Display omitted
•Variations in planting patterns for increased densities are evolving.•A high planting density was effective on yield if the inter-row spacing was narrow.•When the planting density is ...increased, the single plant yield potential is reduced.•The lower single plant yield potaential is balanced by the higher plant population.
Increasing the maize plant population has undergone a constant evolution over the years, with the purpose of enhancing the crop yield. Field trials, in which 2 different experiments were considered, have been conducted in NW Italy in order to analyze the yield benefit of high plant density on recent hybrids, considering both intra-row and inter-row plant spacings. The first experiment, which was carried out during the 2013 and 2014 season, evaluated the effects of 4 growing plant densities (from 7.5 to 12plantsm−2) combined with 2 row widths (the traditional 0.75m and a narrow inter-row spacing of 0.50m) on plant architecture and grain yield. Two hybrids, with different ear developments (fixed and flex), were taken into account. The higher plant density led to a decrease in the stalk area (−20%), leaf greenness (−5.2%) and cob length (−10.8%). It also negatively affected the kernel weight (−7.1%) and the number of kernels per row (−10%). The grain yield only increased significantly, for both hybrids (+7.4%), if a density of 10.5plantsm−2 was reached when the inter-row spacing was reduced (0.50m). In the second study, an innovative system (narrow inter-row spacing combined with a plant population of about 10.5 plantsm−2) was compared with a standard planting system (7.5plantsm−2 sown on 0.75m wide rows), considering 32 different production situations (PS) over 4 growing seasons (2011–2014). This study has confirmed that even though the single plant yield potential was reduced in terms of ear weight and thousand kernels weight by 18% and 6%, respectively for a high planting density, the final grain yield increased on 90% of the PS with an average gain of 11.7%. This work has proved that, in the conditions in which the experiments were conducted, a high planting density of up to 10.5plantsm−2 can lead to a significant yield increase, but only when it is combined with narrow inter-row spacing. These conditions increase plant stresses, and modify plant morphology and development to the detriment of the single plant yield. However, the lower yield per plant is fully compensated by the higher plant population.
Cereals can be contaminated by several mycotoxins, whose co-presence may represent an undervalued risk for humans and animals. Maize and wheat are the most contaminated cereals and in temperate areas ...could be affected in field conditions by several
and
infections. To date, only B-fumonisins (FBs), aflatoxins (AFs), zearalenone (ZEA), deoxynivalenol (DON) and T-2 and HT-2 toxins have been regulated in cereals in European Union. The other fungal metabolites, are commonly referred to as "emerging" and "masked" mycotoxins, and more information on their occurrence in combination with the regulated mycotoxins, are needed to design combined toxicological and exposure assessments. This research intends to develop and compare two multiresidue HPLC-ESI-TQ-MS/MS methods for the simultaneous determination of the main regulated, emerging and masked mycotoxins in maize and wheat, among which: FB
, FB
, DON, ZEA, AFB
, AFB
, AFG
, AFG
, moniliformin (MON), deoxynivalenol-3-glucoside (DON-3-G), 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), nivalenol (NIV), enniatins A, A
, B, B
(ENNA, ENNA
, ENNB, ENNB
). The extraction was performed for both methods using a mixture of CH
CN/H
O/CH
COOH (79/20/1, v/v/v), while the dilution/purification was carried out through two different procedures: (1) by the "dilute-and-shoot" technique diluting 1:2 the filtered extract with CH
CN/H
O/CH
COOH (20/79/1, v/v/v) to reduce the matrix effect; (2) using the Oasis
PRiME HLB clean-up columns. The analysis was carried out using CH
OH and H
O both acidified with 0.1% of CH
COOH as eluents. The injection volume was 20 μL and the flow rate 200 μL min
. The analysis of two reference material (maize and wheat), was performed to evaluate the trueness and precision of the two methods by matrix-matched calibration curves. For all the regulated mycotoxins analyzed by both methods, the range of recovery percentage established by the Regulation (EC) No. 401/2006 was respected, except for ZEA by using the Oasis
PRiME HLB clean-up columns. Nevertheless, the results suggest that the Oasis
PRiME HLB clean-up columns, could be a valid alternative to the dilute-and-shoot method, although an additional cost for the clean-up has to be considered. In conclusion, both two analytical methods considerably reduce the analytical time and costs and therefore result to be promising and applicable for high-throughput routine multi-mycotoxins analysis by the use of a TQ.
