Barley yield and malt characteristics as affected by nitrogen and final irrigation timing.

Idaho is a major malt barley (Hordeum vulgare L.) producer in the United States. Production is concentrated in the semi‐arid Snake River Plain region of southern Idaho. Irrigation and fertilizer N applications are two of the most important managed factors. Research was conducted at the University of Idaho Kimberly Research & Extension Center near Kimberly, ID, to determine yield, grain quality, and malt characteristics as affected by N application rate (0, 56, 112, and 168 kg N ha−1) and final irrigation timing at Feekes 10.0 (boot; F10.0), Feekes 11.2 (soft dough; F11.2), and +7 d after Feekes 11.2 (+7F11.2). Irrigation termination at F10.0 resulted in decreased yields and unacceptable malt characteristics across N rates. Irrigation termination at F11.2 and +7F11.2 yielded 6,439 kg ha−1 at a fertilizer N application of 56 kg N ha−1, similar to higher N applications. Greater predicted yields up to 6,886 kg ha−1 were calculated by regression analysis with applications up to 147 kg N ha−1. Grain yield, protein, plumps, and test weights did not differ at any N rate for F11.2 or +7F11.2. Malt extract, free amino N, and diastatic power were similar for the F11.2 and +7F11.2 irrigations. Malt β‐glucan content did not differ up to 56 kg N ha−1 for any treatment, but reductions of up to 30 mg kg−1 were measured at higher N rates for the +7F11.2 irrigation. Results warrant further investigations into increased N applications and provide evidence of the effects of irrigation cutoff timing and N for malt barley. Core Ideas: Irrigation termination at the F10.0 stage caused severe yield and quality issues.F11.2 and +7F11.2 yields did not differ and increased with N from 4,769 to 6,845 kg ha‐1.Grain protein was less than 130 g kg‐1at all N rates for F11.2 and +7F11.2.Irrigation past F11.2 did not generally improve or detract from quality.Malt β‐glucan decreased up to 30 mg kg‐1at higher N rates for +7F11.2. [ABSTRACT FROM AUTHOR]