Early Flowering and Rapid Growth Become Advantageous over Non-Lodging Plants in Field Pea Under Early Drought

Field pea genotypes with tall or semi-dwarf height and with regular or semi-leafless type leaves and tendrils differ in their reactions to drought depending on plant growth and development, impacting final seed yield. In the current opinion paper, arguments are presented showing that terminal drought at the post-flowering and maturing stage can be better tolerated by semi-dwarf and semi-leafless plants with a strong vertical standing ability compared to tall and leafy pea genotypes that suffer severe lodging. On the other hand, early drought at the vegetative stage strongly reverses the preference for faster growing and early flowering tall pea plants with regular leaves. It seems that short and semi-leafless plants lose the advantage of their non-lodging ability in early drought conditions. Meanwhile, drought occurring in the middle of the flowering period causes mixed results, whereby either group of pea genotypes can produce higher seed yield depending on local adaptations. This opinion-paper highlights the importance of characterising the impacts of drought stress at various plant developmental stages, separating differential responses of plants to early and terminal drought stress for pea production. The expected timing of drought, which is specific to different regions, must be used in the development of new cultivars with improved seed yield stability.