The fungus Fusarium oxysporum Schlecht f. sp. radicis-lycopersici Jarvis and Shoemaker (FORL) causes crown and root rot in tomato (Lycopersicon esculentum Mill.), which is a serious problem for field and greenhouse production causing significant losses. The main objective of this study was to test the efficacy of two commercial bacteria strains Pseudomonas sp. ”Proradix” (DSMZ 13134) (Proradix®, Sourcon Padena, Tübingen-Germany) and Bacillus amyloliquefaciens FZB42 (RhizoVital® 42 TB, ABiTEP, Berlin, Germany) in improving mycorrhization, nutrient status and plant growth of tomato affected by FORL. Soil inoculation with P. sp. ”Proradix” and B. amyloliquefaciens FZB42 in single and combined application significantly improved root and shoot biomass production of tomato, and P, Mn and Zn shoot concentrations in pathogen-infested soil. After application of the bacteria strains, roots of tomato were healthier and showed a significantly higher colonization by arbuscular mycorrhizal fungi if the latter was inoculated too. Combined inoculationd with the bacteria strains and arbuscular mycorrhizal fungi increased the observed effects on dry matter and shoot nutrient concentrations. However, clear synergistic effects could not be detected. The results obtained suggest an important role of rhizosphere interactions for the expression of bio-control mechanisms by inoculation with effective Pseudomonas and Bacillus strains in addition to simple antagonistic effects.

An investigation was carried out on the effects of two plant growth-promoting rhizobacteria and Rhizobium on the seedling growth of Paraseriathes falcataria (l.) Nielsen and mycorrhizal development in two soils with contrasting level of pH (5 and 6) in a greenhouse. The results show that inoculation of Paraserianthes seeds with Pseudomonas sp ‘‘Proradix’’ (DSMZ 13134) and Bacillus amyloliquefaciens FZB42 in single or combined application significantly increased root and shoot dry weight, mycorrhizal root colonization, and nutrient concentration (P. Zn and Cu) in the shoots of Paraseriathes seedlings compared to untreated control. Only in the soil with pH 5, an inoculation with P. sp. ”Proradix®“ in addition to Rhizobium inoculation led to a further increase of all measured variables compared to Rhizobium inoculation alone. In all other treatments, inoculation with PGPRs in addition to Rhizobium inoculation did not lead to a significant increase of any of the measured variables. The results demonstrate that plant growth-promoting rhizobacteria have the potential to promote the indigenous arbuscular mycorrhizal fungi establishment and the growth of Paraseriathes seedlings

Glyphosate, a broad spectrum, non-selective herbicide, is the world´s most important and widely used herbicide. The globally increasing adoption of no-till or reduced tillage systems is becoming a driving force for enhanced glyphosate use. In such systems, glyphosate is applied pre-sowing for weed control and glyphosate may remain in root and shoot residues. To evaluate potential risks associated with glyphosate residues, a pot experiment was conducted under controlled greenhouse conditions with two contrasting soils: weakly buffered acidic Arenosol and highly buffered Luvisol. Glyphosate was supplied as glyphosate enriched rye grass straw (1.2 g DM kg-1 soil) prior to sowing sunflower as a non-target plant. Several physiological parameters, such as intracellular shikimate accumulation as a metabolic indicator for glyphosate toxicity, biomass production and micronutrient status were analyzed. Detrimental effects on sunflower plants linked to glyphosate toxicity were observed only in the Arenosol but not in the Luvisol. This is most probably related to the difference in soil properties. The detoxification capacity of the fine-textured Luvisol, with a high clay content, was high enough for an adequate immobilization and inactivation of glyphosate. On the sandy Arenosol, the level of glyphosate supply exceeded the detoxification capacity. In addition to the difference in detoxification capacity, differences in nutrient bio-availability might also have aggravated the observed inhibition of nutrient acquisition. Thus, the findings suggest the importance of weed residues in transferring glyphosate from target to non-target plants, particularly in no-till or reduced tillage systems, with the consequence of detrimental effects on following crop plants.

Agricultural approaches are suggested to increase micronutrients in cereal grain and then to alleviate human malnutrition. A long-term (1999-2007) field experiment was conducted to investigate the effect of three nitrogen (N) fertilization rates (0, 130 and 300 kg N/ha) on micronutrient density in wheat grain and its milling fractions. There were three N rates in this trail: 0, 130 and 300 kg N/ha. At maturity, grains were harvested and fractionated into flour, shorts and bran for micronutrients, N and protein analysis. The results showed that N fertilization increased iron (Fe), zinc (Zn) and copper (Cu) density in wheat grain compared to the control. Increase of N application rate from 130 to 300 kg N/ha, however, didn't further increase the three micronutrient density in grain. Most micronutrients were accumulated in bran while the lowest micronutrient concentrations were found in the flour. High N application increased Zn and Cu densities in three fractions while for Fe, its density in shorts and bran were increased, not in flour. Manganese (Mn) concentration in grain was not influenced by N application. It is concluded that nitrogen plays an important role in micronutrient accumulation in wheat grain. Proper nitrogen fertilizer management has a potential to enhance both micronutrients and grain protein.