الفهرس 
Acknowledgement
Yield components traitsOnly 14 pages are availabe for public view
 |  | from | 119 |  |  |
| | | from | 119 | | |
Abstract
This study was carried out during 2012/ 2013 and 2013/ 2014 seasons in the Agronomy Department Experimental Farm, Agriculture Faculty, Assiut University to study the effect of irrigation levels and nitrogen fertilizer splitting on the productivity of some wheat cultivars. Six experiments each season were done. Three subjected to bread wheat cultivars and the rest subjected to durum wheat cultivars. Each experiment was subjected to one irrigation level (100, 75 and 50 % of irrigation requirement i.e. I1=4000, I2=3000 and I3=2000 m3, respectively). These amounts of irrigation water were recorded from the counter. The experiment was laid out in Randomized Complete Block Design (RCBD) in split - plot arrangement with three replicates. Two treatment of nitrogen fertilizer splitting (2 and 4 times) were arranged in main - plots and the wheat cultivars (Sids 1 and Giza 168 belong to bread wheat) or (Beni-suef 1 and Agaseed 3 belnge to durum wheat) were arranged in sub-plots. Wheat grains were sown by hand on 1 and 2 December in the first and second seasons, respectively. The recommended dose of nitrogen fertilizer (75 kg/fed as a form of Urea, 46.5% N) divided into two equal doses and add before second and third irrigation in the first splitting treatment (2 time), while, splitting into four equal doses (4 times) was added before the second, third, fourth and fifth irrigation. Plant height (cm), spike length (cm) , kernels weight spike, 1000-kernel weight, number of spikes m2, Biological, grain and straw yields traits as well as nitrogen use efficiency were determined which their results can be summarized as follows:
Firstly concerning bread wheat experiments:
A-Vegetative traits:
1- Plant height (cm): presented data show that irrigation levels, nitrogen fertilizer splitting, cultivars and their interaction involved had a significant influence on wheat plant height in the two growing seasons. Data exhibited in this respect reveal that cultivated Sids-1 cultivar subjected to I1 irrigation level and received nitrogen fertilizer at four equal doses gained the highest mean values of plant height(97.20 and 91.17 cm in the first and second seasons, respectively).
2- Spike length (cm): Exhibited data i reveal that irrigation levels, nitrogen fertilizer splitting, cultivars and their interaction involved had a significant influence on wheat spike length in the two growing seasons. Data presented here state that cultivated Sids-1 cultivar subjected to I1 irrigation level and received nitrogen fertilizer at four equal doses gained the highest mean values of spike length (13.50 and 13.10 cm in the first and second seasons, respectively).