اثرات سیلیس و روی بر کمیت و کیفیت دانه و روغن کلزا در تاریخ‌های متفاوت کاشت

به‌منظور انجام این تحقیق، آزمایشی به‌صورت اسپلیتفاکتوریل در قالب طرح پایه بلوک‌های کامل تصادفی با سه تکرار در سال 97-1396 در ایستگاه تحقیقاتی زراعی قراخیل (قائم‌شهر) اجرا گردید. تیمارها شامل تاریخ کاشت در دو سطح (معمول و تاخیری) به‌عنوان عامل اصلی، منابع سیلیس (عدم مصرف، سیلیکات‌کلسیم و نانوسیلیس) و منابع روی (عدم مصرف، سولفات‌روی و نانوروی) هر کدام در سه سطح به‌عنوان عوامل فرعی بودند. نتایج نشان دادند که به‌غیر از سیلیس دانه (غیر معنی‌دار) سایر صفات مورد مطالعه با تاخیر در کاشت کاهش یافتند. تعداد خورجین در بوته (10.30 و 12.11 درصد)، عملکرد دانه (11.15 و 12.43 درصد) و سیلیس دانه (9.63 و 11.57 درصد) به‌ترتیب با کاربرد سیلیکات‌کلسیم و نانوسیلیس و تعداد دانه در خورجین (14.85 و 13.01 درصد) و روی دانه (21.47 و 26.57 درصد) به‌ترتیب با کاربرد سولفات‌روی و نانوروی در مقایسه با شاهد افزایش یافتند. تعداد خورجین در بوته، وزن هزار دانه و عملکرد دانه با محلول‌پاشی نانوروی در مقایسه با شاهد افزایش (به‌ترتیب 18.66، 15.64 و 20.50 درصد) داشتند. حداکثر تعداد دانه در خورجین در تاریخ کاشت معمولی با سیلیکات‌کلیسم (49.8 دانه) و حداکثر روغن دانه تحت تیمارهای مرکب نانوسیلیس و سولفات‌روی (47.3 درصد) و نانوسیلیس و نانوروی (47.5 درصد) به‌دست آمد. به‌طور کلی یافته‌ها نشان دادند که بالاترین عملکرد دانه و غلظت سیلیس دانه با کاربرد منابع مختلف سیلیس و همچنین محلول‌پاشی نانو روی به‌دست آمد. حداکثر غلظت روی دانه نیز با کاربرد منابع مختلف روی حاصل شد. بالاترین درصد روغن با کاربرد همزمان نانو سیلیس و منابع مختلف روی ثبت گردید.

Effects of Silica and Zinc on the Quantity and Quality of Grain and Rapeseed Oil in Different Planting Dates

Introduction Rapeseed (Brassica napus L.) has a special rank among oilseeds due to its outstanding agronomic characteristics. Planting date is an important factor that affects grain yield, oil content and fatty acid composition. Delay in rapeseed planting reduces vegetative growth period and produces plants with less biomass, and reduces yield components and grain yield due to the exposure of the reproductive stage to high temperatures. Proper nutrition of the plant is one of the important factors in improving the quantity and quality of the product. Silicon is not considered an essential element for excellent plants. However, silicon has an effect on improving plant growth, biomass, seed yield and quality, photosynthesis and resistance to biotic and abiotic stresses. Zinc also regulates plant growth and activates many enzymes. This element is necessary for the synthesis of chlorophyll and the formation of carbohydrates.Materials and Methods In order to conduct this research, a field experiment was conducted as a splitfactorial in a randomized complete block design with three replications at Qhaemshahr Agricultural Research Station (Qarakheil) during 201718. Planting dates as the main plot at two levels (normal planting [7 October] and delayed planting [22 October]), silicon fertilizer sources at three levels (control [no consumption], calcium silicate, nanoSi) and zinc fertilizer sources at three levels (control [no consumption], zinc sulfate, nanoZn) were considered as subplots. Calcium silicate and zinc sulfate (200 kg ha1) were added to the soil before rapeseed planting. Silica and zinc nanoparticles (50 mg l1) were sprayed in two stages of flowering and pod formation. The soil of the test site had clay loamy texture with pH 7.5, organic matter 3.2%, total nitrogen 0.16%, absorbable P 15.7 mg kg1 and absorbable K 101 mg kg1. The average annual rainfall at the test site was 745 mm. Data were analyzed by MstatC statistical software and the means were compared with LSD test at a probability level of 5%.Results and Discussion Plant height, number of pods per plant, number of seeds per pod, 1000seed weight, grain yield, seed oil, grain silica and grain zinc were the studied traits that other than grain silica (nonsignificant) other traits decreased with delay in planting. The present study showed that for each day of delay in planting, 39.15 kg ha1 of grain yield was reduced. With the delay of planting from 7 October to 22 October, the total grain yield decreased by 22.03% due to the decrease in the number of pods per plant, 1000seed weight and number of seeds per pod. Seed oil also decreased by 3.3% with a delay in planting. Number of pods per plant (10.30 and 12.11%), grain yield (11.15 and 12.43%), and grain silica (9.63 and 11.57%) increased with the use of calcium silicate and nanosilica, respectively, compared to the control. The number of seeds in pods (14.85 and 13.01%) and grain zinc (21.47 and 26.57%) also increased with the use of zinc sulfate and nanozinc, respectively, compared to the control. Nanozinc increased the number of pods per plant, 1000seed weight and grain yield compared to the control (18.66, 15.64 and 20.50%, respectively). The maximum number of seeds per pod was obtained in normal planting date with calcium silicate (49.8 seeds) and the maximum seed oil was obtained under the combined treatments of nanosilica and zinc sulfate (47.3%) and nanosilica and nanozinc (47.5%).Conclusion In general, the results of the current study showed that the highest grain yield and grain silica concentration were obtained by application different sources of silica as well as nanozinc foliar application. The maximum concentration of grain zinc was obtained by application different sources of zinc. The highest percentage of oil was recorded with the simultaneous application of nanosilica and different sources of zinc.