Effects of chemical treatments on infestation of Alternaria spp. and Fusarium spp. in correlation with technological wheat quality

In this study, the time of infestation by fungi from genus Alternaria spp. and Fusarium spp. was investigated in different stages of wheat maturity (milk, waxy, and technological maturity); the effects of different fungicides on the yield, technological properties, and content of mycotoxin DON were studied also. The results showed that Alternaria spp. attacked spike and kernel in f lowering and end-f lowering stage, as it was already known for Fusarium species. Fungicide treatment increases the yield up to 20%, test weight by 3.7%, and thousand-kernel weight up to 19.1%. High content of mycotoxin DON, above tolerable limits, was detected only in the treatment with fungicide Caramba and in untreated control

Cereal seed mycopopulations in Serbia

Mycopopulation of cereals-durum wheat (cultivars Žitka and Durumko) triticale (cultivars Goranac and NS tritikale), winter barley (cultivars NS 131, ZA 37 and Jagodinac) and oat (cultivars Slavuj and Rajac) had been studied during three years (harvest 2002, 2003 and 2004) from numerous Serbian localities. In all three investigated years and four cereal species the predominant fungal genus were Alternaria and Fusarium. On seeds there were determinated representatives of genus Penicillium, Mucor, Bipolaris Aspergillus, Stemphylium and Epicoccum, too. The established fungi can significantly affect quality of seeds and flour products

Rhizoctonia root rot (Rhizoctoni solani K ü h n) of sugar beet in province Vojvodina

Sugar beet root rot appears regularly each year, but its intensity depends on agro ecological conditions. The predominant causers of root rot in Vojvodina are fungi from Fusarium genus and species Macrophomina phaseolina. Over the last couple of years, more intense occurrence of Rhizoctonia root rot has been observed. Rhizoctonia solani, the causal agent of root rot is present in sugar beet fields. During 2000-2005, on the territory of Vojvodina, the frequency of Rhizoctonia solani in phytopathological isolations from rotted sugar beet roots was between 0,0-18,2%. The intensity of the disease depends on localities, agro ecological conditions and genotypes. Symptoms of Rhizoctonia root rot were registered at some localities in all regions of Vojvodina: Srem, Banat and Bačka. The disease appearance is above all local. It occurs in small patches, on heavy, non-structured soil and on depressed wet parts of plots. Individual diseased plants can be found during July. Brown rot appears on sugar beet roots, with dried tissue on surface, which is present on the tail as well as on the middle part and the head of root. Tissues with described symptoms are deeper regarding the healthy part of root. On vertical root section, the necrotic changes are clearly visible comparing to tissue section without symptoms. The heavily infected tissue forms fissures on roots in most cases. Besides the above-mentioned symptoms on roots, the plant wilting and leaf handle necrosis as well as leaf dying are also observed. When rot spreads to the whole root head, plants quickly die

Evidence of Prunus host specificity of Pseudomonas cerasi based on detached leaves pathogenicity assay

