Abstract
Sunflower (Helianthus annuus L.), which is widely grown globally for its high-quality edible oil, is reasonably salt and drought tolerant but it is susceptible to waterlogging. In the saline coastal zone of the Ganges delta, sunflower is often exposed to sudden heavy rainfall during early growth but plant tolerance to such events is not known. Hence, we evaluated the effect of short-term soil inundation (referred to as waterlogging) for 0, 24, 48 and 72 h on sunflower at emergence, 2-leaf, and 4-leaf stages in early- and late-sown crops under field conditions (saline, clay-textured soil, and shallow groundwater). Waterlogging for 24 h did not affect sunflower at any stage but waterlogging for 48 and 72 h suppressed emergence and growth at the 2 and 4-leaf stages. Waterlogging for 72 h completely prevented the emergence for early sowing, whereas emergence was less affected for later sowing. Shoot and root dry weight were most affected at the emergence and 2-leaf stage, not at the 4-leaf stage. In conclusion, waterlogging caused by more than 24 h soil inundation at up to the 4-leaf stage severely depressed emergence and growth, indicating the need for effective drainage at sowing of sunflower in the low-lying coastal saline zone of Bangladesh.
Highlights
In many parts of the world, waterlogging risk for agricultural crops has changed because of less predictable rainfall related to climate variability [1,2,3]
All these studies were conducted in non-saline soils, which may underestimate the effects on sunflower in the Ganges saline coastal zone since waterlogging effects in crops are exacerbated by soil salinity [23]
The effect of waterlogging duration on sunflower was investigated at three stages of early sunflower development and with early and late sowing
Summary
In many parts of the world, waterlogging risk for agricultural crops has changed because of less predictable rainfall related to climate variability [1,2,3]. Singh et al [22] reported that the waterlogging effect was more prominent at the 6 to 8 leaf stage (50 days after sowing) than at the flowering stage (80 days after sowing) All these studies were conducted in non-saline soils, which may underestimate the effects on sunflower in the Ganges saline coastal zone since waterlogging effects in crops are exacerbated by soil salinity [23]. Our previous field observations suggest that early stages of sunflower growth on saline clay-textured soil with a shallow water table were sensitive to heavy post-monsoonal rainfall events [16]. This study, aimed to evaluate the impact of short-term waterlogging on the emergence, and shoot and root development of sunflower at early growth stages, and to determine the most sensitive stage for waterlogging damage and the maximum duration of waterlogging that plants could tolerate under field conditions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
