Two field experiments were conducted at the Experimental Farm of Sakha Agricultural Research Station during two successive seasons 2010 and 2011. The objectives of this investigation are to study the tolerance of some sunflower genotypes to different soil salinity levels and some soil properties. Four Sunflower genotypes i.e. line 350, line 450, line 800 and Sakha 53 were grown under three levels of soil salinity where: EC values were namely, (S1 2: < 4), (S2 4: < 6) and (S3 6: < 8) dSm-1. Split plots design was used, the main plots were assigned by the salinity levels and the sunflower genotypes were allocated in sub plots with four replicates.
The obtained results can be summarized as follow:
Sodium adsorption ratio (SAR) of soil paste extracts after harvesting greatly increased with increasing salinity. Total nitrogen, available phosphorus and available potassium increased with increasing soil salinity. Soil salinity significantly affected sunflower yield and yield component. Sunflower seed yield (kg /fed.) had the following sequence at the salinity level: Sakha 53 > line 350 > line 880 > line 465 with S1, line 880 > line 350 > line 465 > Shakha 53 with S2 and line 465 > line 350 > Sakha 53 > line 880 with S3.The investigated Sunflower genotypes can be arranged according to oil yield (kg/fed.) as follows:-
Sakha 53 > line 880 > line 465 >line 350 with S1, line 880 >Sakha 53 > line 350 >line 465 with S2 and line 880 >Sakha 53 >line 465 >line 350 with S3. Head diameter/ plant, Weight of seed /plant and 100-seed weight significantly decreased with increasing soil salinity levels.
Sunflower genotypes line 465 and line 880 were the highest tolerant genotypes to soil salinity, whereas the line 350 and Sakha 53 had moderate tolerance to soil salinity.