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Theses

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2004 - 20104
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Subject: Agrometeorology × End date: 2019 × Thesis Type: Ph.D ×
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Now showing 1 - 4 of 4
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    ThesisItemOpen Access
    Influence Of Weather Parameters And Soils On Crop Growth And Productivity Of Wheat
    (Govind Ballabh Pant University of Agriculture and Technology;Pantnagar, 2004) Saxena, Rani; Bhardwaj, Venkatesh
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    ThesisItemOpen Access
    Studies on carbon dioxide concentration in ambient air in relation to meteorological parameters in Pantnagar and surroundings
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2009-08) Mishra, Ashutosh Kumar; Bhardwaj, Venkatesh
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    ThesisItemOpen Access
    Sequential simulation of wheat and urd using DSSAT model in mollisol of Tarai region of Uttarakhand
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2010-01) Neeraj Kumar; Suman Kumar
    For the present study, the experiments were conducted at the Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar to calibrate and validate of DSSAT model for wheat and Urd, to quantify evapotranspiration losses, to select some suitable mathematical methods based on meteorological parameters for estimating ET from wheat and Urd. Model performances were excellent in 2007-08 as compared to 2008-09 because the 2007-08 data were used in the calibration process. During the sequential simulation, the model performance was good enough. Model prediction in the case of yield and yield attributing were high as the DSSAT model accounts the fixed nitrogen by pulse crop to wheat crop. The DSSAT model is a reliable tool for simulating the wheat and urd cropping system. Evapotranspiration from wheat and Urd was also estimated by using mathematical methods of Stephens and Stewart, Jensen and Haise and Blaney and Criddle. For both of wheat and Urd, the yield per hectare was higher during 2007-08 in comparison to 2008-09 due to favourable weather conditions. The average total rainfall during wheat season 2007-08 and 2008-09 were less. Thus, supplementary irrigation was required during crop season due to low rainfall. Jensen and Haise method was found to be most suitable for estimation of ET in Tarai region of Uttarakhand. During vegetative phase of wheat, the temperature and ET were low while during reproductive phase, temperature and ET were high and relative humidity was low in both years. The weather conditions were favorable for good growth and development of wheat. The low temperature, low ET and low relative humidity during vegetative phase are favorable for higher yield of wheat.
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    ThesisItemOpen Access
    Effect of climate change on productivity of wheat and possible mitigation strategies using Ceres-Wheat Model in foot hills of western himalayas
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2010-07) Pal, Raj Kumar; Murty, N.S.
    The present study was conducted at the Norman E. Borlaug Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar to quantify the effect of climate change on productivity of wheat and possible mitigation strategies using CERES-wheat model in foot hills of Western Himalayas during 2007-08 and 2008-09. Model performance was excellent in 2007-08 as compared to 2008-09. The experiment was laid out in split plot design (SPD) with three dates of sowing i.e. Nov. 20, Dec. 15 and January 09 and two varieties viz. PBW-343 and WH-542. Variety PBW-343 was found to yield more besides its attributes than WH-542 with crop sown on 20th November over rest of the sowing dates in both the years. The performance of CERES-wheat (DASST 4.5) model was well with crop sown on 15th December than 20th November and 09th January sowing during the period of study for almost all the crop characters. Predicted values through CERES-wheat model were very close to the observed for the variety PBW-343 than WH-542. All crop characters in terms of days to attain anthesis and physiological maturity, product weight, unit product weight, product harvest index and vegetative weight decreased as the temperature (i.e. Tmax, Tmin and Tmean) increased either by 1, 2 or 30C and vice-versa across sowing dates and varieties. Increasing trends were found for all the crop characters as radiation increased from 1 to 3 MJ/m2/d (except days to attain anthesis and physiological maturity) and vice versa among sowing dates and varieties. The model was found to be more sensitive to solar radiation either increasing or decreasing it than mean temperature. Product weight, product harvest index and vegetative weight increased with all levels of projected CO2 concentration (i.e. 414, 522 and 682ppm in 2020s. 2050s and 2080s, respectively) among the dates of sowing and varieties. Decreased days to attain anthesis and physiological maturity, product weight, product harvest index and vegetative weight were found with all projected temperatures (viz. 1.30C, 2.90C and 5.20C in the years 2020, 2050, and 2080, respectively) alone and also in combination with CO2 concentration at all levels for all the sowing dates and varieties. Weather parameters generated by WGEN were very close to observed weather in both the years. Weather parameters generated by WGEN and ClimGen were used for prediction of crop characters [i.e. product weight, product harvest index and vegetative weight], in which WGEN almost gave good results, so it can be recommended for (crop) modelling applications. With optimized package and practices in climate change scenario during the year 2050, days to attain anthesis and physiological maturity shifted almost by one week and product weight and vegetative weight increased by 403 kg/ha and 1088 kg/ha, respectively, over present package and practices. Advancing sowing period by almost one week i.e. 15th December sowing (mid-sown) resulted in higher yields under modified climate.