The increasing demand for healthy baked goods boosted studies on sourdough microbiota with beneficial metabolic traits, to be used as potential functional starters. Here, 139 yeasts isolated from ...cereal-based fermented foods were in vitro characterized for their phytase and antioxidant activities. The molecular characterization at strain level of the best 39 performing isolates showed that they did not derive from cross contamination by baker's yeast. Afterwards, the 39 isolates were in vivo analyzed for their leavening ability, phytase activity and polyphenols content using five different wholegrain flours, obtained from conventional and pigmented common wheat, emmer and hull-less barley. Combining these findings, through multivariate permutation analysis, we identified the 2 best performing strains, which resulted diverse for each flour. Doughs singly inoculated with the selected strains were further analyzed for their antioxidant capacity, phenolic acids, xanthophylls and anthocyanins content. All the selected yeasts significantly increased the total antioxidant activity, the soluble, free and conjugated, forms of phenolic acids and anthocyanins of fermented doughs. This study revealed the importance of a specific selection of yeast strains for wholegrain flours obtained from different cereals or cultivars, in order to enhance the pro-technological, nutritional and nutraceutical traits of fermented doughs.
In an open field trial on two agricultural soils in NW Italy, the impact of two seed-applied biostimulants on the rhizosphere bacterial community of young maize plants was evaluated. The 16S rDNA ...profiling was carried out on control and treated plant rhizosphere samples collected at the 4-leaf stage and on bulk soil. In both soils, the rhizospheres were significantly enriched in Proteobacteria, Actinobacteria, and Bacteriodetes, while the abundances of Acidobacteria, Cloroflexi and Gemmatimonadetes decreased compared with bulk soil. Among the culturable bacteria genera that showed an increase by both biostimulants, most are known to be beneficial for nutrient uptake, such as
,
,
,
,
,
and the species
; others are known to be involved in root growth, such as
,
,
and
; or in plant defence, such as
,
,
, and
. Both biostimulants were also found to stimulate gen.
, a potential biocompetitive agent against aflatoxigenic
moulds. Under controlled conditions, both biostimulants enhanced the shoot and root biomass at the 4⁻5 leaf stage. We conclude that the biostimulants do not decrease the biodiversity of the microbial community rhizosphere of young maize plants, but stimulate rare bacterial taxa, some involved in plant growth and pathogen resistance, a result that may have implications in improving crop management.
In temperate areas, the main limitation to the use of maize in the food chain is its contamination by B-series fumonisins (FBs) during cultivation. Since the content of this group of mycotoxins may ...be distributed unevenly after milling, the aim of this study was to compare the distribution of FBs in maize fractions derived from two industrial dry-milling processes, that is, a dry-degermination (DD) system and a tempering-degermination (TD) system. Grain cleaning reduces FBs by about 42%. The germ of the two degermination processes showed a similar FB content of kernel after cleaning. Conversely, an animal feed flour resulted in a FB content that was two times higher than whole grain before cleaning. A significant FB reduction was observed in the milling fractions in both processes, with a higher reduction in the TD system than in the DD one. The average decontamination respect to uncleaned kernels in the DD process was 50%, 83% and 87%, for maize flour, break meal and pearl meal, respectively, while it was 78%, 88% and 94% in the TD process for small, medium and flaking grits, respectively. Among the milling fractions, the flaking grits with the highest particle size resulted in the highest FB reduction.
The enhancement of
head blight (FHB) resistance is one of the best options to reduce mycotoxin contamination in wheat. This study has aimed to verify that the genotypes with high tolerance to ...deoxynivalenol could guarantee an overall minimization of the sanitary risk, by evaluating the contamination of regulated, modified and emerging mycotoxins on durum wheat
with different degrees of FHB susceptibility, grown under different meteorological conditions, in 8 growing seasons in North-West Italy. The years which were characterized by frequent and heavy rainfall in spring were also those with the highest contamination of deoxynivalenol, zearalenone, moniliformin, and enniatins. The most FHB resistant genotypes resulted in the lowest contamination of all the mycotoxins but showed the highest deoxynivalenol-3-glucoside/deoxynivalenol ratio and moniliformin/deoxynivalenol ratio. An inverse relationship between the amount of deoxynivalenol and the deoxynivalenol-3-glucoside/deoxynivalenol ratio was recorded for all the
and all the years. Conversely, the enniatins/deoxynivalenol ratio had a less intense relationship with
tolerance to FHB. In conclusion, even though the more tolerant
, showed higher relative relationships between modified/emerging mycotoxins and native/target mycotoxins than the susceptible ones, they showed lower absolute levels of contamination of both emerging and modified mycotoxins.
Maize cropping systems need to be re-designed, within a sustainable intensification context, by focusing on the application of high-use efficiency crop practices, such as those that are able to ...enhance an early plant vigor in the first critical growth stages; such practices could lead to significant agronomic and yield benefits. The aim of this study has been to evaluate the effects of the cultivation of hybrids with superior early vigor, of the distribution of starter fertilizers at sowing, and of the seed application of biostimulants on promoting plant growth and grain yield in full factorial experiments carried out in both a growth chamber and in open fields. The greatest benefits, in terms of plant growth enhancement (plant height, biomass, leaf area) and cold stress mitigation, were detected for the starter fertilization, followed by the use of an early vigor hybrid and a biostimulant seed treatment. The starter fertilization and the early vigor hybrid led to earlier flowering dates, that is, of 2.1 and 2.8 days, respectively, and significantly reduced grain moisture at harvest. Moreover, the early vigor hybrid, the starter NP fertilization, and the biostimulant treatment increased grain yield by 8.5%, 6.0%, and 5.1%, respectively, compared to the standard hybrid and the untreated controls. The combination of all the considered factors resulted in the maximum benefits, compared to the control cropping system, with an increase in the plant growth of 124%, a reduction of the sowing-flowering period of 5 days, and a gain in grain yield of 14%. When choosing the most suitable crop practice, the diversity of each cropping system should be considered, according to the pedo-climatic conditions, the agronomic background, the yield potential, and the supply chain requirements.
