Malting barley quality: Response of different cultivars to late season nitrogen application in the northeast of Buenos Aires

GONZÁLEZ FG

Rosario, Argentina

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

ICC, INTA, SAGPyA, BCR

The potential quality of malting barley production is estimated by the grain size distribution (it should have >85% grains > 2,5mm) and grain protein content (it should be <12% and >9%). The first is a grain uniformity requirement of malting industry, while the second is negatively correlated with malt extract content (%). Nitrogen is crucial to manage both grain size and protein content. In Argentine malting barley is recently expanding to the north-east of Buenos Aires and new information about management in that environment should be generated for a successful introduction. The objective was to evaluate the impact of late season N foliar applications on yield and quality (grain size, protein content and malt extract) of five cultivars of malting barley in the north-east of Buenos Aires. The commercial cultivars Ayelen, Danuta and Scarlet, and two experimental cultivars Exp1 and Exp2 (Cerveceria y Malteria Quilmes SA), were sown on 10th July in the field Los Poronguitos, Rojas, Buenos Aires. The soil had 59 (0-20cm) and 44 (20-40cm) ppm NO3 , and 22 (0-20cm) and 13 (20-40cm) ppm P prior sowing. Urea was applied at sowing increasing N availability of the soil to 112 kgN/ha. When the cultivars reached boot stage, 120l/ha of Foliar SolU were sprayed (ca. 23 kgN/ha). Yield was not modified by the late N application, ranging between 6.5 to 5.5 ton/ha, depending on cultivar. The grain size (% grain > 2,5mm) ranged between cultivars from 82 to 95%. Only Scarlet responded to late N application decreasing from 94.3 to 91.5% (p<0.05) grain size distribution when N was spayed. Grain protein content ranged between 8.9 to 11.2% depending on cultivar and N application. All cultivars increased the protein content when N was sprayed at boot stage, but the response was statistically significant (p<0.05) in Danuta (from 10.4 to 11.2%) , Scarlet (from 8.9 to 9.6%) and Exp1 (from 9.9 to 10.5%). Late season N application would be a useful tool to improve malting barley quality in north-east Buenos Aires when the growing season exceed the planned yield and N availability is not enough to reach the minimum required level of grain protein. To improve production and prediction of malting barley quality in the north-east of Buenos Aires, the use of crop N level indicators should be studied to decide the late season N application.