Bacterial leaf spot, caused by the plant pathogenic bacterium Pseudomonas cerasi is an economic threat to Prunus production worldwide. This bacterium was described in 2016 for the first time as a pathogen of wild cherry in Serbia. With the aim to determine the host specificity within Prunus plant species young detached leaves were inoculated using a method of needleless syringe. Ten Prunus species were tested: P. avium, P. armeniaca, P. cerasus, P. cerasifera, P. domestica, P. dulcis, P. fruticosa, P. mahaleb, P. spinosa and P. persica. Strain of P. cerasi (RE10 originated from wild cherry leaves, Rimski Sancevi) grown on Nutrient Agar {26°C for 48 h), and suspended in sterile distilled water (SDW) to the final concentration of 107 CFU mL· 1 was used as bacterial inoculum. Control leaves were inoculated with SDW. The inoculated leaves were maintained in plastic boxes at ambient temperature. Symptom development in the form of bacterial spot-necrosis was rated five times, every two days until 10 days after inoculation (DAI). Results were expressed as the measured diameters of the spot-necrosis (rnrn), and average value was analyzed. Host range assays showed that developed symptoms caused by P. cerasi strain RE10 varied among ten tested Prunus species. Two DAI the symptom appeared only on leaves of P. domestica (3.5). Further, 4 DAI, symptoms were recorded on P. avium {4.9L P. cerasus {4.9L P. fruticosa {4.66L P. cerasifera {3.88L P. spinosa (3.88) and P. persica {4.88L and on P. domestica necrosis enlarged (4.55). Leaves of P. mahaleb, P. armeniaca and P. dulcis were symptomless. Six DAI spots enlarged and reached 3.66; 4.44; 4.55; 4.77; 4.77; 5.10; 5.22 and 5.54 mm for P. dulcis, P. cerasifera, P. spinosa, P. fruticosa, P. domestica, P. avium, P. cerasus, and P. persica, respectively. P. armeniaca and P. mahaleb were symptomless. Eight DAI the presence of necrotic spots was noted on P. mahaleb (2.77) leaves. At the final rating, 10 DAI, no differences were found in formed spot-necrosis on P. mahaleb {2.77L P. dulcis {4.33L P. cerasifera {4.66L P. fruticosa {5.10L P. avium {5.33L P. spinosa (5.55) and P. cerasus (5.66). Only diameter of spotnecrosis enlarges for P. domestica (5.65) and P. persica (9.11). Leaves of P. armeniaca were symptomless until the end of the experiment. During the whole experiment, no symptoms were found in negative controls. Results obtained in this research provide the significant data of potential risk for further spread of P. cerasi among Prunus species. However, P. armeniaca could be recommended to serve as a source for future breeding programs considering that this Prunus did not result with susceptibility to bacterium P. cerasi

Incidence and distribution of beet necrotic yellow vein virus in Vojvodina

From 1997 to 2004, 67213 ha were surveyed in Vojvodina in order to determine the incidence and distribution of beet necrotic yellow vein virus (BNYVV) the causer of Rhizomania on sugar beet in the fields in Vojvodina. The number of inspected hectares was different and ranged from 4.427 ha in 2004 to 19.254 ha in 2002. The survey showed that BNYVV is not equally widespread in all sugar beet growing areas of Vojvodina. The regions of Srem and Banat had higher incidence of the virus, while in region of Bačka the incidence of virus was lower than in other parts of Vojvodina. The BNYVV was found, on average, on 46,2% in Banat, on 40,6% in Srem and on 32,9% in Bačka of sugar beet acreages involved, during the period of eight years (1997-2004). These results show that BNYVV is widespread in Vojvodina, since the virus was found on 36,7% (24.674 ha) of acreages from 67.213 ha of total sugar beet acreages inspected on incidence of BNYVV in the period from 1997 to 2004

The effect of fungicide treatment on mycotoxin content and yield parameters of wheat

Effects of treatment with triazole fungicide were evaluated on 14 wheat genotypes with respect to mycotoxin (aflatoxins, ochratoxin A and deoxynivalenol), yield, 1000 kernel weight and hectoliter weight. Mycopopulation of seed samples was also determined. According to the results, fungicide treatment can reduce the level of mycotoxins in seed samples in order to improve the quality parameters and reduce the level of fungal contamination

Improved Aflatoxins and Fumonisins Forecasting Models for Maize (PREMA and PREFUM), Using Combined Mechanistic and Bayesian Network Modeling—Serbia as a Case Study

