Diversity and aggressiveness of the Diaporthe species complex on sunflower in Serbia.

This study aimed to investigate the Diaporthe species associated with Phomopsis stem canker of sunflower (Helianthus annuus L.) in Serbia. The significant increase in sunflower and soybean (Glycine max (L.) Merr.) cultivation may have created the bridge favorable conditions for the distribution of Diaporthe species in this region. The present study identified five Diaporthe species on sunflower: D. gulyae, D. helianthi, D. pseudolongicolla, D. stewartii, and the newly identified D. riccionae based on morphological, molecular, and pathogenic characteristics. The research emphasizes the importance of effective inoculation methods and evaluates the aggressiveness of isolates. Sunflower plants were inoculated using the stem wound method, while seeds of sunflower and soybean were inoculated using the standard seed method. Most of the tested isolates demonstrated high aggressiveness, resulting in over 80% premature wilting of sunflower plants. Additionally, this research examined the aggressiveness of Diaporthe species on sunflower seeds, highlighting D. stewartii and D. pseudolongicolla as common pathogens of both sunflower and soybean. The most aggressive species on seeds was D. stewartii, causing seed decay of up to 100% in sunflower and 97% in soybean. The findings suggest the development of resilient sunflower genotypes through breeding programs and the implementation of strategies to manage cross-contamination risks between sunflower and soybean crops. Furthermore, this study provides insights into the interactions between Diaporthe species and the seeds of sunflower and soybean. Future research will enhance our understanding of the impact of Diaporthe species on sunflower and soybean.

Genetic Diversity and Pathogenicity of the Fusarium Species Complex on Soybean in Serbia.

Using morphological and cultural characteristics for identification, 36 Fusarium isolates were recovered from diseased roots, stems, and seeds of soybean from several localities throughout Vojvodina Province, Serbia. Based on molecular characterization, 12 Fusarium species were identified: F. acuminatum, F. avenaceum, F. commune, F. equiseti, F. graminearum, F. incarnatum, F. oxysporum, F. proliferatum, F. solani, F. sporotrichioides, F. subglutinans, and F. tricinctum. The elongation factor 1-α-based phylogeny grouped the isolates into 12 well-supported clades, but polymorphisms among sequences in some clades suggested the use of the species complex concept: (i) F. incarnatum-equiseti species complex (FIESC)-F. incarnatum and F. equiseti; (ii) F. oxysporum species complex (FOSC)-F. oxysporum; (iii) F. solani species complex (FSSC)-F. solani; and (iv) F. acuminatum/F. avenaceum/F. tricinctum species complex (FAATSC)-F. acuminatum, F. avenaceum, and F. tricinctum. Pathogenicity tests showed that the most aggressive species causing soybean seed rot were F. sporotrichioides, F. graminearum, FIESC, and F. avenaceum. Furthermore, F. subglutinans, FSSC, and F. proliferatum showed a high percentage of pathogenicity on soybean seeds (80 to 100%), whereas variability in pathogenicity occurred within isolates of F. tricinctum. FOSC, F. commune, and F. acuminatum had the lowest pathogenicity. To our knowledge, this is the first study of the characterization of Fusarium species on soybean in Serbia. This study provides valuable information about the composition of Fusarium species and pathogenicity that will be used in further research on soybean resistance to Fusarium-based diseases.

Common millet and soybean intercropping with bio-fertilizer as sustainable practice for managing grain yield and quality.

