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The concomitant evaluation of physicochemical properties and development of important diseases, such as brown rot in peaches postharvest, is hampered by the use of destructive methods for physicochemical analysis. Therefore, this study aimed to evaluate the physicochemical characteristics in wounded and unwounded 'Chimarrita' and 'Maciel' peaches inoculated with M. fructicola assessed by non-destructive methods. The fruits were stored at room temperature (25 ºC) for 10 days after harvest. Colorimeter, near-infrared spectroscopy and portable spectrophotometer DA-meter® (single index of absorbance difference, IAD index) were used to evaluate the physicochemical changes that naturally occurred in peaches during postharvest and due to pathogen development on the same fruit simultaneously. Incidence and severity of brown rot were evaluated by counting the number of lesions resulting from inoculation at 24, 48 and 60 h post inoculation. Also, the sporulation of M. fructicola on fruit surface was evaluated. The results indicated that differences between wounded and unwounded fruits related soluble solids content, pulp firmness, titratable acidity, dry matter and IAD did not affect the incidence of M. fructicola in both cultivars. However, the interaction between dry matter and colour at the time of inoculation influenced colonisation and consequent lesion size in inoculated wounded 'Chimarrita' fruits. [ABSTRACT FROM AUTHOR]

Grain legume production is of great importance in the world economy, with soybeans being a major agricultural product. Among the main causes of crop losses are diseases caused by pathogens that infect seeds, such as Colletotrichum truncatum, Corynespora cassiicola, Sclerotinia sclerotiorum and Rhizoctonia solani. The fungicides used are not fully effective in controlling these diseases, and new control options are necessary. Photodynamic inactivation (PDI) may be an alternative. PDI consists of the association of a photosensitizer (PS), light and molecular oxygen aimed at the destruction of microbial cells. Porphyrins and their derivatives are aromatic tetrapyrrolic macrocyclic compounds with photosensitizing capacity. The aim of the present study was to evaluate the efficiency of PDI in the photoinactivation of C. truncatum, C. cassiicola, S. sclerotiorum and R. solani, using a mixture of cationic meso‐tetra‐aryl porphyrins as PS, being the first study to consider this formulation as PS in the photoinactivation of these pathogens. Assays were carried out with soybean seeds artificially inoculated with the different fungi, treated with the PS at 10, 50, 100 and 200 μg/ml and submitted to light under an irradiance of 50 mW/cm2. The assays were set up following the blotter test methodology. The evaluations showed significant reductions in the infection rates of the seeds in relation to the controls. The greatest reductions were 46% for C. truncatum, 95.5% for S. sclerotiorum, 87% for C. cassiicola and 92% for R. solani. The results suggest that PDI can be an important alternative to current control methods against these pathogens. [ABSTRACT FROM AUTHOR]

BACKGROUND Asian soybean rust, caused by Phakopsora pachyrhizi, is mostly controlled by demethylation inhibitor ( DMI) and quinone outside inhibitor ( QoI) fungicides. Mutations in the cytochrome b ( CYTB) gene can lead to pathogen resistance to QoIs. The occurrence of the mutations in codons 129, 137 and 143 in the CYTB gene was investigated, and a pyrosequencing assay was developed for rapid and quantitative detection of the F129L mutation. RESULTS Molecular analysis of the CYTB gene showed the presence of the F129L mutation in field samples and monouredinial isolates, while other mutations ( G143A and G137R) were not found. The pyrosequencing was an effective method for quantitative detection of the F129L mutation, and many of the P. pachyrhizi samples showed high frequency of F129L. CONCLUSION This is the first report of the occurrence of the F129L mutation in P. pachyrhizi. The practical relevance of this mutation for field efficacy of QoIs needs further investigation. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Pathology is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study assessed the efficacy of phosphites,Trichothecium roseum(TR) and a combination of phosphites andTRcompared with lime sulphur (LS) to control brown rot, caused byMonilinia fructicola, in an organic orchard with high inoculum pressure under subtropical conditions in Brazil. The treatments were applied from blossom to harvest on two peach cultivars (‘Granada’ and ‘Chimarrita’) during 2005 and 2006. Disease incidence was assessed from full bloom to post-harvest. Two other experiments were performed under post-harvest conditions using mature fruit harvested from organic and conventional orchards and inoculated with 106conidia mL−1ofTRfollowed byM. fructicola. The incidence of blossom blight ranged from 25% to 64% on flowers collected from untreated controls, whereas all treatments reduced blight over both cultivars and years. For ‘Chimarrita’, disease incidence reached 8% in mature fruit on the tree and 43% on fruit post-harvest. In both years,TRtreatment reduced fruit infection by 50% and 63% during the growing season and post-harvest, respectively, when compared with untreated trees. ‘Granada’ did not set enough fruit to be assessed. TheTRapplied as a post-harvest treatment to fruit also significantly reduced final disease incidence. Applications ofTRcombined with phosphites or lime-sulphur were not better thanTRapplied alone, andTRwas equivalent to LS, indicating that both treatments have the potential to reduce brown rot in organic peach production. [ABSTRACT FROM PUBLISHER]

The implementation of integrated production (IP) in a peach orchard, cultivar Chimarrita, in Araucária-PR, was compared to producer's area system (CP), recommended by technicians of that region. The IP adoption impact was assessed by nutritional aspects, productivity maintenance and damage to fruits. Each area was composed of four lines, two central lines in each system were divided in four blocks of eight plants (2/block), evaluated in two seasons. Data was modeled by a generalized linear model with Poisson and Negative Binomial distributions for the response variables. IP system recommended minimum soil cultivation, green pruning, pesticides use according with pest and diseases monitoring, fertilization based on leaf and soil analysis, green cover in interlines. During harvest, the number, caliber and weight of healthy fruits were determined and also the percentage of damaged fruits was discriminated according to the cause. The IP system reduced 30% of pesticides use compared to CP, although higher incidence of brown rot in the first year occurred and no different in the subsequent year; the main pests were kept under control. IP is feasible for Araucaria maintaining productivity in the evaluated years. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Pathology is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)