PRELIMINARI
Marco Napoli*1, Marco Mancini2, Giada Brandani1, Martina Petralli1, Leonardo Verdi1, Simone Orlandini1,
Anna Dalla Marta1
1 Dipartimento di Scienze delle Produzioni Agroalimentari e dell’Ambiente, Università di Firenze, Piazzale delle Cascine 18, 50144, Firenze 2 Fondazione per il Clima e la Sostenibilità, Via Caproni 8, 50144, Firenze
*marco.napoli@unifi.it
Abstract
This research aims to assess the effect of climate and of the agronomic management, in particular sowing density and fertilization, on the growth and development of three ancient genotypes of winter wheat (Verna, Sieve and Andriolo) compared to the modern cultivar Bologna. Results showed that the ancient genotypes reached the flowering stage between 5 and 10 days after the modern cultivar, and required additional GDD_0 between 80 and 184. Nitrogen affected the vegetative as well as reproductive growth of all the four cultivars, resulting in more days and GDD_0 to flowering as nitrogen increased. Concerning the accumulated biomass, Verna showed a positive relation with the three nitrogen levels; Andriolo was not affected by the highest nitrogen rate, on the contrary of Bologna and Sieve. The obtained results allowed to obtain quantitative information about the vegeto-productive responses of the ancient wheat varieties so far unavailable and useful for their cultivation with modern agronomic management.
Keywords: growing degree days; sowing density; fertilization; phenology; dry biomass.
Parole chiave: sommatorie termiche; densità di semina; concimazione; fenologia; biomassa secca. Introduction
Tuscany has a great tradition of durum and ordinary wheat cultivation but in recent years, economic constraints and negative impacts of climate change are increasingly putting at risk such agricultural productions that is not more ensuring a sufficient and stable income for the farmer. This also involves a progressive abandonment of marginal areas that are very expensive to cultivate, both because of low obtainable yields and for technical difficulties of cultivation. In this context, the reintroduction of ancient varieties of wheat adapted to the environment and the development of new cereal supply chains represent therefore a valuable opportunity for farmers. Recent studies demonstrated that some ancient varieties, such as Verna, Gentil Rosso, Frassineto, and Andriolo, have high nutraceutical value due to the presence of polyphenolic compounds in grains. Beside the cultivar itself, also the environment and the crop management strongly affect wheat productivity and the phytochemical profile of the grain (Heimler, 2010). In particular, the quantity and the quality of the final production are affected by the pedo- climatic conditions of the cultivation area and by the agronomic technique, with particular reference to the last phases of the productive cycle, related to the grain filling and ripening. Therefore, the evaluation of the productive potential of these ancient varieties cannot ignore the study of genotype-environment interactions and the identification of an agronomic technique capable of enhancing its yield and its quality. The aim of this research is to assess the effect of climate and of the agronomic technique, in particular sowing density and fertilization, on biomass accumulation and phenological dynamics of three ancient varieties of winter wheat: Verna, Sieve and Andriolo.
Materials and Methods
The field experiments were established in October 2016 under rainfed conditions at the “Giuseppe Chiarion” farm, which is located in Monteroni d’Arbia, about 20 km south-east of Siena, Tuscany, Italy (43.2007 N, 11.4182 E, 160 m asl). Egyptian clover (Trifolium alexandrinum L.) was the previous crop. The soil is a silty clay loam, and the 0–30-cm layer contains 11.4 g kg-1 total organic carbon, 1620 mg kg-1 total nitrogen (N), 14.2 mg kg-1 available phospourus (P), and 273 mg kg-1 potassium (K). A meteorological station was placed near experimental field and data on temperature and humidity are recorded. Four Italian varieties of common wheat (Triticum aestivum L.) are involved in the present study, including three “old” genotypes (Andriolo, Sieve and Verna), and one dwarf registered cultivar (Bologna). The experiment includes 24 treatments, which are the combinations of four varieties of common wheat, three N fertilization levels, i.e. 35, 85 and 135 kg N ha-1 (N1, N2 and N3), and two seeding rates, i.e. 90 and 180 kg ha-1 of seed (D1 and D2). The experimental arrangement is a split-strip-plot
ones (subplots) and seeding density is applied vertically to sub-subplots. Seeds were sown on December 19. No noticeable crop damage was observed during the growing season due to weeds, insects, or diseases.
