Yield losses in wheat and barley in response to different waterlogging durations

DE SAN CELEDONIO RP; BOTTI F; ABELEDO LG; MIRALLES DJ

Beijing

Congreso; 7th International Crop Science Congress; 2016

Abstract: Waterlogging is an important constraint to crop production, which is expected to increase its frequency as a result of climate change. In wheat and barley, the period from stem elongation to anthesis was identified as the more sensitive to waterlogging in terms of yield losses. The objective of this work was to evaluate yield losses of wheat and barley exposed to different waterlogging durations during the sensitive period. A pot experiment (12L) was carried out in which one cultivar of wheat and one of barley were exposed to different waterlogging durations: 0, 5, 10, 15, 20, 25 and 30 days previous to anthesis. Relative yield losses (i.e. percentage of the control for each species) as a function of waterlogging duration showed a bi-linear response (R2=0.99 for each curve). Non-reductions on yield were found from 0 to 5 days of waterlogging and a linear negative response was evident from 5 days onwards. For barley, yield reduced 1.6% per day of waterlogging, which represented a final 68% of yield loss with 30 days of waterlogging. For wheat, yield reduced 1.3% per day of waterlogging until 20 days (reaching at this point 28% of yield loss), but wheat yield fell sharply after 25 days of waterlogging (86% of yield loss). In both species, yield losses were associated primarily with reductions in grain number per plant (R2=0.99), and in less magnitude with grain weight (R2=0.82 in wheat and 0.81 in barley), as well as decreases in biomass production (1.47% per day, R2=0.95 for both species) were more pronounced than decreases in harvest index (0.99% per day in barley, R2=0.80 and correlation in wheat). In conclusion, durations of 5 days of waterlogging or lower did not produce yield reduction in any species, but longer exposition to waterlogging reduced yield linearly in wheat as well in barley. Analysis of ecophysiological variables is a promising tool for designing strategies to mitigate the impact of waterlogging in grain crops.