اثر نیتروژن بر عملکرد و اجزای عملکرد گیاه دانه روغنی کاملینا (camelina sativa) در تاریخ‌های مختلف کاشت

به‌منظور ارزیابی خصوصیات زراعی کاملینا در شرایط تغذیه با کود نیتروژن در تاریخ‌های مختلف کاشت، پژوهشی به‌صورت طرح کرت‌های خردشده بر پایه بلوک‌های کامل تصادفی با سه تکرار در سال زراعی 98 1397 در مزرعه تحقیقاتی دانشکده کشاورزی، دانشگاه شهید چمران اهواز اجرا شد. در این تحقیق تاریخ کاشت (15 آبان، 15 آذر و 15 دی‌ماه) به‌عنوان عامل اصلی و نیتروژن خالص (0، 23، 46 و 69 کیلوگرم در هکتار) به‌عنوان عامل فرعی در نظر گرفته شد. نتایج نشان داد بیشترین عملکرد دانه (2653.8 کیلوگرم در هکتار) از تاریخ کاشت اول و تیمار 46 کیلوگرم نیتروژن و بیشترین شاخص برداشت (30.9 درصد) از تاریخ کاشت دوم و تیمار 46 کیلوگرم نیتروژن به‌دست آمد. بیشترین عملکرد روغن (737.9 کیلوگرم در هکتار) نیز مربوط به تاریخ کاشت اول و سطح 23 کیلوگرم نیتروژن بود؛ اما بیشترین درصد پروتئین (28.53) از تاریخ کاشت دوم و سطح 69 کیلوگرم نیتروژن به‌دست آمد. همچنین استفاده بهینه از کود نیتروژن منجر به بهبود صفات مورد بررسی ازجمله تعداد شاخه فرعی، خورجینک در بوته، دانه در خورجینک و وزن هزار دانه شد ولی با تاخیر در تاریخ کاشت میانگین این صفات کاهش معنی‌داری یافت. به‌طورکلی نتایج این پژوهش حاکی از واکنش معنی‌دار کاملینا به میزان کود مصرفی و زمان کاشت بود؛ به‌گونه‌ای که میزان کود مصرفی تا سقف 46 کیلوگرم نیتروژن منجر به افزایش معنی‌دار اجزای عملکرد دانه و نهایتاً افزایش عملکرد دانه کاملینا شد. همچنین تاخیر در تاریخ کاشت مطلوب سبب افت عملکرد کاملینا شد که حاکی از لزوم رعایت زمان مطلوب کشت است.

Effect of Nitrogen Application on Camelina‎ (Camelina sativa)‎‏ ‏Oil Seed Yield and Yield Components at Different Planting Dates

IntroductionCamelina [Camelina sativa (L.) Crantz] oilseed is a lowinput crop that grows and yields well in semiarid regions with lowfertility or saline soils in comparison with other crops. Camelina seeds contain 30–40 percent oil. Camelina is an annual plant from the Brassicaceae family that has short and fast growth. Camelina is well adapted to cool temperate and semiarid climates, it is more tolerant of drought and spring freezing than rapeseed (Brassica napus L.). Also, Resistance to some diseases and pests of other members of Brassicaceae plants is another important features of this plant. Researchbased information is lacking to provide basic agronomic recommendations for Camelina. In general, yield and yield components of Camelina seeds depends on nitrogen fertilization, planting time and climatic conditions. Camelina responds differently to fertilizer management and planting date in different climatic and soil conditions. Selection of crop managements such as planting date and fertilization can increase the quantitative and the qualitative yield of this plant.Materials and MethodsIn order to evaluate the effects of nitrogen fertilizer on agronomic characteristics in Camelina under different planting dates, a study was conducted in splitplot based on randomized complete blocks design with three replications at the research field of Agricultural College, the Shahid Chamran University of Ahvaz, located in the southwest of Ahvaz and the western bank of the Karun River with 31°19׳ʹ N; 48° 41׳ʹ an altitude of 22 meters above sea level during 201819 growth season. Experimental factors included planting date in three times (November 6, December 6 and January 5) as the main plots and nitrogen fertilizer at four levels (0, 23, 46 and 69 kg.ha1) as the subplots. The plant material (seed) of this research was Camelina sativa cultivar Soheil which was prepared from the Biston Shafa Knowledge Foundation Company. Half of the nitrogen fertilizer was spread with phosphorus and potassium in the surface of each experimental unit and mixed with soil before planting. The other half of nitrogen fertilizer used in three sections during three stages of plant phenology included True four leaves, beginning of stem elongation and beginning of silicle emergence.Results and DiscussionAnalysis of variance of traits showed a significant difference between nitrogen levels at each level of planting date in terms of all traits studied, including grain yield, biological yield, harvest index, plant height, percentage and oil yield, etc. Generally, based on the results of the analysis of variance, in all three planting dates. The highest grain yield (2653.8 kg.ha1) was obtained from the first planting date and 46 kgN.ha1 treatment and the highest harvest index in second planting date and 46 kg nitrogen treatment was measured. The highest oil yield (737.9 kg.ha1) belonged to the first planting date and the level of 23 kgN.ha1. However, the highest protein percentages (28.53) was obtained in the second planting date and 69 kg nitrogen treatment. Regarding to the other traits, it was observed that the optimal use of nitrogen fertilizer led to the improvement of the studied traits such as the number of subbranches, silicle per plant, seed per silicle and 1000grain weight, but delay in planting date caused the mean of these traits decreased significantly.ConclusionIn general, the results of this study showed a significant response of Camelina to the amount of nitrogen used and planting date, so that in early planting (November 6) was obtained the highest grain yield, yield components, biological yield, oil yield and protein percentage. But in late planting, especially the third planting date, all the studied traits were reduced due to the collision of the plant reproductive stage with the high temperature at the end of Khuzestan growth season and the reduction of the plant growth cycle. Under three planting dates, nitrogen fertilizer application up to 46 kgN.ha1 increased grain yield, oil yield and some yield components. Based on the results of this experiment, in order to obtain maximum grain and oil yield of Camelina, it is important to consider planting date and optimum nitrogen use.