AbstractsBiology & Animal Science

Applied nitrogen effects on yellow mustard (Sinapis alba L.) production in the Willamette Valley

by Alyssa Susan DuVal




Institution: Oregon State University
Department: Crop Science
Degree: MS
Year: 2015
Keywords: seed yield; Mustard  – Fertilizers  – Oregon  – Willamette River Valley
Record ID: 2061387
Full text PDF: http://hdl.handle.net/1957/55814


Abstract

Nitrogen management recommendations for yellow mustard (Sinapis alba L.) production in the high rainfall environment of Oregon's Willamette Valley (WV) are not available. The objectives of this investigation were: (i) to determine the effect of applied nitrogen (N) on seed yield and yield components in yellow mustard, and (ii) to ascertain the effect of applied N on dry matter partitioning and oil production characteristics in yellow mustard. Field trials were conducted over a two-year period at Corvallis, Oregon, USA on 'IdaGold' yellow mustard with five N application rates: 0, 56, 112, 168, and 224 kg N ha⁻¹. Although rainfall differed greatly between the two years, the effect of applied N on seed yield and yield components were similar. Seed yield was increased by 15%-85% with applied N, primarily as a result of N-induced increases in seed weight and number. Yield ranged from 1,080 kg ha⁻¹ with 0 kg N ha⁻¹ to 2,580 kg ha⁻¹ with 224 kg N ha⁻¹. Primary racemes plant⁻¹ was positively associated with increased N; however, secondary racemes plant⁻¹ was not consistently related to N. Siliques plant-1 increased in proportion to N rate and was the result of greater numbers of siliques main stem⁻¹ and siliques primary raceme⁻¹. The relationship of applied N and siliques plant⁻¹ was manifested in seed yield, and as an example, the 224 kg N ha⁻¹ rate yielded 95% and 172% more seeds than 0 kg N ha⁻¹ in 2013 and 2014, respectively. Contributions to yield among main stem and branches varied: the main stem raceme contributed 63-66%, primary branch racemes contributed 33-36%, and secondary branch racemes accounted for the remainder. Seeds on main stems were on average 2.4% heavier than seeds on primary branch racemes within N rates. Nevertheless, N rate differentially affected seed weight as main stem seed weight was increased by 11% with 168 and by 5% with 56 kg N ha⁻¹ in 2013 and 2014, respectively. No effect of N fertilizer on primary branch seed weight was evident in 2013, but 168 and 224 kg N ha⁻¹ increased seed weight in 2014. Stand density, plant height, and above-ground biomass were determined at three developmental stages (stem elongation - BBCH 30, inflorescence emergence - BBCH 50, and harvest - BBCH 87) while leaf area index (LAI) and tissue N content were measured at BBCH 30 and BBCH 50. Applied N affected most dry matter partitioning and oil production characteristics with the exception of stand density, harvest index (HI), and seed protein concentration. Plant height, biomass, LAI, and tissue N concentration at BBCH 30 and 50 as well as crop growth rate (CGR) from BBCH 30 to 87 were related to the rate of applied N. Applied N increased plant height by 24 to 105%. Although lodging occurred in both years at the highest N rates, lodging did not negatively influence plant growth and seed yield development, nor total oil yield. As a measure of stand photosynthetic capacity, LAI was lowest across developmental stages with 0 kg N ha⁻¹ in 2013, and in the 0 and 56 kg N ha⁻¹ treatments in 2014. Increases in CGR by applied…