تأثیر کاربرد کود زیستی و شیمیایی پتاسیم و وزن بنه بر خصوصیات فیزیولوژیک و عملکرد گل زعفران Crocus sativus L. ))

پتاسیم فراوان­ترین کاتیون­ معدنی در بافت­های گیاهی است که نقش اساسی در فرآیندهای فیزیولوژیک به ویژه رشد و متابولیسم گیاه ایفا می­کند. به منظور بررسی اثرات کود زیستی و شیمیایی پتاسیم و وزن بنه بر برخی صفات فیزیولوژیک و عملکردی زعفران, آزمایشی به صورت فاکتوریل در قالب طرح بلوک کامل تصادفی با هشت تیمار و سه تکرار در مزرعه پژوهشی زعفران دانشکدگان ابوریحان دانشگاه تهران در سال زراعی 96-1395 اجرا شد. تیمارهای آزمایش شامل دو مقدار کود شیمیایی سولفات پتاسیم (0 و 200 کیلوگرم در هکتار) به عنوان فاکتور اول, دو مقدار کود زیستی پتابارور-2 (0 و 100 گرم در هکتار) به عنوان فاکتور دوم و دو وزن بنه کوچک (5-3 گرم) و بزرگ (10-8 گرم) به عنوان فاکتور سوم بودند. نتایج نشان داد که کاربرد کود زیستی و شیمیایی پتاسیم اثرات مثبتی بر صفات اندازه گیری شده داشت, به طوری که منجر به افزایش عملکرد گل از طریق اقزایش تعداد گل, وزن تر گل و نیز وزن خشک کلاله گردید. کاربرد کود زیستی به تنهایی منجر به افزایش سه برابری تعداد گل در بنه بزرگ در مقایسه با بنه کوچک و شاهد شد. غلظت کربوهیدرات و پروتئین کل برگ و نیز آنتوسیانین گلبرگ تحت تأثیر کاربرد تلفیقی هر دو کود قرار گرفت و اختلاف معنی­داری با شاهد نشان داد. بطورکلی نتایج این تحقیق نشان داد که کاربرد بنه بزرگ به همراه آغشته نمودن آنها به کود زیستی پتاسیم و کاربرد پیش از کشت کود شیمیایی پتاسیم در افزایش عملکرد گل و بهبود خصوصیات فیزیولوژیک دخیل در رشد زعفران نقش مؤثری دارد.

 Introduction: Potassium is the most abundant inorganic cation in plant tissues that plays a major role in physiological processes, especially in growth and metabolism. Although there is substantial evidence about the effects of potassium fertilizer on increasing the qualitative and quantitative yield of plants, little is known about the effects of applied potassium on saffron and the improvement of the quality and yield of the saffron flower. The purpose of this study was to evaluate the effects of biological and chemical potassium fertilizer and corm weight on some physiological traits and yield of saffron (Crocus sativus L. ). Materials and Methods: An experiment was conducted as factorial based on a randomized complete block design with three replications and eight treatments at the saffron research field of the College of Aburaihan, the University of Tehran during 2015-2016. Experimental treatments included two levels of potassium sulfate fertilizer (0 and 200 kg. ha-1) as the first factor, two levels of Potabarvar-2 biofertilizer (0 and 100 g. ha-1) as the second factor, and two corm weights including small (3-5 g) and big (8-10 g) were the third factors. Potabarvar-2 biological fertilizer used in the research has a set of the most effective potassium-releasing bacteria called Pseudomonas spp. Strain s19-1 and In order to increase the colonization of bacteria around the corm, irrigation was done after planting and then summer irrigation was done on the first of September, the appearance of the first flower was at the beginning of November and the end of flowering was in the middle of December. In this research, functional traits including the number of flowers, flower fresh weight, stigma dry weight, and physiological traits including petal Anthocyanin, leaf soluble protein, and total leaf soluble Carbohydrate were measured. Results and Discussion: the results of this experiment indicated that the application of potassium, especially in the form of biofertilizer, had positive effects on improving flowering and increasing the number of flowers in both groups of saffron corms, especially small corms (3-5 grams). Also, the increase in the fresh weight of flowers was evident in the combined application of biological and chemical fertilizers, especially in large corms (8-10 grams). The application of potassium sulfate in combination with biological fertilizer had the greatest effect on increasing the concentration of total carbon hydrates, total leaf protein, and petal Anthocyanin content. Applied fertilizers led to increasing in flower yield through an enhancement in the number of flowers, fresh weight of flower, and dry weight of stigma. Application of biological fertilizer alone led to an increase of three times the number of flowers in a big corm in comparison with a small corm and normal. There was a significant difference between normal treatment and application of both mixed fertilizers on the concentration of total Carbohydrate and protein of the leaf and Anthocyanin of the petal. Conclusion: In summary, the results of this experiment indicated that the application of big corms by inoculating them with biological fertilizer of potassium, in addition to using smaller amounts of potassium sulfate chemical fertilizer before sowing would be affected the increase of flower yield and improve physiological traits effectively growth. Therefore, the use of biological potassium fertilizer led to a decrease of using of chemical fertilizers and will be promising for sustainable agriculture and reducing the environmental pollution.