Among the fungal diseases that affect wheat in temperate growing areas, Septoria Leaf Blotch (SLB) and Fusarium head blight (FHB) result in yield and sanitary risk losses that could be minimized ...through appropriate fungicide applications. Furthermore, the request from policy makers and the food market to reduce the use of chemical pesticides in agriculture has driven research in the direction of performant defense strategies with a reduced spraying of pesticides. The aim of this study was to evaluate the effects of different fungicide programs on the control of SLB and FHB, as well as on the grain yield and deoxynivalenol (DON) contamination of common wheat. Field experiments were carried out in 2016 and 2017 in North Italy. Two seed treatments (conventional vs. systemic) and four combinations of foliar fungicide applications (untreated control, application at the end of stem elongation, at flowering, and a double treatment at stem elongation and flowering) have been compared, according to a full factorial design, under two agronomic conditions: plowing vs. minimum tillage. Foliar sprayings at the end of stem elongation were found to be more effective in controlling SLB, while a triazole application at flowering was found to be an essential practice to reduce the FHB and DON contents. The double foliar treatment led to significant benefits, albeit only in the production situations with the highest SLB severity (e.g., in the 2017 experiment, after ploughing and the use of a conventional seed treatment). The systemic seed dressing led to a higher and prolonged STB protection, with significant canopy greenness during ripening in all the production situations. In 2017, which suffered from high disease pressure, the seed treatment with systemic fungicide led to a significant increase in grain yield (+5%), compared to the conventional one. The combination of the systemic seed treatment and the triazole application at flowering guaranteed the highest control of both SLB and FHB, maximized grain yield, and minimized DON contamination. This study provides useful information that could be used to evaluate appropriate fungicide programs, based on a combination of seed and foliar treatments, for wheat yield and sanity in distinct SLB and FHB diseases pressure scenarios.
The European Food Safety Authority is currently evaluating the risks related to the presence of emerging mycotoxins in food and feeds. The aim of this study was to investigate the role of soil ...fertility, resulting from different nitrogen fertilization rates, on the contamination of regulated mycotoxins and emerging fungal metabolites in maize grains. The trial was carried out in the 2012–2013 growing seasons as part of a long-term (20-year) experimental platform area in North-West Italy, where five different N rates, ranging from 0 to 400 kg N ha−1, were applied to maize each year. Maize samples were analyzed by means of a dilute-and-shoot multi-mycotoxin LC-MS/MS method, and more than 25 of the most abundant mycotoxins and fungal metabolites were detected. Contamination by fumonisins and other fungal metabolites produced by Fusarium spp. of the section Liseola was observed to have increased in soils that showed a poor fertility status. On the other hand, an overload of nitrogen fertilization was generally associated with higher deoxynivalenol and zearalenone contamination in maize kernels, as well as a higher risk of other fungal metabolites produced by Fusarium spp. sections Discolor and Roseum. A balanced application of N fertilizer, in accordance with maize uptake, generally appears to be the best solution to guarantee an overall lower contamination by regulated mycotoxins and emerging fungal metabolites.
The fungal ear rot of maize cultivated in temperate areas is mainly due to the Fusarium species. The use of insecticides against European Corn Borer (ECB) reduces the severity of fungal ear rot as ...well as the fumonisin (FB) and moniliformin (MON) levels in maize kernels at harvest, which in turn results in a lowering of their effect on deoxynivalenol (DON) control. However, the direct fungicidal control of ear rot has rarely been implemented for maize, and the first studies reported conflicting results on the reduction of mycotoxins. In the present experiment, field trials were carried out in North Italy over three growing seasons to study the effect of fungicide application timings on maize to control mycotoxins, considering the interaction of the application with the insecticide treatment, according to a full factorial split plot design. The mycotoxin content was determined through LC−MS/MS analysis. The field trials showed a significant reduction in ECB severity (75%), fungal ear rot severity (68%), Fusarium Liseola section infection (46%), FBs (75%) and MON (79%) as a result of the insecticide application for all the years, while the DON content increased by 60%. On the other hand, a fungicide application alone or applied in plots protected by an insecticide was never effective for the fungal symptoms, infection or mycotoxin content. The results confirm that a correct insecticide application to control ECB damage is the most effective agrochemical solution for the control of fungal ear rot, FBs and MON.
PDF
