Bread wheat quality as affected by different cultivars and nitrogen applications in different locations of northeast Buenos Aires

GONZÁLEZ FG

Rosario, Argentina

Conferencia; 1st Latin American Conference. ICC International Conference on Cereals and Cereals Products. Quality and Safety; 2007

International Association of Cereal Science and Technology (ICC), INTA, SAGPyA, Bolsa de Comercio de Rosario (BCR)

Grain protein and quality could be improve by late season N applications but environment and genotype may affect both traits (1,2,3). The impact of two N applications (early at sowing –EA- and late foliar at heading –LA-) on yield and quality of six cultivars at three locations (LC) of the north-east of Buenos Aires was studied. Three high EA were used: 120, 140 and 160 kgN/ha. At heading 120 lt/ha of Foliar SolU were sprayed over each EA (i.e. 120+23, 140+23 and 160+23 kgN/ha). Yield ranged between 4.5 to 7.2 ton/ha, considering all treatments. The effects of EA, LA and LC on yield were more important than the interactions between them. Location modified yield of four cultivars (13- 54% of the total sum of squares –TSS- of the ANOVA), but only two responded to EA > 120KgN/ha and one showed response to LA. Grain protein (GP, %) ranged between 9.1 to 12.6%, considering all treatments. As EA increased GP improved, depending the magnitude of response on cultivar and location. The response of GP to LA was in general positive, but cultivar and/or location and/or EA modified the response (four cultivars showed some interaction between LC and/or EA and/or LA, explaining between 3.5 to 12.6% of  TSS). The chance of increasing GP by 0.5 points adding 20 kgN/ha from (i) 120 to 140 (by EA) or 120+23 kgN/ha (by LA) was 12.5 and 40% , respectively; and from (ii) 140 to 160 (by EA) or 140+23 kgN/ha (by LA) was 41 and 40%, respectively. Except for one cultivar, the relationship between GP and humid gluten (HG, %) was positive (R2 72-29% depending on cultivar, p<0,005). In contrast, the relationship between GP and dough strength (W, 10-4J) was weak and only three cultivars showed association (R2 34-15%, p<0,05). The PCA showed that GP, HG and W could differentiated cultivars and cultivar x location, while GP, HG and DS (dough stability, min) differentiated locations. LA was better than EA for increasing GP content when N was small but, when N increased, both techniques showed similar impact (compared at the same N level).The combination of location, cultivar and N doses should be taken into account to improve wheat quality production in the north-east of Buenos Aires.