Reduce Fungicide Use Research Articles

Fusion of Deep Convolution and Shallow Features to Recognize the Severity of Wheat Fusarium Head Blight.

A fast and nondestructive method for recognizing the severity of wheat Fusarium head blight (FHB) can effectively reduce fungicide use and associated costs in wheat production. This study proposed a feature fusion method based on deep convolution and shallow features derived from the high-resolution digital Red-green-blue (RGB) images of wheat FHB at different disease severity levels. To test the robustness of the proposed method, the RGB images were taken under different influence factors including light condition, camera shooting angle, image resolution, and crop growth period. All images were preprocessed to eliminate background noises to improve recognition accuracy. The AlexNet model parameters trained by the ImageNet 2012 dataset were transferred to the test dataset to extract the deep convolution feature of wheat FHB. Next, the color and texture features of wheat ears were extracted as shallow features. Then, the Relief-F algorithm was used to fuse the deep convolution feature and shallow features as the final FHB features. Finally, the random forest was used to classify and identify the features of different FHB severity levels. Results show that the recognition accuracy of the proposed fusion feature model was higher than those of models using other features in all conditions. The highest recognition accuracy of severity levels was obtained when images were taken under indoor conditions, with high resolution (12 MB pixels), at 90° shooting angle during the crop filling period. The Relief-F algorithm assigned different weights to the features under different influence factors; it made the fused feature model more robust and improved the ability to recognize wheat FHB severity levels using RGB images.

Mechanisms by which fungicides increase grain sink capacity and yield of spring barley when visible disease severity is low or absent

Abstract Fungicides are a central component of disease management programmes in many cereal production systems worldwide, but intensive use has led to problems with the evolution of resistance in pathogen populations, harmful effects on non-target organisms and residues in the food chain and environment. Better targeting of fungicide applications, according to the likely response of the crop, would help improve the sustainability of disease management, but decision making is hindered by our poor understanding of the mechanisms by which fungicides influence crop yield. This study investigated possible mechanisms responsible for yield increases following fungicide treatment of spring barley with little or no visible disease. Field experiments conducted over six site-years in the UK quantified the effects of the protectant fungicide chlorothalonil (Chl), and systemic fungicides prothioconazole (Pro) and pyraclostrobin (Pyr), applied on their own or in combination. The severity of visible disease in the absence of fungicide treatments was minimised by growing varieties with good disease resistance. Contrasting fungicide chemistries led to different effects on yield. There were two components to the yield increases. The first involved an increase (4.3–7.5 %) in grain number m−2 and was elicited by Pro and Pyr, but not Chl. The second was a smaller increase (3.7–4.6%) in mean grain weight (MGW) and was elicited by each of the fungicides tested. The effect of the triazole (Pro) and strobilurin (Pyr) on grain number was not the result of the control of visible disease pre-anthesis or an increase in photosynthetically active radiation (PAR) interception. Nor was it the result of the control of asymptomatic pathogen infection or possibly leaf surface saprophytes, because Chl gave equivalent control without increasing grain number. Our results are consistent with the hypothesis that triazoles and strobilurins can increase grain sink capacity through direct physiological effects in the field. These apparent physiological effects differ from those reported for wheat as they occur pre-anthesis and are not associated with delayed leaf senescence and resulting increased PAR interception. Application of Pro + Pyr increased radiation use efficiency (RUE), estimated over the whole season, by around 10 % compared to untreated controls and 6 % compared to Chl treated crops. Evidence is presented to show that whilst the average yield response to Pro + Pyr in the absence of disease was around 3 %, the response varied widely between sites and years. Where effects on grain number do occur, they can be elicited in a range of varieties by a single application made at booting. We argue that benefiting from physiological effects of triazole and strobilurin fungicides on spring barley yield, through appropriate timing of application, is compatible with strategies to target and reduce fungicide use in this crop.

