پاسخ‏ های برخی صفات زراعی و کیفی ژنوتیپ‏ های سیب‏ زمینی به محلول‏ پاشی ترکیبات ضدسرما (فریزبُن و پتاسیم) در دو تاریخ کاشت مختلف

به منظور مطالعه واکنش‌های صفات مورفولوژیکی و فیزیولوژیکی ارقام سیب‌زمینی به کاربرد مواد ضدسرما در دو تاریخ کاشت مختلف، آزمایشی به صورت طرح اسپیلت‌ ‌فاکتوریل در ‌قالب‌ طرح بلوک‌های‌ کامل ‌تصادفی با سه تکرار‌ در ‌ایستگاه ‌تحقیقات ‌کشاورزی ‌و ‌منابع ‌طبیعی‌ اردبیل ‌در دو سال زراعی 98-1397 و 99-1398 اجرا گردید. فاکتورهای مورد بررسی شامل‌ تاریخ ‌کاشت‌ در‌ دو ‌سطح‌ (10 ‌و 20 مرداد‌ ماه‌)، ‌مواد ضدسرما در دو سطح (محلول‌پاشی با ‌آب‌ به‌ عنوان ‌شاهد و محلول‌پاشی با‌ مخلوط ‌اسید‌آمینه فریزبُن ‌+‌ پتاسیم‌‌)‌ و ژنوتیپ‌های سیب‌زمینی در 10 سطح شامل ‌(901375، 901475، 902375، 7-8708، 106-8709، 3-7009، 905675، 26-8707، آگریا و ساوالان) بودند. براساس نتایج بدست آمده، محلول‌پاشی اسیدآمینه فریزبن توام با پتاسیم باعث افزایش ارتفاع بوته، وزن غده در بوته، محتوای رنگیزه‌های فتوسنتزی، ویتامین ث، قندهای محلول، درصد نشاسته غده و درصد ماده خشک غده گردید. بالاترین میزان این صفات در تاریخ کاشت 10 مرداد مشاهده شد. ژنوتیپ 901475 دارای بیشترین وزن غده در بوته (811.71 گرم) و رقم آگریا دارای کمترین وزن غده در بوته (497.25 گرم) بودند. حداکثر ارتفاع بوته، محتوای کلروفیل a، b، کل، ویتامین ث، قندهای محلول و ماده خشک غده مربوط به ژنوتیپ 26 8707 بود. ژنوتیپ‌های 3 7009 و 26 8707 بالاترین درصد نشاسته غده را به خود اختصاص دادند. براساس این نتایج به نظر می رسد محلول‌پاشی با مواد ضدسرما و کاشت در تاریخ 10 مرداد ماه می‌تواند برای سودمندی تولید سیب‌زمینی تحت شرایط تنش سرمایی توصیه شود.

the response of some agronomic and qualitative traits of potato genotypes to foliar spraying of anti cold compounds (frisbon and potassium) in two different planting dates

extended abstract   introduction: plants are affected by adverse environmental conditions. one of these environmental factors is cold stress, which is one of the main factors limiting the growth and productivity of agricultural products. one of the effects of cold stress is damage to photosynthetic pigments. so that the cold stress causes the light energy absorbed by the pigments cannot be used in photosynthetic reactions. as a result, this light energy causes photo oxidation reactions and ultimately causes the loss of photosynthetic pigments. to protect plants from freezing in agriculture, it is possible to foliar application of chemical and natural compounds on plants before they are exposed to low temperatures. anti freezing compounds are easily absorbed by the plant and participate in all metabolic processes of the plant. this mechanism allows the plant to reserve some of its energy and thus be resistant to environmental stresses. in addition to anti freezing compounds, the state of nutritional elements in the plant plays an important role in increasing the capacity of plants to deal with environmental stresses such as salt stress, drought, cold, etc. one of these nutritional elements is potassium, which plays a very important role in reducing the effects of various abiotic stresses such as drought, salinity, metal toxicity, high and low temperatures, etc. potassium plays key roles in many physiological and biochemical processes such as photosynthesis, protein synthesis, synthesis and transfer of sugars, activation of more than 60 types of enzymes, regulation of osmotic and ionic potassium, and regulation of opening and closing of stomata. potato (solanum tuberosum l.) is an herbaceous plant of the solanaceae family, which is the fourth most important crop in the world in terms of yield and production volume and is used for food, forage, industrial and seed purposes. the appropriate combination of variety and planting date in crops is one of the most important effective factors in adjusting the harmful effects of climate change on the yield of crops. materials and methods: this research was conducted as a split factorial design in the form of a randomized complete block design with three replications at the ardabil agricultural and natural resources research station during the two crop season of 2018 2019 and 2019 2020. the investigated factors include planting date in two levels (august 1 and 11), antifreeze compound in two levels (foliar application with water as a control and foliar application with a mixture of frezzebon amino acid + potassium) and potato genotypes in 10 levels including (901375, 901475, 902375, 8708 7, 8709 106, 7009 3, 905675, 8707 26 genotypes and agria and savalan cultivars). furthermore, before the spraying treatment, samples were taken from the experimental treatments and frozen using liquid nitrogen and stored in a freezer.after 24 hours of freezing, the samples were again collected from the experimental treatments and rapidly frozen using liquid nitrogen before being transferred to the laboratory for measurement of the desired characteristics.after collecting the samples, laboratory experiments were conducted at the faculty of agriculture of ardabil university of medical sciences and the agricultural and natural resources research station in ardabil. results and discussion: according to the results, it was determined that foliar application of frezzebon amino acid combined with potassium increased plant height, tuber weight per plant, content of photosynthetic pigments, vitamin c, soluble sugars, tuber starch percentage and tuber dry matter percentage. the highest amounts of these traits were observed on the planting date of august 1. means comparison showed that 901475 genotype had the highest tuber weight per plant (811.71 g) and the agria cultivar had the lowest tuber weight per plant (497.25 g). the maximum plant height, chlorophyll a, b and total chlorophyll content, vitamin c, soluble sugars, and tuber dry matter was related to 8707 26 genotype. on the other hand, 3 7009 and 26 8707 genotype had the highest percentage of starch. based on these results, it seems that the planting date of august 1 and the foliar application of freezbon with potassium can enhance the cold tolerance threshold, growth, and performance of potato cultivars in regions exposed to cold stress by regulating physiological and biochemical responses. conclusion: the combined use of anti freezing compounds of frezzebon and potassium improved the morphological and physiological traits of potato genotypes compared to their non use. results showed that the simultaneous use of anti freezing compounds of frezzebon and potassium increased the mean yield of the plant by 24.08% compared to not using them. on the other hand, the planting date of august 1 had a more favorable effect on the studied traits than august 11. so that the mean yield of the plant on the planting date of august 1 was 12.31% more compared to august 11. according to the results, it can be concluded that the application of anti freezing compounds and the planting date of august 1 caused changes in the morphological and physiological traits of potato genotypes, which provided more suitable conditions for their growth and increase in yield. therefore, it is possible to recommend the planting date of august 1 and the foliar application of frezzebon with potassium to achieve optimal yield in the potato fields of the ardabil region.