti, Tapio and Kadett, were also grown in equal amounts. Harvested wheat samples were dried to 13— 14 % moisture. Hectolitre weight, 1000 ker- nel weight and the falling number of the sam- ples were determined according to standard procedures applied in Finland (Anon 1979). Results of these measurements and the yields obtained are given on a 15 % moisture basis. Subsamples of 200 g were separated and milled to about 67—70 °7o extraction on the Brabender Junior laboratory mill. This mill produces flours with ash contents of about 0.6—0.7 % (dm). The flour samples were used in sedimentation tests and mixograph mea- surements. Protein content of the samples was deter- minedby the near infra-red reflectance (NIR) procedure (Anon 1983) using an Inframatic 8100 apparatus (PerCon Prufgeräte GmbH, Hamburg, FRG). Sedimentation values were determined by the standard procedure (Anon 1978). SDS-sedimentation volumes were de- termined using the procedure described by Axford et al. (1979). Water absorption capacities of the flour samples were measured using a centrifuge method described by Sosulski (1962). He reported on a high correlation between cen- trifuge absorption and farinograph absorp- tion. In the present study, absorption record- ed in the centrifuge test was used in mixograph measurements. In the present study we have assumed thatmixogram determinations made with adjusted water additions would provide more information on rheological properties of dough than mixograms made with a constant water addition. Mixograms were determined by a standard procedure (Anon 1983) using a 10 mg mixer. All analytical measurements were made in duplicate using samples from two replicative treatments. Means of the four individual mea- surements are given in the tables. Results and discussion The data reported in this study suggest (Table 1) that most of the agronomical char- Table 1. Quality characteristics of wheats cultivated in combinations and separately. Quality Experiment A 1 (1984) Experiment A 2 (1985) Experiment B (1985) characteristics of grains Tähti Kadett Mixture Tähti Kadett Mixture Tähti Kadett Tapio Mixture 100 % 100 % 50/50 100 % 100 % 50/50 100 % 100 % 100 % 33/33/33 exp. obs. exp. obs. exp. obs. Yield kg/ha 4980 6630 5805 5690 2820 3617 3219 3207 2872 3668 3257 3266 3423 1000 k. weight g 39.741.7 40.738.9 33.738.5 36.137.7 36.439.4 39.638.5 37.6 Hectolitre wt kg 78.176.9 77.577.5 78.577.5 76.877.6 78.1 Falling number s 282 197 240 214 404 279 342 391 304 275 255 278 250 52 acteristics in mixtures appear to be close to the mean values of their pure components. In both series of experiments Kadett was most and Tähti least productive. Statistically no characteristics of the mixtures differed signif- icantly from the means of their pure com- ponents. Thus, the data from Table 1 do not suggest any definitesynergistic improvements in yield or quality of mixtures as related to the means of their pure components. Table 2 shows the inherent quality char- acteristics of the samples from various treat- ments. In accordance with the data shown in Table 1, the quality of mixtures appears to be Fig. I. Mixograms of spring wheat cultivars and their two and three component mixtures. Components in equal amounts. 53 Table 2. Inherent quality characteristics ofwheat and flours from grains cultivated in combinations and separately Quality Experiment A 1 (1984) Experiment A 2 (1985) Experiment B (1985) characteristics Tähti Kadett Mixture Tähti Kadett Mixture Tähti Kadett Tapio Mixture 100 % 100 % 50/50 100 % 100 % 50/50 100 % 100 % 100 % 33/33/33 exp. obs. exp. obs. exp. obs. Seed protein % 13.6 12.4 13.0 13.1 12.7 12.2 12.5 12.5 13.3 12.7 13.3 13.1 13.2 Sedim. value ml 33 41 37 30 41 44 43 37 43 43 33 40 36 SDS-sedim value ml 59 73 66 68 77 85 81 84 74 85 76 78 79 Centrifuge 61.8 57.0 59.4 60.0 63.5 59.2 61.4 61.2 63.8 59.6 60.5 61.3 60.6 absorption % Mixograph characteristics Area u. curve cm/cm2 151 152 152 164 121 133 127 163 136 109 142 129 134 Peak time min 3.0 4.0 3.5 3.5 5.0 4.5 4.8 4.0 4.5 4.5 4.0 4.3 4.0 Peak height mm 59 58 59 65 55 61 58 60 57 62 59 59 63 Curve ht at 7 min 52 55 54 59 52 56 54 57 54 59 54 56 59 in a range that could be anticipated from simple arithmetical calculations, which are confirmed by mixograms of pure stands and their mixtures (Fig. 1). Thus we did not find evidence of any definite quality improvement in mixtures compared with the means of the pure components. These observations support recent data by Sammons and Baenziger (1985), who