A utilização de fungicida no cultivo de aveia: uma revisão integrativa da literatura

A utilização de agrotóxicos e o modelo atual de desenvolvimento agrícola é responsável por impactos, danos ambientais e saúde. Para que a produção de grãos seja satisfatória, o uso correto de técnicas de manejo se constitui em fator decisivo no desenvolvimento e colheita de grãos. O cultivo e consumo da aveia branca tornou-se evidente nos últimos anos devido a sua versatilidade, porém, é uma cultura sensível a variações ambientais acometida por doenças fúngicas. Esta pesquisa objetivou analisar produções científicas publicadas em periódicos nacionais e internacionais sobre cultivo de aveia branca com redução do uso do agrotóxico, garantia de cultivo sustentável ao meio ambiente e segurança alimentar. A partir da pergunta: “O que tem sido publicado na literatura nacional e internacional sobre o cultivo de aveia branca para consumo humano com o uso reduzido de fungicida?”. Com os seguintes descritores: (Fungicide AND “avena sativa”) nas bases de dados WEB OF SCIENCE (coleção principal) e SciVerse Scopus (SCOPUS), SCIENCE DIRECT e MENDELEY. Total de 312 artigos encontrados e 15 selecionados e lidos na íntegra. Os resultados indicam que independente do uso ou não de fungicida a resistência genética das cultivares ás doenças fúngicas se constitui o fator decisivo para o cultivo.

Reduced fungicide use in the nursery improves post-planting productivity of Pinus radiata for at least six years

The fertilisers and fungicides used in tree nurseries to stimulate growth and provide disease protection are an important component of conventional nursery management. However, it has been demonstrated that the ectomycorrhizal (ECM) fungi associating with Pinus radiata D. Don seedlings in the nursery can be significantly affected by increasing exposure to these products, driving reductions in the relative proportion of the ECM species most positively correlated with seedling nutrient uptake. Increasing fungicide exposure was also shown to reduce seedling size. To determine the significance of these effects on post-nursery performance, 2592 P. radiata seedlings were randomly selected from within treatment plots in this nursery chemical exposure trial and established at a site in Kaingaroa Forest, New Zealand. Assessments of the ECM community present on the trees in the plantation determined that after two years there was no longer any effect of the nursery treatments, likely due to the homogenising effect of the site conditions. Over six years the performance of the trees in the plantation was not affected by the extent of fertiliser application during their time in the nursery, but decreased nursery fungicide use had slight positive legacy effects on both tree survival and diameter growth. These gains combined to produce a significant increase in plot level basal area with reduced nursery fungicide use. Further analysis incorporating the effect of thinning on stand dynamics reinforced the potential gains in the forest from reduced fungicide use in the nursery, and the lack of benefit from fertiliser use. Based on the data collected following trial establishment, it was concluded that the observed differences in tree performance were likely driven by the impact of the ECM communities initially associated with the seedlings at planting. While the authors strongly recommend any reductions in P. radiata nursery fungicide use be considered carefully due to ongoing issues with fungal pathogens in these monoculture systems, the potential for improved nursery and plantation performance is significant and should be explored more widely.

The relationship between features enabling SDHI fungicide binding to the Sc-Sdh complex and its inhibitory activity against Sclerotinia sclerotiorum.

A new generation of succinate dehydrogenase inhibitors (SDHIs) with high efficiency and broad-spectrum antifungal activity has been frequently used in crop production. Sclerotinia stem rot is a major disease of various plants and crops caused by Sclerotinia sclerotiorum. Although benzovindiflupyr and isopyrazam reportedly have high activity against S. sclerotiorum, little is known about the bioactivity of different SDHIs classes against S. sclerotiorum or the mechanism of their differential antifungal activity. The in vitro tests revealed that the pyrazole-4-carboxamides of SDHIs (benzovindiflupyr, isopyrazam, fluxapyroxad, pydiflumetofen) had the highest activity against S. sclerotiorum followed by pyridine carboxamides (boscalid), pyridinyl-ethyl benzamides (fluopyram) and thiazole carboxamides (thifluzamide), and of these thifluzamide showed poor antifungal activity with EC50 values greater than 6.01 mg L-1 . The pyrazole-4-carboxamides of SDHIs showed satisfactory protective and curative activity against Sclerotinia stem rot. After treatment with the pyrazole-4-carboxamides of SDHIs, mitochondrial function in S. sclerotiorum decreased significantly. The enzyme activity assays revealed a lower affinity between thifluzamide and the Sc-Sdh complex than was observed for the other six fungicides, with IC50 values ranging from 0.0036 to 1.2088 μmol L-1 . Additionally, the docking positions of fungicides were similar, yet binding energies were different in the docking study with the Sdh complex. The correspondingly weaker hydrogen bonds may be responsible for the poor activity of thifluzamide against S. sclerotiorum. Understanding different binding features of various SDHIs classes with the Sc-Sdh complex might be beneficial for the design and development of highly effective broad-spectrum fungicides to ensure high yield and quality in crops by reducing fungicide use. © 2020 Society of Chemical Industry.

