اثر ورمی‌کمپوست و زئولیت بر خصوصیات مورفولوژیک، عملکرد و اسیدهای چرب کدو پوست کاغذی (Cucurbita pepo var. Styrica)

Introduction: Cucurbita pepo is a valuable medicinal plant. It is an annual herbaceous plant belonging to the cucurbitaceae family. Seeds contain different biological substances included fixed oil, carbohydrates, proteins, nutrients and vitamins. This plant has high importance due to its oil included unsaturated fatty acids such as linoleic and oleic acids. Exogenous application of eco-friendly inputs in sustainable systems was thought
to be an ecological strategy for producing high-quality medicinal plant products and increasing yield stability. Thus, this research aims to assess the effects of vermicompost and zeolite, as natural inputs, on quantitative and qualitative traits of Cucurbita pepo in sustainable agricultural systems.
Materials and Methods: This experiment was conducted at the Research Farm of the Kurdistan University in 2020. The experiment with a full factorial layout was conducted using a randomized complete block design with three replications. The experimental treatments included three vermicompost rates (0, 5, and 10 ton/ha) and three zeolite rates (0, 4, and 8 ton/ha). Morphological traits, fruit and grain yield, oil percentage and yield, and fatty acids were assessed. Agronomic traits fruit diameter, grain number per fruit, and 1000-grain weight were randomly measured from five plants at full maturity in each plot. The fruit and grain yield were calculated based on a 6 m2 harvested area in the middle rows. To get the fixed oil out of Cucurbita pepo, the Soxhlet extraction method with n-hexane was used. Then fatty acid methyl esters were prepared for analysis by gas chromatography.
Results: The results showed that the vermicompost and zeolite application significantly increased fruit diameter, seed number per fruit, 1000 seed weight, fruit yield and grain yield. The utilization of 10 tons vermicompost ha^-1 enhanced fruit and grain yield by 25.23%, and 9.47% compared to control treatment, respectively. It can be said that, vermicompost is an organic-rich source of macro- and micro-nutrients, and plant growth regulators which may boost plant growth and biomass by facilitating nutrient absorption over the growing season according to plant requirements. Also, zeolite application (8 ton/ha) increased fruit and grain yield by 17.95%, and 9.86% in compared to the control treatment, respectively. The small molecular size of the open-ringed structure can physically protect NH4+ ions against microbial nitrification. So, it seems that increasing nitrogen, phosphorus, and potassium uptake helped pumpkin yield. Vermicompost and zeolite affect the oil percentage and yield, too. The highest rate of vermicompost (10 ton/ha) enhanced oleic and linoleic acids by 26.3 and 28.6 percentage compared to control, respectively. The third rate of zeolite (8 ton/ha) increased oleic and linoleic acids by 16.1%, and 9.1% compared to the control treatment, respectively. While, the highest values of saturated fatty acids included stearic and palmitic acids belonged to the control treatment. It can be said that, organic inputs can affect soil biochemical characteristics and nutrients uptake by plants. It may have influenced the enzymes and genes involved in the biosynthesis of fatty acids.
Conclusion: Overall, it is suggested that farmers incorporate vermicompost and zeolite, as natural inputs, to improve yield and fatty acids quality of cucurbita pepo in sustainable agricultural systems