The effects of short-term waterlogging on the lint yield and yield components of cotton with respect to boll position

•Biomass and lint yield of FB9–16 was increased by waterlogging.•The highest biomass and lint yield for FB9–16was measured under 6 days’ waterlogging.•Insufficient assimilates were preferred compensation in boll number to boll biomass.•Position 3 or higher bolls was important in relieving yield loss after waterlogging.•Higher photosynthesis, better reproductive growth promoted fiber biomass accumulation.

The objectives of this study were to determine the influence of waterlogging on the lint yield and yield components, biomass accumulation and distribution in the cotton boll with respect to boll position. Cottons were subjected to waterlogging 66 days after the seedlings were transplanted into ponds created by maintaining 1–2 cm of water on the soil surface for 0, 3, 6, 9 or 12 d. The ponds were then drained to allow recovery. The tap root and main stem biomass were significantly reduced and the plant biomass decreased resulting from decreased biomass in fruiting branch 1–8 (FB1–8) after waterlogging. The vegetative and reproductive biomass of FB9–16 increased by altered fruiting dynamics resulted from previous waterlogging, and the highest biomass was measured in 6 days of waterlogging (WL6). Waterlogging of 3, 6, 9 and 12 d resulted in a 16.0%, 24.1%, 39.5% and 50.2% reduction in lint yield, due to decreased boll number. Altered fruiting dynamics after waterlogging increased the contribution of bolls at position 3 on FB9–16 to the total yield due to an increase in boll number. The proportion of the boll wall and the seed biomass increased, while the proportion of the fiber biomass and the fiber/seed ratio decreased progressively with waterlogging duration. Insufficient assimilates were preferred compensation in boll number to boll biomass. These findings demonstrate that the bolls at various positions differed in their response to waterlogging and that even short periods (3 d) of waterlogging can have considerable long-term effects on the growth of cotton.