Potential of NanoPro to reduce fungicide rate for control ofMicrodochium nivaleon an annual bluegrass (Poa annua) green

This is a report on the potential of NanoPro™to reduce the rate of two commonly used fungicides for control of Microdochium patch (Microdochium nivale), the economically most important turfgrass disease in Scandinavia. The experiment was conducted from 14 Sept. 2018 to 1 May 2019 on an annual bluegrass golf green at the NIBIO Turfgrass Research Center Landvik. Use of NanoPro™at a rate of 292 ml/ha in tank mixture with the systemic fungicide Delaro® SC 325 or/and the contact fungicide Medallion® TL produced the same level of disease control with a 30-60% reduction in fungicide dosage as with full fungicide dosage without additive. NanoPro™was more effective with Medallion® TL than with Delaro® SC 325. We conclude that NanoPro™may have a big potential in Scandinavia and other countries where authorities require reduced fungicide use. The experiment should be repeated one more year before giving final recommendations.

Does minimal pruning and reduced fungicide use impact spiders in the grapevine canopy?

Agricultural management should aim at high densities of beneficial organisms such as spiders. Here, we asked whether spiders in vineyards can be promoted either by using novel disease resistant grape varieties that allow for a reduced number of fungicide applications, or by minimal pruning which enhances the structural complexity of the grapevine canopy. We compared spider communities in vineyards planted with fungus-resistant varieties (PIWIs) to vineyards with traditional grapevine varieties, and minimally pruned vineyards to vertical shoot positioned vineyards. Densities of Theridiidae were more than doubled in fungus-resistant grape varieties, but the remaining families were not significantly affected. Minimal pruning enhanced Philodromidae and Dictynidae but reduced Salticidae. However, neither pruning method, nor the reduced fungicide use in PIWI vineyards, had significant effects on overall spider abundance or species richness. Hence, effects of vineyard management were family-specific and possible consequences for pest regulation will thus depend on the pest control potential of the involved families.

Synergy between Cu-NPs and fungicides against Botrytis cinerea

Combating drug-resistance is a daunting task, especially due to the shortage of available drug alternatives with multisite modes of action. In this study, the potential of copper nanoparticles (Cu-NPs) to suppress 15 Botrytis cinerea isolates, which are sensitive or resistant to fungicides, alone or in combination with conventional fungicides, was tested in vitro and in vivo. Sensitivity screening in vitro revealed two fungicide resistance phenotypes, resulting from target site mutations. DNA sequencing revealed three B. cinerea isolates highly resistant to benzimidazoles (BEN-R), thiophanare methyl (TM), and carbendazim, bearing the E198A resistance mutation in the β-tubulin gene, and four isolates highly resistant to the QoI pyraclostrobin (PYR-R) with a G143A mutation in the cytb gene. Cu-NPs were equally effective against sensitive and resistant isolates. An additive/synergistic effect was observed between Cu-NPs and TM in the case of BEN-S isolates both in vitro and when applied in apple fruit. A positive correlation was observed between TM and TM + Cu-NPs treatments, suggesting that an increased TM availability in the target site could be related with the observed additive/synergistic action. No correlation between Cu(OH)2 and Cu-NPs sensitivity was found, indicating that different mechanisms govern the fungitoxic activity between nano and bulk counterparts. A synergistic profile was observed between Cu-NPs and fluazinam (FM) - an oxidative phosphorylation inhibitor - in all isolates regardless of resistance phenotype, suggesting that ATP metabolism could be involved in the mode of action of Cu-NPs. Furthermore, the observed cross sensitivity and antagonistic action between Cu-NPs and NaCl also provided evidence for copper ions contribution to the fungitoxic action of Cu-NPs. The results suggested that Cu-NPs in combination with conventional fungicides can provide the means for an environmentally safe, sustainable resistance management strategy by reducing fungicide use and combating resistance against B. cinerea.