The phenological development for each variety was recorded (BBCH scale – Biologische Bundesanstalt, Bundessortenamt and CHemical Industry) and elaborated on the basis of the growing degree days with a cutoff of 0 °C (GDD_0). At the flowering three samples of 0.25 m2 were randomly chosen from each sub-subplot to measure plant height (PH; cm), plant
and spike weight per square meter (PDW and SDW; kg m-2).
Statistical comparisons of measured parameters were made with ANOVA. Thereafter, pairwise comparisons were performed using the post hoc Tukey's HSD (honest significant difference) test.
Results and Discussion
During the initial phenological stages (BBCH 9–30) no differences were detected among genotypes, that developed almost simultaneously during the tillering period. The cultivar Bologna and Andriolo were shown to be the earliest and the latest, respectively, in reaching booting (BBCH 40) and middle of the heading (BBCH 55) phases. As regards the flowering stage (BBCH 69) (Table 1) and the extent of the flowering period differences were observed among genotypes. In particular, Andriolo, Verna and Sieve showed a longer growing season than Bologna of 10, 7 and 5 d, respectively, and corresponding to about 184, 122 and 80 additional GGD_0, respectively. Moreover, all the old varieties showed an extended spike flowering period (7.7 ± 1.5 d, 8.3 ± 0.6 d and 9.3 ± 0.7 d for Verna, Andriolo and Sieve, respectively), while Bologna in 5.7 ± 0.6 d passed to the maturity stages (BBCH 71). This trend may be related to an increase of maturity rate of Bologna, due to warm and dry environmental conditions during the last part of the crop cycle which had favoured the typical earliness of the modern cultivar. Nitrogen affected the vegetative as well as reproductive growth, which resulted in more days and GDD_0 to flowering as nitrogen increased. Nitrogen treatments increased the sum of GGD_0 to reach the flowering stage by about 34 GDD_0 for Bologna and Sieve, 56 GDD_0 for Andriolo and 73 GDD_0 for Verna.
Bologna Andriolo Sieve Verna N1 N2 N3 N1 N2 N3 N1 N2 N3 N1 N2 N3 GDD_0 1245 1261 1279 1421 1440 1477 1330 1330 1365 1347 1383 1421 DOY 129 131 132 140 141 143 135 135 137 136 138 140
Tab. 1: Annual dates of the flowering (expressed in days of the year, DOY) and growing degree-days with a cut-off of 0 °C (GDD_0) required to reach the full flowering for the four cultivars of common wheat and the three nitrogen levels (N1: 35
kg N ha-1, N2: 85 kg N ha-1 and N3: 185 kg N ha-1).
Tab. 1: Data di fioritura (espressa in giorno dell’anno, DOY) e gradi giorno cumulate con una soglia di 0 °C (GDD_0) necessario per raggiungere la piena fioritura per le quattro cultivar di frumento tenero e per i tre livelli di azoto adottati
(N1: 35 kg N ha-1, N2: 85 kg N ha-1 and N3: 185 kg N ha-1).
Significant (p < 0.05) positive relationship were determined between sowing density and both PDW and SDW for Bologna (Table 2). On the contrary, PDW and SDW significantly reduced (p < 0.05) with the increasing plant density for the three tall varieties. PH significantly increased (p < 0.05) with the increasing plant density for the old varieties, while PH was not affected for Bologna. Nitrogen effect on PH was not significant on Andriolo and Bologna, while significantly (p < 0.05) affected Sieve and Verna. Verna showed a positive and significant relationship between N levels and both PDW and SDW. PDW and SDW in Andriolo significantly increased with the increasing N content from N1 to N2, but not furter increases were observed for N3 level. On the contrary, PDW and SDW in Bologna and Sieve were not significantly affected by the increasing N content from N1 to N2, while they significanlty increased for N3 level.
