پديدآورندگان :
حسيني طهراني سيدعلي استاديار دانشگاه آزاد اسلامي واحد پزشكي تهران , حقدوست پري فارغ التحصيل كارشناس ارشد دانشگاه آزاد اسلامي چالوس , مظلوم پوريا استاديار دانشگاه آزاد اسلامي واحد چالوس , موسوي امير عباس استاديار دانشگاه آزاد اسلامي واحد چالوس
كليدواژه :
برنج , خسارت ورس , عملكرد دانه , مراحل رشد فيزيولوژيكي
چكيده فارسي :
به منظور بررسي تاثير مرحله زماني وقوع ورس بر ميزان خسارت عملكرد دانه و برخي صفات رشدي دو رقم برنج طارم محلي و رقم پرمحصول شيرودي، آزمايشي به صورت اسپليت پلات در قالب طرح بلوكهاي كامل تصادفي در سه تكرار در اراضي زارعين شهرستان آمل در سال زراعي 1394 به اجرا درآمد. فاكتور اصلي رقم در دو سطح (طارم محلي و شيرودي) و مرحله ايجاد ورس مصنوعي در 5 سطح (مرحله ظهور سنبله جوان، غلاف كامل، شيريشدن، خميري شدن و سفت شدن) به همراه تيمار شاهد (بدون ايجاد ورس) انتخاب شدندنتايج آزمايش نشان داد كه اثر مراحل مختلف ايجاد ورس مصنوعي بجز در مورد تعداد خوشچه كل، روي تمام صفات مورد اندازهگيري عملكرد دانه،عملكرد كاه،عملكرد بيولوژيك،ارتفاع بوته،تعداد پنجه،تعداد خوشچه پر،تعداد خوشچه پوك در سطح احتمال آماري 1 درصد معنيدار بوده است. همچنين مشخص شد كه هرچه ورس در مراحل ابتداييتر رشد اتفاق بيفتد خسارت ورس يعني كاهش عملكرد بيشتر است بطوريكه عملكرد تيمار ايجاد ورس در مرحله ظهور سنبله جوان در دو رقم طارم و شيرودي به ترتيب 3/58 و 4/57 درصد كمتر از عملكرد تيمار شاهد يعني تيمار بدون ايجاد ورس بوده است.
چكيده لاتين :
Lodging is a major problem in the production of cereal crops. Addition to decreasing productivity, lodging also decreases the quality of the rice grains in lodged plants. The lower yield and decreased quality also lead directly to poor profits for farmers. It also causes difficulties in harvest operations and consequently results in increased production cost. The loss of grain yield in lodged plants differs with the state of lodging and the time of lodging. In order to estimate of lodging damage at different physiological growth stages of rice plant (oryza sativa) a field experiment was carried out at rice growing farmers in Mazandaran, during 2015. A test material has been evaluated in a split plot experiment in Randomized Complete Block Design with 3 replications. Two cultivars (Tarom and Shiroodi) were involved in main plot and artificial lodging performed at growth stages (panicle initiation, booting, milky, dough and ripening stages) along with control (unlodged plot) has been set in sub- plot on main plot experiment layout. Before conducting the experiment, surface composite soil samples was taken and some properties of soil such as T.N.V., texture, P and K available, %O.C, pH and EC were analyzed. N, P and K fertilizers applied after soil analysis based on technical instructions of Rice Research Institute. Other cultural practices such as water management and crop protection were the same as those of local farmers. Plot size was 12 m2 per treatment and seedlings were transplanted at 25 25cm spacing. Artificial lodging was made by pushing of plant stem into the ground in predicted stages. Grain yield, biological yield, harvest index, plant height, tiller number, panicle length, number of filled and hollow grain per panicle and 1000- grain weight were determined. N content of grain and straw was determined and N uptake was calculated and the data were evaluated basis on statistical. 12 hill bottom-cut plant samples were taken in each plot to determine the dry matter and harvest index at physiological maturity. Grain and straw samples were analyzed for N content. Grain yields (14% moisture content) were measured at harvest from a 5-m2 sample area per plot and converted to ton per hectare. Data were analyzed statistically with SAS analysis of variance technique at 5% probability level and treatments were compared by Duncan ,s method.
Analysis of variance showed that there was significant difference between two main plots (two cultivars). Experimental results showed that creating of artificial lodging in different stages, except in the case of total spikelets , on all traits were significant at the 1% level of statistical probability. It also found that if the lodging occurs in early growth stages such as panicle initiation, the damage of lodging, i.e. loss of grain yield, will be greater so that grain yield of creating of artificial lodging in panicle initiation was lesser than 58.3 and 57.4 comparison to control treatment ( unlodged plot) in Tarom and Shiroodi, respectively.