Response of PIWI grapevine cultivars to downy mildew in highland region of southern Brazil

Downy mildew (DM) caused by Plasmopara viticola is a major grapevine disease in southern Brazil. Control of DM requires frequent fungicide treatments or the use of resistant cultivars. The pyramiding of previously identified resistance loci allows the selection of genotypes with combined resistance loci in order to build up sustainable resistance. The objective of this study was to evaluate the resistance response of PIWI cultivars Felicia, Bronner, and Calardis Blanc, containing Rpv3.1, Rpv10, and Rpv3.1 + Rpv3.2 loci, respectively, and two advanced breeding selections (ABS) containing the Rpv1 + Rpv3.1 pyramided, to the development of DM temporal dynamics. The experiment was conducted at an experimental vineyard in the highland of southern Brazil, during the 2016/2017 and 2017/2018 growing seasons. The genotype UFSC-2012-1-24 without resistance loci was used as susceptible control. DM incidence and severity were assessed biweekly from the first symptoms appearance until harvest. The cultivars and ABS were compared based on the following DM epidemiological parameters: a) beginning of symptoms appearance (BSA); b) maximum disease incidence and severity (Imax, Smax); c) time to reach maximum disease incidence/severity (TRMDI and TRMDS); and d) areas under incidence and severity disease progress curves (AUIDPC and AUSDPC). In general, there were significant differences in the estimated parameters depending on the genotype. The principal epidemiological variables that differentiated the PIWI cultivars were Smax and AUSDPC. The PIWI cultivars showed significantly lower Smax and AUSDPC of DM in comparison to the susceptible control in both 2016/2017 and 2017/2018 growing seasons. There were also significant differences between the cultivars for AUIDPC and AUSDPC in both growing seasons. Felicia cultivar showed the highest AUIDPC and AUSDPC in the 2016/2017 growing season. Surprisingly, in the growing seasons 2017/2018, Calardis Blanc displayed an increase in disease incidence and severity, showing a similar AUIDPC and AUSDPC to Felicia cultivar. In general, Bronner cultivar was the most resistant to DM. The ABS showed the lowest value of Imax, Smax, AUIDPC and AUSDPC, suggesting the effectiveness of the Rpv1 + Rpv3.1 pyramiding. The PIWI cultivars showed partial resistance to DM and are potential options for reducing fungicide use. The results showed that the pyramiding of resistance loci is fundamental to increase the genetic resistance to DM.

Maintaining product quality in raisins throughout the introgression of powdery mildew resistance

ABSTRACT The availability of powdery mildew-resistant raisin accessions will lower grower production costs and enhance the environment through reduced fungicide use. To achieve this objective, backcrossing has been employed with Vitis romanetii as the source of non-race-specific powdery mildew resistance. Initial crosses of powdery mildew-resistant F1 hybrid B36-45 with seeded raisin cultivars ‘Rangspray’ and ‘Raisin de Palestine’ yielded seedless powdery mildew-resistant first-generation backcross selections C87-41 and C87-106, which were used to develop second-generation backcross populations. Principal component analyses consistently identified ‘wrinkle,’ ‘meatiness,’ ‘product attractiveness’ and ‘skin persistence’ as being the quality characteristics most important in discriminating among powdery mildew-resistant raisin accessions and commercial raisin cultivars. Raisin quality ratings were much improved across most evaluated characters in second-generation backcross families as compared with parental powdery mildew- resistant accessions C87-41 and C87-106. After two generations of backcrossing, powdery mildew-resistant raisin selections were identified with product quality characteristics similar to those of commercial raisin cultivars.

Evaluation of a Petroleum‐Derived Spray Oil for Control of Microdochium Patch and Turfgrass Spring Performance on Nordic Golf Greens

Core Ideas Mineral oil was as effective as or more effective than fungicides in controling Microdochium patch. Repeated applications of mineral oil in autumn might inhibit turfgrass green‐up in spring. Mineral oil can reduce conventional fungicide use on Nordic golf courses. Greenkeepers are looking for alternatives to fungicides for control of turfgrass diseases. Our objective was to evaluate a petroleum‐derived spray oil with a blue‐green pigment for control of Microdochium patch/pink snow mold (Microdochium nivale) on golf course putting greens with various durations of snow cover. The spray oil was applied at rates 27 or 54 L ha−1 every third week from late August or September to December, either alone, in tank mixture with potassium phosphite (3 kg PO3 ha−1) or in tank mixture with half rate of fungicides approved for turf, in five 1‐yr trials in the Nordic countries. The oil was as effective or more effective than fungicides and gave, on average, 94 and 98% disease control at rates 27 and 54 L ha−1, respectively. Tank mixtures with half rate of prochloraz + propioconazole and fludioxonil did not increase disease suppression in a trial with 79 d snow cover. Phosphite reduced disease severity in one trial only and did not improve disease control or turfgrass quality when tank‐mixed with the oil. The pigment in the spray oil was highly persistent and improved turfgrass greenness except in a trial where the combination of oil and ice cover gave a transitory black color at ice melt. Another trial with long snow cover showed a drop in turfgrass quality in spring as the spray oil prevented normal green‐up. In conclusion, this research shows that a spray oil has the potential to reduce fungicide use on Nordic golf courses.

