Selection of irrigation regime for seed production of native plant

It is of great significance to establish a suitable irrigation regime for the artificial propagation of native plant Lespedeza potaninii in arid areas. Taking the wild excellent herbage L. potaninii from desert steppe of Ningxia as test material, we set up an experiment with nine irrigation regimes (three irrigation times of 2, 3, and 4 times, crossed with three irrigation quotas of 150, 250, and 350 m3·hm-2) to select the best regime by investigating the effects of different irrigation regimes on the agronomic characteristics related to seed production, seed yield and quality, as well as water use efficiency. We found that the irrigation time and quota had significant effect on plant height, branch number, reproductive branch number, inflorescence number, pod number, pod seed number, and the thousand-seed weight. The highest seed yield was obtained in the T3 treatment (irrigating 2 times, 350 m3·hm-2 for each time), which was 49.4% higher than that of the T8 treatment (irrigating 4 times, 250 m3·hm-2 for each time). The T4 treatment (irrigating 3 times, each time 150 m3·hm-2) had the highest water use efficiency. The germination rate and the germination potential of seeds under the T3 treatment were the highest, reaching 88.0% and 84.7%, respectively. The T3 treatment was the suitable irrigation regime for the artificial propagation of L. potaninii seeds based on a comprehensive evaluation using the entropy weight-TOPSIS method.