Brassinolide effects on maize (Zea mays L.) growth and yield under waterlogged conditions

Our aim was to assess if Brassinolide (BR) could ameliorate stress caused by waterlogging on maize. Two BR levels (with and without), two maize varieties [Ikom White (IKW) and Obatanpa-98 (Oba-98)] and three growth stages [control (WLo), seedling stage (WL1), and tasseling stage (WL2)] were studied under waterlogging lasting 10 days. Maize growth and development were significantly (p ≤ .05) reduced by waterlogging stress under WL1 than WL2. Waterlogging stress at WL1 adversely affected (p ≤ .05) the protein and relative water contents. The nitrogen (N) content among the plant partitions (leaves, stems, and grains) were reduced (p ≤ .05) at both silking and harvest. The beneficial effect of BR was more pronounced in Oba-98 with higher protein contents, dry matter yield, N-uptake and harvest index than IKW. Oba-98 was also better yielding than IKW. Thus, in a waterlogged soil, treatment of maize plants with BR at WL1 could induce some tolerance.