Cultivar Nitrogen level Sowing density level PDW (g m-2) SDW (g m-2) PH (cm) Bologna N1 D1 627.56 ab 529.76 b 60.4 f D2 765 ab 586.56 ab 62.13 ef N2 D1 807.12 ab 659.68 ab 61.27 f D2 701.36 ab 519.2 b 60.13 f N3 D1 703.8 ab 586.24 ab 64.33 e D2 1148.88 a 1009.92 a 64.4 e Andriolo N1 D1 973.56 ab 548.96 b 113.07 ab D2 753.8 ab 468.48 b 102.8 abc N2 D1 1204.32 a 633.92 ab 115.13 a D2 1162.24 a 658.4 ab 112.6 ab
N3 D1 1200.96 a 702.72 ab 117.47 a D2 1178.56 a 617.76 ab 110.2 ab Sieve N1 D1 900.72 ab 678.08 ab 93.53 abcde D2 648.12 ab 488.64 b 77.6 cd N2 D1 839.88 ab 641.6 ab 85.2 bcde D2 840.4 ab 563.36 b 86.53 bcde N3 D1 802.84 ab 638.4 ab 90.07 bcde D2 1210.24 a 840.48 a 106.4 ab Verna N1 D1 536.52 ab 397.44 b 85.8 bcde D2 394.44 b 304.48 b 66.33 de N2 D1 661.88 ab 439.2 b 88.93 bcde D2 719.12 ab 468.16 b 98.13 abc N3 D1 1189.24 a 798.4 a 113.13 a D2 947.48 ab 584.16 ab 105.27 ab
Tab. 2: Plant height (PH; cm), plant and spike weight per square meter (PDW and SDW; kg m-2) measured at flowering. in
four wheat cultivars, ‘Bologna’, ‘Andriolo’, ‘Sieve’ and ‘Verna’ grown under two sowing densities (D1: 90 kg ha-1 of seed
and D2: 180 kg ha-1 of seed) and three level of nitrogen (N1: 35 kg N ha-1, N2: 85 kg N ha-1 and N3: 185 kg N ha-1).
Lowercase letters indicate different means (p < 0.05) according to the Tukey post hoc test.
Tab. 2: Altezza della pianta (PH; cm), peso della pianta e delle spighe per metro quadro (PDW and SDW; kg m-2) misurati
alla fioritura per quattro cultivar di frumento tenero, ‘Bologna’, ‘Andriolo’, ‘Sieve’ and ‘Verna’ cresciute in due diverse
densità di semina (D1: 90 kg ha-1 di seme e D2: 180 kg ha-1 di seme) e tre livelli di fertilizzazione azotata (N1: 35 kg N ha-1,
N2: 85 kg N ha-1 e N3: 185 kg N ha-1). Le lettere minuscole indicano differenze significative (p < 0.05) secondo il Tukey post
hoc test.
Conclusion
The research shows that among the ancient varieties, Andriolo and Verna, behave significantly different from the cultivar Bologna, while Sieve is more similar to the modern varieties. In particular, the vegetative phase of ancient wheat is about 8 days longer than modern one, which can result in an interruption of the grain filling due to the limiting environmental conditions, especially high temperature and drought typical of Mediterranean summer period.
Also for the sowing density the response of modern and ancient varieties is opposite, as the latter show a higher efficiency in biomass accumulation also with lower sowing rates. Finally, concerning nitrogen fertilization, the response of ancient varieties is very variable and not clearly explained, therefore more information is expected at harvest.
Acknowledgments
Attività in parte svolte nell’ambito del progetto misura 16.2 “GRANT", PSR 2014/2020 Regione Toscana. Si ringraziano il Consorzio Agrario di Siena, le Az. Agr. Chiarion Giuseppe e Francesco e Podere Belvedere Di Del Sere Federica, e la Fondazione Cassa di Risparmio di Firenze per il supporto fornito.
References
R. Bonhomme, 2000. Bases and limits to using ‘degree day’ units. Eur. J. Agron. 13: 1-10.
A. Dalla Marta, D. Grifoni, M. Mancini, G. Zipoli, S. Orlandini, 2011. The influence of climate on durum wheat quality in Tuscany, Central Italy. International Journal of Biometeorology, 55, 87-96.
F. Guasconi, A. Dalla Marta, D. Grifoni, M. Mancini, F. Orlando, S. Orlandini, 2011. Influence of climate on durum wheat production and use remote sensing and weather data to predict quality and quantity of harvest. Italian Journal of Agrometeorology – 3/2011, 21-28.
G.S. Mc Master, T.R. Green, R.H .Erskine, D. Edmunds, J.C. Ascough II, 2012. Spatial interrelationships between wheat phenology, thermal time and terrain attributes. Agron. J. 104 (4), 1110-1121.
J. R. Porter, M. Gawith, 1999. Temperatures and the growth and development of wheat: a review. Eur. J. Agron. 10: 23- 36.