Effects of water deficit on grain yield and yield components of Narrow-leaved plantain (Plantago lanceolata L.)

Aims: Drought limits plant growth and productivity throughout the world. Narrow-leaved plantain (Plantago lanceolata L.) is widely used to treat some human diseases and reduce antibiotic nutrition. This study aimed to examine the response of four local ecotypes of P. lanceolata to different drought stress levels in a field experiment. Materials Methods: A split-plot design was conducted using a randomized complete block design (RCBD) with three replications at the farm of Research Institute of Forests and Rangelands, Karaj, Iran, 2018. The main factor was drought stress at three levels (D1= normal irrigation, D2= drought stress after the flowering stage with supplemental irrigation at the filling stage, and D3= stop irrigation after flowering. The second factor contained four ecotypes: G1-Arak, G2-Khoramabad, G3-Meshkinshahr1, and G4-Meshkinshar2. Data were collected and statistically analyzed for grain yield and yield components. Findings: Results showed a significant effect of drought stress and ecotype on all traits except root lengths (p 0.05). The ecotype × drought stress interaction effects were significant for spike number per plant, leaf number per plant, leaf width, and plant height (p 0.05). The mean values of grain yield in D1, D2, and D3 were 729.41, 660.81, and 595.95 kg.h-1, respectively. Conclusion: The highest grain yield of 670.92 kg.h-1 was obtained from G1-Arak. This ecotype produced higher grain yields under mild and severe stress than the other ecotypes and was recommended for breeding improved varieties.