بررسی اثر تنش خشکی بر عملکرد و برخی خصوصیات فیزیولوژیک ارزن دم‌روباهی (.setaria italica l) در تاریخ های مختلف کاشت

با عنایت به محدودیت در فراهمی آب، تامین حد مطلوب و بهینه مصرف آب جهت دستیابی به عملکرد بالا و اقتصادی در زراعت ارزن حائز اهمیت است. این پژوهش برای ارزیابی اثر تنش خشکی بر عملکرد و برخی خصوصیات فیزیولوژیک ارزن دم‌روباهی در تاریخ های مختلف کاشت انجام شد. آزمایش مزرعه ای به‌صورت کرت‌های خردشده در قالب طرح بلوک‌های کامل تصادفی با سه تکرار در سال های 1391 و 1395 اجرا شد. تاریخ های کاشت (1، 15 و 30 اسفند و 15 فروردین) در کرت های اصلی و تنش خشکی (50، 65 و 80 درصد ظرفیت زراعی) در کرت های فرعی قرار گرفتند. در طول فصل زراعی صفات ارتفاع بوته، تعداد پنجه، طول پانیکول، عملکرد دانه، عملکرد علوفه‌تر و خشک، تعداد روز تا گل دهی، وزن هزار دانه، غلظت پرولین و محتوای کلروفیل تعیین شد. نتایج نشان داد که صفات اندازه گیری شده تحت تاثیر تاریخ کاشت قرار گرفت. کاشت گیاه در 15 اسفند بیشترین عملکرد دانه و صفات دیگر را تولید کرد. بیشترین کاهش عملکرد دانه مربوط به تاریخ کاشت 15 فروردین بود. عملکرد دانه و صفات فیزیولوژیک ارزن در اثر کمبود آب کاهش نشان داد. بیشترین عملکرد دانه در 50 درصد ظرفیت زراعی تولید شد. کمترین عملکرد دانه در 80 درصد زراعی به دست آمد، ولی غلظت پرولین در این تیمار بیشترین مقدار بود. عملکرد دانه در تیمار 50 درصد ظرفیت زراعی نسبت به تیمار 80 درصد، 74 درصد افزایش داشت. درمجموع عملکرد دانه و خصوصیات فیزیولوژیک ارزن به‌طور قابل‌توجهی از شرایط تنش خشکی تاثیر پذیرفت؛ بنابراین جهت دستیابی به بیشینه عملکرد دانه و علوفه، کاشت رقم باستان باید در تاریخ 15 اسفند و مدیریت آبیاری آن بر مبنای 50 درصد ظرفیت زراعی صورت گیرد.

Effect of drought stress on yield and some physiological characteristics of foxtial millet (Setaria italica L.) in different planting dates

Introduction Due to limited water resources in warm and dry areas, achieving maximum yield involves a lot of water consumption, Therefore, one of the important goals in the production of crops In such areas, the minimum water is determined to produce maximum yield In such areas determine at least water is that to produce Maximum performance (Paknejad et al., 2009). Based on climatic data Simulated in Iran For the next 30 years, drought is expected (Khazanedari et al., 2009). Plants are disposable to stress in nature, Drought stress is one of the most important limiting factors such as growth and production of plants have led to a reduction of more than 50% Average production of more crops across the world (Lata et al., 2011). Determine the appropriate planting date for plants is very important and it is an important factor which Affected plant physiological and morphological characteristics (Khodabande, 2009). So the purpose of this research is the effects of planting date and drought stress on grain and forage yield and some of the agronomic traits on foxtail millet. Materials and methods This research was carried out in crop year 2013 and 2017 in Zahak Agricultural Research Station. The experiment was conducted as split plot in randomized complete block design with three replications. The experiment factors included, S150% moisture evacuation (as control), S2 irrigation after 65% moisture evacuation and S3Irrigation after 80% moisture evacuation and planting dates in four levels D123 February, D2 5 March, D3 20 March and 4 April Was considered as a subplot. Each experimental plot was planted in 6 lines 50 cm distance between lines and 5 meters long. Density was used of 10 kg / ha. The test plotting humidity was measured by the TDR regularly. The number of tiller per plant, leaf number per plant, plant height, number of days to reach, panicle length, 1000 grain weight, grain yield and fresh and dry forage yield were recorded. The statistical software MSTATC was used for statistical calculation. The Duncan test was used at 5 percent probability level to distinguish the averages. Results and discussion The results of analysis of variance showed that Planting date, drought stress and interaction of planting date in drought stress had significant differences on number of tillers per plant, leaf number per plant, plant height, number of days to reach, panicle length, 1000 grain weight, chlorophyll and proline concentration grain yield, fresh and dry forages. The highest plant height (83.16 cm), tiller number (2.11), leaf length (22.72 cm), Panicle length (14.08 cm), 1000 kernel weight (3.27 gr), grain yield (1521 kg/ha), fresh and dry fodder yield whit average (25225 and 6608 kg / ha) respectively, concentration of chlorophyll (5.83 mg/g) on sowing date March 15th and the highest concentration of proline (70.85 mg / g) was obtained on April 15. In 50% moisture discharge were the highest plant height (87 cm), number of tillers (2.37), leaf length (24.45 cm), Pancicol length (14.93 cm), 1000 kernel weight (3.25 g), grain yield (1677. In interaction March 15 and 50% moisture evacuation were the highest height (100/16 cm), number of tillers (3.16), leaf length (29.83 cm), panicle length (18.08 cm), 1000grain weight (3.46 gr), fresh and dry forage yield (35550 and 9111 kg/ ha). Conclusion According to the results, it can be stated that drought stress causing reduced production of grain and forage. But given the water shortage crisis in the country and the region, a slight reduction in yield on a scale with less water consumption should be put on the agenda of farmers. Planting of millet on sowing date on March 15 and 50% moisture discharge was caused the plant to be placed in the appropriate temperature conditions which can produce maximum yield. Finally, planting of the plant on March 15 and 50% moisture evacuation are recommended for maximum grain and forage millet yield.