Speaker
Description
Introduction
Spring crops and especially grain legumes are expected to be vulnerable to increasing drought due to climate change in Europe (Nendel et al., 2023). The magnitude of climatic changes on yield variability remain unclear, particularly under different exposure periods during plant growth stages. For this purpose, we carried out an experiment to simulate the effect of drought using rainout shelters on five common and novel grain legume species grown under standard cultivation practices in Germany. The research objects were, (i) to investigate the responses of grain legume crops to imposed reductions in precipitation (drought stress) under field condition, by measuring grain yield and yield components, (ii) to assess the effect of timing of this drought stress during flowering and pod-filling.
Methods
The factors in the experiment were, (i) plant species (soybean, chickpea, field pea, yellow lupine and white lupine) and, (ii) water availability (irrigated, rainfed, rainfed with drought stress during flowering stage, and rainfed with drought stress during pod-filling stage). Number of pods per plant, biomass, TKW and grain yield were determined. The 1 m2 harvested plots were in the middle of the shelter area for treatments with rainout shelters.
Results
Reducing the rain during the pod-filling phase of yellow lupin decreased the number of pods by 0.4 pods per plants, the biomass by 46% and the grain yield by 0.52 t ha-1, while irrigating yellow lupine with additional 35 mm increased the number of pods by 1.34 pods per plants, the biomass by 30% and the grain yield by 0.31 t ha-1 compared to the rainfed treatment. In chickpea, the variety Irenka and Castor were both affected by drought during flowering, decreasing the number of pods by 1.34 and 3.7 pods per plant, the biomass by 18% and 37%, and the grain yield by 0.15 and 0.37 t ha-1, respectively. On the other hand, drought during pod filling did not affect chickpea yield structure, and rather increased the grain yield slightly. No significant reduction or increase in the yield and yield structure of white lupin was detected by the different treatments during both stages. There was also no effect observed for field pea that was much earlier in growth and already affected by drought before the rainout shelters were implemented. For soybean, the variety Tofina was not affected by the reduction of rain during flowering, however drought during pod filling decreased the biomass by 15 % and the grain yield by 0.97 t ha-1. On the other hand, irrigating soybean with additional 85 mm in the drought periods, increased the number of pods by 1.35 pods per plant, biomass by 12 % and the yield by 0.35 t ha-1.
We conclude that grain legumes exhibit varying responses to drought at different growth stages. Chickpeas were notably susceptible to drought stress during flowering, while soybean and yellow lupin was affected by drought during pod filling. On the other hand, white lupin showed minimal impact under drought conditions. Further research will investigate the effect of drought on the grain quality characteristics.
References
Nendel, C., Reckling, M., Debaeke, P., Schulz, S., Berg‐Mohnicke, M., Constantin, J., Fronzek, S., Hoffmann, M., Jakšić, S., and Kersebaum, K. C. (2023). Future area expansion outweighs increasing drought risk for soybean in Europe. Global Change Biology 29, 1340-1358.
| Keywords | grain legumes, drought stress, rainout shelter |
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