Document Type : Research Paper - Biotic and Abiotic Stress

Authors

• Amir Mohammad Abedi ¹
• Seyed Ali Mohammad Modarres-Sanavy ²
• Ali Heidarzadeh ³

¹ Graduated M.Sc, Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran

² Professor, Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran

³ Graduated Ph.D, Department of Agronomy, Faculty of Agronomy, Tarbiat Modares University, Tehran, Iran

Abstract

Introduction
The agricultural sector plays a critical role in ensuring food security through while conserving natural resources. Oilseed crops require substantial water inputs, making it necessary to identify alternative crops with lower water and nutrient demands. Camelina sativa has emerged as a promising oilseed crop due to its adaptability to unfavorable environmental conditions. Promoting camelina cultivation could help diversify agricultural production and reduce dependence on traditional oilseed crops.
 Materials and Methods
This study aimed to investigate the yield and yield components of camelina under water deficit stress with the application of zeolite and wood vinegar. The experiment was conducted in 2023 at the Agricultural Faculty Farm of Tarbiat Modares University as a split-plot factorial in a randomized complete block design with three replications. The main factor was irrigation regimes at four levels: optimal irrigation, mild water deficit stress, moderate water deficit stress, and severe water deficit stress, corresponding to 20%, 40%, 60%, and 80% depletion of available water capacity, respectively, followed by irrigation to field capacity. Sub-plots included two levels of zeolite application (0 and 8 tons ha^-1) and four levels of wood vinegar foliar application (0, 5000, 10,000, 15,000 ppm) in a factorial arrangement. The Time-Domain Reflectometry (TDR) device was used to determine the irrigation timing and volume, as well as the amount of deep water infiltration. After performing the plowing operation, zeolite was evenly spread over the soil surface in the experimental area and mixed with the soil for the plots designated to have zeolite according to the experimental design. Additionally, foliar application of wood vinegar was carried out at four different stages of plant growth (10 days before flowering, inflorescence emergence, full flowering, and fruiting) to achieve optimal effectiveness.
 Results and Discussion
The results indicate that zeolite application and wood vinegar foliar spraying significantly improved all measured traits under optimal irrigation conditions. The highest grain yield was obtained in the treatment with zeolite application and no wood vinegar application, which showed no statistically significant difference from the treatment with zeolite application and foliar spraying of wood vinegar at a concentration of 15,000 ppm (1,350 kg.ha^-1). Under severe water deficit conditions, the highest grain yield (951 kg.ha^-1) was recorded in the treatment without zeolite application and foliar spraying of wood vinegar at a concentration of 10,000 ppm. Other irrigation regimes did not show statistically significant differences. The highest harvest index (33.86%) was achieved under optimal irrigation in the treatment with zeolite application and no foliar spraying of wood vinegar. Under severe water deficit, the highest harvest index (30.31%) was recorded in the treatment without zeolite application and foliar spraying of wood vinegar at a concentration of 10,000 ppm. These beneficial effects were more pronounced under moderate and severe water stress. However, under severe drought stress, zeolite application did not yield significant improvements, whereas wood vinegar at 10,000 ppm significantly enhanced grain yield and harvest index. These findings suggest that zeolite and wood vinegar can serve as effective strategies to enhance plant performance, particularly in water-limited environments. 
 Conclusion
For maximizing seed and biological yield, moderate water stress combined with zeolite application is recommended as the most cost-effective treatment. Under severe water stress, foliar application of wood vinegar foliar application at 10,000 ppm is recommended to enhance seed and biological yield.
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Keywords

• Biological yield
• Drought stress
• Harvest index
• Seed yield
• Straw yield