Investigating of water use efficiency, physiological characteristics, oil, and grain yield of Camelina (Camelina sativa L.) in deficit water conditions, using zeolite, and wood vinegar foliar spraying

IntroductionDue to the water crisis, the import of oil and oilseeds and the outflow of foreign currency, the need to cultivate oilseeds with low input consumption is felt. Camelina (Camelina sativa L.) is considered as a superior option as an oilseed crop with high growth capacity under stress conditions, in infertile soils and in temperate climate. This plant, with a short life cycle between 85 and 100 days, is suitable for cultivation in different agricultural and environmental conditions.Camelina seeds are rich in oil and protein. Camelina oil contains essential fatty acids such as omega-3 and omega-6, tocopherols, phytosterols, and phenolic compounds. Its applications include human nutrition, livestock and poultry feed, biodiesel production, and use in the biopolymer industry. Zeolites are three-dimensional aluminosilicate minerals that contain cations necessary to balance the electrostatic charge of the framework’s tetrahedral aluminum and silicon units. They can effectively combat soil pollution, water contamination, and heavy metal pollution. Additionally, zeolites can enhance water use efficiency and prevent food wastage in dryland areas, leading to increased crop yield. Wood vinegar, also known as pyroligneous acid, is a raw liquid with a reddish-brown hue produced through the biochar pyrolysis process. It mainly contains compounds such as acetic acid, butyric acid, catechol, and phenol. Wood vinegar has properties similar to plant growth regulators and is environmentally friendly. It can also enhance crop resistance to biological and abiotic stress factors.Materials and methodsThis design was implemented in the form of factorial split plots in the form of a randomized complete block design in three replications. The investigated factors include irrigation regimes at four levels (optimum irrigation, mild water deficit, moderate water deficit and severe water deficit) as main plots, natural zeolite (clinoptilolite) factorial at two levels (zero and eight tons per hectare) and wood vinegar at four levels (0, 5000, 10000, and 15000 ppm) were as sub-plots.Results and discussionThe results of the experiment indicate that irrigation regimes, the application of zeolite, and wood vinegar foliar spray have a significant impact on the morphological, physiological, and yield-related traits of the Camelina plant. The highest leaf area index was achieved in the treatment combining mild water deficit, zeolite application, and wood vinegar foliar spray with a concentration of 5,000 ppm. Additionally, the treatment involving wood vinegar foliar spray of 15,000 ppm and zeolite under optimal irrigation conditions resulted in the highest oil yield. The maximum water use efficiency based on seed and oil yield was observed in the treatment with severe water deficit, no zeolite application, and wood vinegar foliar spray at a concentration of 10,000 ppm. Furthermore, the photosynthetic rate was also higher in the treatment with optimal irrigation, zeolite application, and wood vinegar foliar spray of 15,000 ppm compared to other treatments. Based on the findings of this study, the use of zeolite and wood vinegar foliar spray at 15,000 ppm is recommended as the best treatment due to increased performance. Additionally, under mild and moderate water deficit conditions, the application of zeolite and wood vinegar foliar spray of 15,000 ppm is advised, while severe water deficit conditions do not warrant the use of zeolite and wood vinegar foliar spray of 10,000 ppm.ConclusionAccording to the results of this research, the use of zeolite and foliar spraying of 15000 ppm of wood vinegar is introduced as the best treatment due to the increase in seed and oil yield. Also, in mild and medium low water conditions, the use of zeolite and foliar spraying of 15000 ppm of wood vinegar is recommended, and in severe water deficit stress conditions, it is recommended not to use zeolite and foliar spraying of 10000 ppm.