changes in anatomy, pigment contents, and nutrients of barley cultivars biofertilized by azotobacter chroococcum and pseudomonas fluorescens

Biofertilizers can enhance crop nutrient availability and grain yield. a barley greenhouse experiment was laid out to measure the effect of biofertilizers on flag leaf anatomical structure, pigment contents, grain yield, and nutrient content. treatments included barley cultivars (zehak and nimrooz), and fertilizer treatments consisted of control (no fertilizer applied) (c), seed inoculation by azotobacter chroococcum (azt) and pseudomonas fluorescens (psd) alone, azotobacter with pseudomonas (azt+psd), azotobacter and pseudomonas with 100 kg ha^-1 urea (azt+psd+100u), application of 100 (100u), and 200 kg ha^-1 urea (200u). the flag leaf midrib, metaxylem, and protoxylem areas were the largest in the 200u and azt+psd+100u in zehak, whereas in nimrooz the leaf areas tended to be lower. increasing flag leaf area was related to increasing protoxylem and metaxylem area of the midrib. the stomatal area reached maximum values in zehak, increasing by 47 and 40% in 200u and 100u treatments, respectively. azt+psd+100u affected total chlorophyll, carotenoid content, and relative water content, positively. azt+psd+100u treatment was able to reach similar grain yields to 200u. the highest grain yield was obtained in 200u (108% increase) and azt+psd+100u (102% increase) in zehak. azt had a greater effect on grain n content, while psd had a stronger influence on p content. a significant relationship was observed between grain yield and midrib area, total chlorophyll, relative water content, and grain n and p content. the co-application of azt+psd and a reduced quantity of mineral n fertilizer (100 u) could be a suitable strategy to improve the sustainability of barley production. biofertilizers can enhance crop nutrient availability and grain yield. a barley greenhouse experiment was laid out to measure the effect of biofertilizers on flag leaf anatomical structure, pigment contents, grain yield, and nutrient content. treatments included barley cultivars (zehak and nimrooz), and fertilizer treatments consisted of control (no fertilizer applied) (c), seed inoculation by azotobacter chroococcum (azt) and pseudomonas fluorescens (psd) alone, azotobacter with pseudomonas (azt+psd), azotobacter and pseudomonas with 100 kg ha-1 urea (azt+psd+100u), application of 100 (100u), and 200 kg ha-1 urea (200u). the flag leaf midrib, metaxylem, and protoxylem areas were the largest in the 200u and azt+psd+100u in zehak, whereas in nimrooz the leaf areas tended to be lower. increasing flag leaf area was related to increasing protoxylem and metaxylem area of the midrib. the stomatal area reached maximum values in zehak, increasing by 47 and 40% in 200u and 100u treatments, respectively. azt+psd+100u affected total chlorophyll, carotenoid content, and relative water content, positively. azt+psd+100u treatment was able to reach similar grain yields to 200u. the highest grain yield was obtained in 200u (108% increase) and azt+psd+100u (102% increase) in zehak. azt had a greater effect on grain n content, while psd had a stronger influence on p content. a significant relationship was observed between grain yield and midrib area, total chlorophyll, relative water content, and grain n and p content. the co-application of azt+psd and a reduced quantity of mineral n fertilizer (100 u) could be a suitable strategy to improve the sustainability of barley production.