Climate changes are one of the biggest threats to food security. Sustainable agriculture, focused on eco-friendly practices for highly efficient food production, enables greater resilience and safety. This study experimented on intercropping and bio-fertilizer application as convenient ecological solutions for crop yield stability and quality. The experiment was conducted during 2018 and 2020 with soybean and common millet sown in three sowing patterns: alternating rows, alternating strips 1 (2 rows of soybean + 2 rows of millet), and alternating strips 2 (2 rows of soybean + 4 rows of millet), as well as sole crops (control), with or without a bio-fertilizer Coveron. Grain yield and nutrient grain yield response were calculated through land equivalent ratio (LER) and element-LER (E-LER), while quality was estimated based on the concentration of antioxidants (phytate phosphorus, total phenolic compounds, and yellow pigment) and elements in grains, including potential bio-availability of essential elements. Results revealed LER values to be >1 for all sowing patterns, with the highest one achieved in alternating strips 1 (1.38) together with a greater level of all antioxidants in millet grain. Intercropping significantly enhanced Fe and Mn accumulation in both crops and simultaneously decreased the concentration of potentially toxic elements (Al, Cr) in millet grain. Potential bio-availability of essential elements, expressed through the ratio between phytic acid and Ca, Mg, Fe, and Zn revealed smaller values in intercropped soybean and millet with the bio-fertilizer. The bio-fertilizer also increased the concentration of some micro-elements in millet grain, classifying it as a highly dependent plant to microbial inoculation. Interaction of intercropping and bio-fertilizer was most pronounced for LER, E-LER, and accumulation of Fe and Mn in grains. These results highlighted the benefits of soybean-common millet intercropping, especially in combination with the bio-fertilizer, in light of enhanced land utilization and nutrient absorption, thus increasing the resilience of soybean and millet under dry land conditions and low-input systems toward stability and food security.

Kernel color and fertilization as factors of enhanced maize quality.

Maize is an important staple crop and a significant source of various nutrients. We aimed to determine the macronutrients, antioxidants, and essential elements in maize genotypes (white, yellow, and red kernel) using three different fertilizers, which could be used as a basis to increase the nutrient density of maize. The fertilizer treatments used bio- and organic fertilizers as a sustainable approach, urea, as a commonly used mineral fertilizer, and the control (no fertilization). We evaluated the yield, concentration of macronutrient (protein, oil, and starch), nonenzymatic antioxidants (phenolics, yellow pigment, total glutathione (GSH), and phytic phosphorus), and reduction capacity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, as well as essential elements that are commonly deficient in the diet (Mg, Ca, Fe, Mn, Zn, Cu, and S) and their relationships with phytic acid. The genotype expressed the strongest effect on the variability of grain yield and the analyzed grain constituents. The red-kernel hybrid showed the greatest accumulation of protein, oil, phenolics, and essential elements (Ca, Fe, Cu, and S) than a yellow and white hybrid, especially in the biofertilizer treatment. The yellow kernel had the highest concentrations of yellow pigment, GSH, phytic phosphorous, Mg, Mn, and Zn (19.61 µg g-1, 1,134 nmol g-1, 2.63 mg g-1, 1,963 µg g-1, 11.7 µg g-1, and 33.9 µg g-1, respectively). The white kernel had a greater starch concentration (2.5% higher than that in the red hybrid) and the potential bioavailability of essential metals, particularly under no fertilization. This supports the significance of white maize as a staple food in many traditional diets across the world. Urea was important for the enhancement of the antioxidant status (with 88.0% reduction capacity for the DPPH radical) and increased potential Zn bioavailability in the maize kernels (13.3% higher than that in the biofertilizer treatment). This study underlines the differences in the yield potential and chemical composition of red, yellow, and white-kernel maize and their importance as a necessary part of a sustainable human diet. This information can help determine the most appropriate genotype based on the antioxidants and/or essential elements targeted for kernel improvement.

The conversion of forestland into agricultural land without appropriate measures to conserve SOM leads to the degradation of physical and rheological soil properties.

This study was conducted to compare soil particle density (ρs), soil total porosity (TP), liquid limit (LL), plastic limit (PL), and plasticity index, and their relations with soil organic matter (SOM), of non-carbonate silty clay Fluvisols under different land uses. Three neighboring land uses were studied: native deciduous forest, arable land, and meadow, managed in the same way for more than 100 years. Soil was collected from 27 soil profiles and from three depths (0-15, 15-30 and 30-45 cm). Land use caused statistically significant but different impacts on soil properties, particularly in the topsoil. The forest topsoil measured the lowest ρs and bulk density (ρb) but the highest SOM and soil water content at PL, compared to meadow and arable soil. Statistically significant linear relationship was observed with the SOM content and ρs (- 0.851**), ρb (- 0.567**), calculated TP (0.567**) and measured TP (- 0.280**). There was a nonlinear relationship between SOM and LL (0.704**) and PL (0.845**) at the topsoil. The findings suggested that SOM content strongly affected ρs, ρb, TP, LL and LP. This regional study showed that the conversion of forestland into agricultural land without appropriate measures to conserve SOM leads to the degradation of physical and rheological soil properties.