Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 2.37

GRAIN YIELD, NITROGEN-USE EFFICIENCY AND BAKING QUALITY OF OLD AND MODERN ITALIAN BREAD-WHEAT CULTIVARS GROWN AT DIFFERENT NITROGEN LEVELS

G. GUARDA*, S. PADOVAN*, G. DELOGU**

*) Istituto di Genetica e Sperimentazione Agraria N. Strampelli- Provincia di Vicenza

**) Istituto Sperimentale per la Cerealicoltura Sezione di Fiorenzuola d’Arda (PC)

bread wheat varieties, grain yield, nitrogen use, grain quality

The high yields of today’s modern wheat cultivars imply the use of high input which lead to both higher production costs and a greater risk of environmental pollution. Increasing public awareness of the latter issue, along with growing consumer demand for more healthful products, has led on one hand to greater criticism being levelled at this type of production model and on the other to heightened emphasis on crops grown under integrated-management and organic systems. This applies also to wheat. By contrast, the yield increments registered by the new wheat cultivars over this time have been bolstered by the progressively higher N-inputs. All that has led to the idea that the modern cultivars selected under conditions of high N-input are little suited to low-input conditions with respect to the old wheat populations and cultivars. The present study investigated the responses of grain yield and quality and N-use efficiency at three input rates (N₀, N₈₀ , N₁₆₀ kg ha^-1) in a set of 16 of the most representative bread-wheat cultivars from 1900 to 1994.

The average yield rise throughout the time was 33.5 kg ha^-1 year¹, due to an increase of 124 kernel number m^-2 year^-1 and of 0.22 % year^-1 for harvest index. In the same time grain N-accumulation increase from 0.21 kg ha^-1 year^-1 at N₀ rate to 0.67 and 0.82 kg ha^-1 year^-1 for N₈₀ and N₁₆₀ kg ha^-1, respectively, This increase is matched by average yield increments of 44, 50 and 47 kg per kg of N-accumulated. The cultivars exhibited a progressive rise in demand for N-supply over time of release so as to maximize yields accompanied by the upgraded capacity of N-use and an enhanced quality traits: W and P/L rise from values between 65-170 and 0.25-0.39 per cultivar from 1900 to 1970 to 174-241 and 0.48-0.52 for those released after 1970. All the data show that over the last century the goal of upgrading both yield amounts and grain quality for bread-making was successfully achieved. This success also indirectly led to an improved plant nitrogen uptake and use, clear indicators that even under conditions of limited inputs or under organic-farming practices the best results are to be attained by employing not old populations or varieties but modern cultivars, the latter being the only ones with the intrinsic traits capable of ensuring yield and quality at low N supply even though they maximise their traits at high nitrogen inputs.