also reported that cultivar mix- tures of winter wheat had no effect on the mil- ling and baking quality in relation to pure stands. Furthermore, Wolfe et al. (1981) re- ported that the grain quality of barley mix- tures differs little from the mean of the com- ponents in terms of protein content and malt extract. Consequently, it appears that predic- tion of the grain quality of mixtures on the basis of pure components is simpler than that of disease resistance or performance of yield. The present study was carried out in cir- cumstances where experimental plots were not affected by wheat diseases. Flowever, our recent studies (Karjalainen and Salovaara 1986) suggest that Septoria nodorum can af- fect wheat quality. As it is well-known (Wolfe 1985) that growing mixtures is beneficial par- ticularly under disease stress conditions, more attention should be paid to studying whether cultivar mixtures could also improve the quality of wheat under disease stress com- pared to pure stands. Acknowledgements. The technical assistance of Miss Taina Kuisma and Mr. Petri Jokinen in the analytical measurements is appreciated. References Anon, 1983. Approved methods of the AACC. Bth ed., Methods 39—10 and 54—40. American Association of Cereal Chemists, Inc. St. Paul, Minn., USA. Anon, 1978. Standard methods of the ICC. International Association for Cereal Chemistry. Vienna. Verlag Moritz Schäfer, Detmold, FRG. Anon, 1979. Viljakauppaopas. Viljantutkimustoimikun- ta. Helsinki. Axford, D.W.E., Macdermott, E.E. & Redman, D.G. 1979. Note on the sodium dodecyl sulfate test of breadmaking quality: comparison with Pelshenke and Zeleny tests. Cereal Chem. 56: 582—584. Karjalainen, R. & Salovaara, H. 1986. Effect of severe infection with Septoria nodorum on spring wheat quality. (Manuscript 1986). Marshall, D.R. & Brown, A.D.H. 1973. Stability of performance of mixtures and multilines. Euphytica 22: 405—412. Mustonen, L., Pulli, S. Rantanen, O. & Mattila, L. 1986. Virallisten lajikekokeiden tuloksia 1978—1985. 54 Maatalouden tutkimuskeskus. Tiedote 5/86, Jokioinen, Finland, Salovaara, H. 1986. Wheat and flour quality related to baking performance in industrial French bread proces- ses. Acta Agric. Scand. 36: 387—398. Sammons, D.J. & Baenziger, P.S. 1985. Performance of four winter wheat cultivars in blended populations. Field Crops Research 10: 135—142. Sosulski, F.W. 1962. The centrifuge method for deter- mining flour absorption in hard red spring wheats. Cereal Chem. 39: 344—350. Wolfe, M.S. 1985. The current status and prospects of multiline cultivars and variety mixtures for disease resistance. Ann. Rev. Phytopathol. 23: 251 —273. Wolfe, M.S., Barret, J. & Jenkins, J.E. 1981. The use of cultivar mixtures for disease control. In: »Strategies for the Control of Cereal Disease». (Eds. J.F. Jenkyn & R.T. Plumb), pp. 73—80. Oxford, Blackwells. Ms received February 13, 1987 SELOSTUS Lajikeseoslen viljelyarvo kevätvehnän tuotannossa: Laatuominaisuudet Hannu Salovaara Helsingin yliopiston elintarvikekemian Ja -teknologian laitos 00710 Helsinki Reijo Karjalainen Helsingin yliopistonkasvipatologian jakasvinjalostustieteen laitokset, 00710 Helsinki Helsingin yliopiston koetilalla tutkittiin vuosina 1984 ja 1985 kevätvehnän seosviljelyn vaikutusta vehnän laa- tuominaisuuksiin. Tutkimuksen tavoitteena oli selvittää seosviljelyn mahdollisuuksia parantaa hyvälaatuisen lei- pävehnän tuotantoa. Koelajikkeiksi valittiin kasvuajal- taan myöhäiset Tähti, Hankkijan Tapio jaKadett. Täh- ti valittiin korkean valkuaispitoisuutensa jahyvien sako- lukuominaisuuksiensa perusteella, kun taas Hankkijan Tapio ja Kadett edustavat uutta satoisaa mutta laadul- taan hieman heikompaa lajiketta. Koeaineistosta tehtiin tärkeimmät laatumääritykset Helsingin yliopiston elintar- vikekemian ja -teknologian laitoksella. Tulokset osoittavat, että seosten sadontuotanto oli lä- hellä niiden komponenttien keskiarvoa. Kadett oli satoi- sin, kun taas Tähti oli kaikissa kokeissa selvästi heikko- satoisin. Tähden jaKadettin seokset olivat heikkotasoi- sempia kuin Tähden, Tapion ja Kadettin seokset. Seos- ten laatuominaisuudet eivät poikenneet olennaisesti seos- ten komponenttien keskiarvosta. Valkuaispitoisuus ja valkuaisten laatu olivat seoksissa yleensä vähintään lajikkeiden keskiarvojen tasoa, usein hieman näitä parempia. Jauhon Teologiset ominaisuudet olivat samansuuntaiset kuin valkuaisenkin. Tulokset viit- taavatkin siihen, että vehnän laatu ei heikkene seoksessa, mikäli viljaerien sakoluvut ovat hyviä. 55