Contamination of maize with aflatoxins and fumonisins is one of the major food safety concerns worldwide. Knowing the contamination in advance can help to reduce food safety risks and related health issues and economic losses. The current study aimed to develop forecasting models for the contamination of maize grown in Serbia with aflatoxins and fumonisins. An integrated modeling approach was used, linking mechanistic modeling with artificial intelligence, in particular Bayesian network (BN) modeling. Two of such combined models, i.e., the prediction model for aflatoxins (PREMA) and for fumonisins (PREFUM) in maize, were developed. Data used for developing PREMA were from 867 maize samples, collected in Serbia during the period from 2012 to 2018, of which 190 were also used for developing PREFUM. Both datasets were split randomly in a model training set and a model validation set. With corresponding geographical and meteorological data, the so-called risk indices for total aflatoxins and total fumonisins were calculated using existing mechanistic models. Subsequently, these risk indices were used as input variables for developing the BN models, together with the longitudes and latitudes of the sites at which the samples were collected and related weather data. PREMA and PREFUM were internally and externally validated, resulting in a prediction accuracy of PREMA of, respectively, 83 and 70%, and of PREFUM of 76% and 80%. The capability of PREMA and PREFUM for predicting aflatoxins and fumonisins contamination using data from the early maize growth stages only was explored as well, and promising results were obtained. The integrated approach combining two different modeling techniques, as developed in the current study, was able to overcome the obstacles of unbalanced data and deficiency of the datasets, which are often seen in historical observational data from the food safety domain. The models provide predictions for mycotoxin contamination at the field level; this information can assist stakeholders of the maize supply chain, including farmers, buyers/collectors, and food safety authorities, to take timely decisions for improved mycotoxin control. The developed models can be further validated by applying them into practice, and they can be extended to other European maize growing areas.</p

Level of seed infection of cultivated sorghum with fungi from genus Fusarium

During the year of 2011, the level of fungi infection with the genus Fusarium was examined in seven genotypes of grain sorghum (Gold F1, A 28, B 28, Alba F1, A 73, B 73, Re 236) grown in six localities: Srbobran, Futog and four localities nearby Bački Petrovac (Bački Petrovac 1, 2, 3 and 4). The rate of seed infection with fungus Fusarium in the investigated period ranged from 0 to 8.5%. The infection did not occur in the genotype B73 (Bački Petrovac 1), while a low rate of infection of 0-3% was detected in the genotype B 28 (Srbobran). Medium rate of infection was recorded for the genotype A 28 (Srbobran) and A 28 (Futog) with 4.25% and for Gold F1 (Bački Petrovac 2) with 5.5%. High rate of infection was recorded for the genotype A 73 (Futog), A 73 (Bački Petrovac 2) (6.25%), Alba F1 (Bački Petrovac 2) (8%) and Re 236 (Futog) (8.5%). One isolate from each F. solani, F. graminearum, F. subglutinans and F. verticilliodes was selected for the pathogenicity investigation. Thirty plants were inoculated from each genotype of grain sorghum (varieties Alba F1 and Gold F1) and broomcorn (var. Reform and Prima). The spraying inoculation with the suspension of mycelium and conidia was performed when sorghum was at the end of blooming on June 19, 2012. The intensity of the infection on the sorghum panicles was reached in the phenophase of milky-wax maturity on July 8, 2012 and the scale of S h a r m a et al., (2010) was used. The symptoms of the artificial inoculation appeared only in the broomcorn. Among all isolates, the isolate of the species F. graminearum manifested the highest pathogenicity on the variety Reform with average score of 4.43 and on variety Prima with 4.17. [Projekat Ministarstva nauke Republike Srbije, br. III 46005: Genetical divergence, technological quality and storage of cereals and pseudocereals from organic production

Gibberella intermedia the pathogen of St. John's Wort, coneflower and marshmallow in Serbia

Gibberella intermedia (Kuhlmann) Samuels et al. (anamorf: Fusarium proliferatum /Matsushima/ Nirenberg) was isolated from seeds of St. John's wort, marshmallow, and coneflower, as well as from roots and stalks of marshmallow and roots of coneflower. These plants had symptoms of leaf chlorosis, malformation, withering and plant dwarfing and were collected from several localities in Serbia during five-year investigations of mycopopulations of the mentioned plants. The morphological characteristics of the pathogen were described