Yield responses of two local ecotypes of pearl millet (Pennisetum glaucum (L.) R. Br.) under water stress.

摘要

Deficit or regulated deficit irrigation is one way of saving water in regions with limited water resources, without negatively affecting crop yields. The effectiveness of this approach can be assessed using coefficients of yield responses to water supply. For the purpose of this study, this parameter was monitored using 1 g of salt/litre of irrigation water, under 3 levels of water supply (40, 70, and 100% ETM) applied to 2 local ecotypes of millet (Djerba, DJ; and Kairouan, KN) available in Tunisia. The results showed that the maximum crop water consumptions (ETM) were 497 mm and 562 mm for ecotypes DJ and KN, respectively. Under the 70% ETM and 40% ETM irrigation regimes, crop water consumption was significantly reduced, by 25 and 58% respectively for ecotype DJ, and by 29 and 57% respectively for ecotype KN. The yield reduction obtained was slightly less than that observed under unrestricted water conditions, and with no significant difference between the 2 ecotypes. As a consequence, a yield response factor (Ky) close to 1 was adjusted. This shows the capability of the two millet ecotypes to cope with water scarcity and confirms the importance of pearl millet in regions with limited water resources..