Evaluation of Some Faba Bean Genotypes to Foliar Diseases under Biological, Organic and Mineral Nitrogen Fertilization

A two-year experiment was conducted at the Sakha Agricultural Experiments and Research Station in the Agricultural Research Center (ARC) in the Kafr El-Sheikh governorate, Egypt, during the 2021/2022 and 2022/2023 seasons. The study aimed to evaluate the resistance of some faba bean genotypes to leaf rust and chocolate spot by applying biological, organic, and mineral N fertilization to enhance seed yield, quality, and farmer’s profits. The treatments were the combinations between three fertilization sources (biological, organic, and mineral N fertilization) and eight faba bean genotypes (Giza 40, Giza 716, Sakha 1, Sakha 4, L2039/437/2015, L2141/353/2015, L2103/591/2014, and L2144/379/2015). The treatments were laid out in a split-plot design with three replications. Fertilization sources were randomly assigned to the main plots, and the faba bean genotypes were allocated in sub-plots. Mineral N fertilization offered better protection against rust disease in Giza 40 and L2039/437/2015 compared to biological or organic fertilization, while chocolate spot disease was lower after 90 days of sowing with biological fertilization. Rust disease incidence was lower in L2144/379/2015 treated with biological or organic fertilization at 70 and 90 days after sowing. L2103/591/2014 and L2144/379/2015 responded positively to biological fertilization, indicating their resistance to chocolate spots. Biological fertilization showed potential in enhancing foliar disease resistance in Sakha 4, Sakha 1, and Giza 716, leading to potentially higher yields. Giza 40 and L2039/437/2015, which were susceptible to foliar diseases, showed higher productivity with mineral N fertilization. Sakha 1, Sakha 4, L2039/437/2015, and L2144/379/2015 had higher seed protein and carbohydrate contents with organic fertilization, while L2103/591/2014 and L2141/353/2015 showed the same with biological fertilization. Giza 716 showed greater economic returns with biological fertilization. Giza 40 and L2039/437/2015 demonstrated higher economic returns with mineral N fertilization. L2141/353/2015 had higher economic returns with organic fertilization, while L2103/591/2014 and L2144/379/2015 showed better returns with biological fertilization. Sakha 1, Sakha 4, Giza 716, and L2144/379/2015 treated with biological fertilization demonstrated higher productivity and profit with good quality compared to organic or mineral N fertilizations, suggesting that L2144/379/2015 is a promising genotype in foliar disease breeding programs.