Response of Bread Wheat Cultivars Inoculated with Azotobacter Species under Different Nitrogen Application Rates

A field trial was conducted to investigate the productivity of three bread wheat cultivars, namely Giza-168, Shandawel-1, and Misr-2, under different fertilization treatments, i.e., azotobacter inoculation, 25% nitrogen (N) + azotobacter, 50%N + azotobacter, 75%N + azotobacter, and 100%N of the recommended level (180 kg/ha). The treatments were laid in a split-plot design, and each was replicated three times. The findings showed that wheat cultivars examined in the two seasons exhibited significant variations (p ≤ 0.05) in plant height (PH, cm), number of tillers m−2 (NTM), number of spikelets per spike (NSS), 1000-grain weight (TGW, g), spike length (SL, cm), biological yield (BY, ton ha−1), grain yield (GY, ton ha−1), straw yield (SY, ton ha−1), harvest index (HI, %), protein content (PC, %), days to 50% heading (DTH), and chlorophyll content (CC, SPAD). As a result, Giza-168 had a higher GY (14%), HI (27%), and TGW (10%) than any of the other two cultivars in both growing seasons. Furthermore, Misr-2 exhibited the highest PH (16%), NTM (26%), NSS (28%), SL (10%), BY (30%), SY (46%), and CC (3%). The application of the two treatments of 100%N and N75% + azotobacter exhibited high and statistically similar performance, resulting in an increase in all studied traits by greater than 30–50% compared to the other three treatments. According to the findings of the current investigation, the application of N fertilizer combined with azotobacter increased wheat yield more than either solely azotobacter or N application. We concluded that the application of nitrogen combined with azotobacter reduced the quantity of applied nitrogen by 25%.