The effects of sulfur fertility on yield and seed components in oilseed Brassica carinata

• Published in: Crop science 2021-11, Vol.61 (6), p.4229-4238
• Main Authors: Stansly, Theodor L., Seepaul, Ramdeo, George, Sheeja, Small, Ian, Wright, David
• Format: Article
• Language: English
• ISSN: 0011-183X; 1435-0653
• DOI: 10.1002/csc2.20586

The fatty acid profile of oilseed (Brassica carinata A. Braun) has prompted interest as a renewable fuel feedstock due to the high proportions of erucic acid (C22:1) in its seed. In addition, B. carinata produces sulfur (S)‐rich secondary metabolites called glucosinolates (GSLs) that protect the plant from pests and disease but it could also reduce the palatability and nutritional value of animal feed when the seed meal is used as a protein supplement. In B. carinata, it is not clear how S availability could be used to reduce total GSL content (TGC) or its possible effects on yield or oil productivity and quality. In this study, we evaluated the effects of S fertility on seed yield and components important to meal quality like TGC, crude protein content (CPC), and factors affecting oil quality including total oil content (TOC) and erucic acid content (EAC). We compared three B. carinata genotypes with varying seed TGC and one low GSL, B. napus L., grown under a semicontrolled greenhouse environment. A 2‐yr study found that increasing S fertility of deficient plants increased seed yield, TGC, EAC, and CPC without significantly affecting TOC. Seed TGC can be reduced by limiting S but with some potential for yield penalties. Only ‘Avanza 641’ and ‘AAC A120’ produced seed at the 0% S rate, indicating an increased efficiency for S acquisition compared with other genotypes. This study shows that S requirements may be similar between oilseed Brassica regardless of seed GSLs, that limiting S can reduce TGC but to the detriment of seed yield, and a positive relationship between TGC to EAC, providing an opportunity for improving oil quality. Core Ideas Seed yield of B. carinata increases with increasing S availability. Limiting S availability will reduce total GSL content in seeds of B. carinata. TOC remains constant while its quality increases with reduced S availability. There is a direct correlation between TGC in seeds and erucic acid. There is an increase in protein content in seeds with increasing GSL.