Evaluation and prediction of some wheat cultivars productivity in relation to different sowing dates under North Sinai region conditions

Two open-field experiments were conducted during 2011=2012 and 2012=2013 seasons at the experimental farm, Faculty of Environ. Agric. Sciences, EL-Arish, Suez Canal University (31° 080 04.300 N, 33° 490 37.200 E). This work was aimed to evaluate the performance of four bread wheat (Triticum aestivum L.) cultivars i.e.; Misr-1, Sakha-93, Giza-168 and Gemmeiza-9 sown at three sowing dates (15th October, 15th November, 15th December) under the metrological conditions of North Sinai. Results obtained from experimental field studies were used as indicators to test the performance of DSSAT-CSM (Cropping System Model) Ver. 4.5.1.023. Necessary files were prepared as required. Calibration and validation of applying CERES-Wheat model was done through using d-Stat index of agreement between simulated and observed values. Field experiment results indicated that under North Sinai environmental conditions, the significantly highest values of spike length, one thousand kernel weight and radiation use efficiency % were recorded by Gemmeiza-9 cultivar under early sowing date (October, 15). However, the highest values of spike weight, grain yield and dry biological yield were obtained when the same cultivar cultivated under mediate sowing date (mid-November). The output data from the CERES-Wheat model showed that Gemmeiza-9 cultivar recorded the highest observed grain yield in the 1st and 2nd seasons (5352 and 5928 kg ha^-1, respectively) and highest predicted grain yield (3957 and 4619 kg ha^-1, respectively) in mediate sowing date (mid-November) as compared to other wheat cultivars Misr-1, Sakha-93 and Giza-168. Generally, Gemmeiza-9 under mediate sowing date (November, 15) is recommended treatment to maximized bread wheat grain yield under North Sinai environmental conditions and all similarity regions.