Two field experiments were conducted during in 2019/20 and 2020/21 seasons to study the impact of integration among mineral and nanoparticle nitrogen (N) fertilizer levels on yield traits and chemical characters of some canola genotypes grown under salt stress conditions. Four treatments of N fertilization (190 kg N/ha as recommended dose; 50% of the recommended, 95 kg N/ha+nano nitrogen (5 L/ha); 25 % of the recommended, 47.5 kg N/ha+nano-nitrogen (5 L/ha), and nano-nitrogen (rate of 5 L/ha). canola genotypes (Trabber, Agamax, and Serw4) performance were assessed under three levels of saline irrigation water (control, 2000, and 4000 mg L-1). Results showed that increasing salinity levels up to 4000 mg L-1 led to decreasing in all studied yield parameters compared with those of control (tap water). Trabber genotype excelled significantly in most of the yield characteristics. Integration between nanoscale and mineral nitrogen fertilizer, i.e. 95 kg N/ha+5 nano N L/ha) showed superiority over all applied N treatments, recording the highest values. It could be concluded that since application of 95 kg N/ha+5 nano N L/ha exploiting the nano form of N saves about 50% of applied nitrogen in canola under saline conditions. Accordingly, nanoparticles help the environmental pollution to be reduced.

Stenotrophomonas sp. is a plant-associated rhizospheric bacteria. It has the capability to enhance plant productivity. It acts as a mineral dissolution and growth promoter for plants under salt-stress conditions. The selected isolates revealed the general morphological and biochemical characteristics of Stenotrophomonas sp. All the isolates exhibited the highest growth density after 15 hr. at 30˚C, resistance to different levels of salinity, different pH levels, and different temperature degrees. Also, the isolates revealed their capabilities to solubilize phosphorus and potassium and to pro-duce different phytohormones. The isolate X.M9 exhibited the highest growth performance in the form of 1.376,1.326,1.292,1.053 and 1.059 OD in most salts’ concentrations compared to all tested isolates respectively. As well it (X.M9) exhibited the highest resistance to low temperatures 10 and 15oC being 0.917 and 1.354 OD respectively. The isolate X.M9 recorded the highest IAA of 83.73 mg/100ml compared to all the tested isolates. The isolate X.M9 were identified using 16 SRNA sequencing and submitted to the GenBank database under accession number No: OP050187 as Stenotrophomonas rhizophila.