Waterlogging affects a high proportion of cultivated land worldwide. Sunflower, soybean and sorghum growth and yield can be affected differently depending on the moment and duration of waterlogging stress. If stress conditions occur during the critical period for yield potential definition (flowering in, sunflower and sorghum and end of pod formation in soybean) they directly reduce grain number, but if the stress occurs during the grain‐filling period, grain weight would be affected. The aim of this study focuses on determining the effects of the moment and duration of waterlogging stress on the yield and its components in sunflower, soybean and sorghum. This information will be useful to understand the effects of waterlogging on yield and to choose a suitable crop or sowing date based on predicted weather conditions for a certain place. To achieve this objective, four experiments were conducted at the Experimental Station of INTA (Reconquista, Santa Fe, Argentina). The effect of the waterlogging in terms of moment (vegetative, critical and grain‐filling periods) and duration (3, 7 and 10 days) on the three crops was evaluated. Sunflower expressed the most negative impact of waterlogging during the vegetative stages (26, 78 and 98% of yield losses with 3, 7 and 10 days, respectively) while soybean suffered major reductions when the stress occurred during the critical period (5%–17% of yield loses). Sorghum did not express any negative responses for the moments and durations tested. This study suggests that the critical period for a waterlogging event differs, according to crops, from the critical period cited for other stresses. Moreover, the magnitude of the damage will mainly depend on the duration of the event. Further studies are needed to elucidate different physiological responses of the species during waterlogging stress.

中文翻译：

---

涝害对向日葵、大豆和高粱产量和籽粒成分影响的关键时期：比较研究


内涝影响了全球很大一部分耕地。根据涝害胁迫的时间和持续时间，向日葵、大豆和高粱的生长和产量可能会受到不同的影响。如果胁迫条件发生在产量潜力定义的关键时期（向日葵和高粱开花以及大豆结荚结束），它们会直接减少籽粒数，但如果胁迫发生在灌浆期，则粒重会受到影响。本研究的目的是确定涝害胁迫的时间和持续时间对向日葵、大豆和高粱产量及其构成的影响。这些信息将有助于了解涝灾对产量的影响，并有助于根据某个地方的预测天气条件选择合适的作物或播种日期。为了实现这一目标，在 INTA 实验站（阿根廷圣达菲收复失地运动）进行了四项实验。评估了涝灾在时间（营养期、临界期和灌浆期）和持续时间（3、7 和 10 天）方面对三种作物的影响。向日葵在生长期遭受涝害的负面影响最大（3、7 和 10 天分别造成 26%、78% 和 98% 的产量损失），而大豆在关键时期发生胁迫时遭受重大减产（5%–17）。产量损失的百分比）。高粱在测试的时刻和持续时间内没有表达任何负面反应。这项研究表明，根据作物的不同，涝灾事件的关键期与其他胁迫的关键期有所不同。此外，损害的严重程度主要取决于事件的持续时间。 需要进一步的研究来阐明该物种在涝灾胁迫下的不同生理反应。