New Zealand Plant Protection Medal 2016

This medal is awarded by the New Zealand Plant Protection Society to honour those who have made exceptional contributions to plantprotection in New Zealand in the widest sense. The medal is awarded for outstanding services to plant protection, whether through research,education, implementation or leadership. 
 In 2016, the New Zealand Plant Protection Medal was awarded to Dr Rob Beresford who is one of New Zealand’s most experienced and versatile plant pathologists. Rob started his career in science with an MSc Hons, 1st class, in Auckland in 1978 and was appointed to DSIR Plant Diseases Division at Lincoln in 1979. He was awarded a National Research Advisory Council Postgraduate Research Fellowship to undertake PhD studies at Long Ashton Research Station in the UK from1982 to 1985, returning to Lincoln in 1986. Those studies kicked off a long career in epidemiology and today Rob is New Zealand’s pre-eminent plant disease epidemiologist. For 30 years, Rob has been New Zealand’s strongest advocate for the use of weather-based disease prediction for developing practicaldisease control strategies, particularly to reduce the economic, environmental and market residue impacts of fungicide use. By understanding and modelling relationships between pathogen biology and ecology and weather, Rob has translated complex correlations between biological and physical factorsinto simple practical tools for growers to use for disease control. To date, these have included decision support tools for apple scab, downy mildew in onions, botrytis in grapes and more recently Psa in kiwifruit. He has also developed prediction models for climatic risk of invasive pathogens (potato wart disease and myrtle rust) and for the impacts of climate change on crop diseases. 
 Recognising the importance of climate and weather in affecting plant diseases, Rob has, for many years, championed a network of weather stations in the key horticultural districts throughout New Zealand to generate data for the decision-support tools. It has been a struggle to keep the network running against shortages of funding and the frequent need to re-assert the value of the network to New Zealand horticulture. Rob has built a team of equally committed colleagues who share this understanding and, through tenacity and persistence, have recently achieved an upgrade of the entire network to internet-based communication systems. It is through his close collaborations over many years with the software company HortPlus that his decision support tools have been delivered to the commercial arena. 
 Rob was a member of the New Zealand team that argued the case at the World Trade Organisation for the easing of restrictions on New Zealand apples entering Australia. Rob’s superior skills in interpreting climate data, in this case Australian data, in terms of pathogen survival, establishment and spread, and his clarity in presenting the results were instrumental in the success of that case in 2010.
 In parallel with Rob’s epidemiological strategy to reduce fungicide use is his interest in the threat of pathogens developing resistance to fungicides. Rob leads research to identify resistance threats to fungicides and also provides liaison between grower associations and agrochemical companies to design and implement robust resistance-management strategies. His focus on resistance started in 2005 when he published updated management strategies for all nine of the then available fungicide groups for the New Zealand Plant Protection Society (NZPPS). In 2007, he re-established the New Zealand Committee on Pesticide Resistance (NZCPR) (which had been in abeyance for 10 years) and chaired the committee’s work on fungicides, insecticides and herbicides from 2007 to 2012. He stepped aside to become NZCPR Science Advisor in 2012 so he could focus on resistance research. Following devastating disease outbreaks of apple scab (Venturia ineaqualis) in the pipfruit industry in 2009, Rob initiated a research programme with Pipfruit New Zealand that showed the cause of the outbreaks to be resistance to two groups of fungicides in use at the time. He has recently coordinated resistance strategy updates for botrytis affecting the wine industry, for summer fruit diseases and is currently leading a programme to monitor resistance of grape powdery mildew to key groups of fungicides. Rob was awarded the 2014 Plant & Food Research Chairman’s Award for his work on fungicide resistance.
 Rob is an effective communicator at all levels from heavy science to grower forums and is always willing to share his time, skills and knowledge. He has been involved with undergraduate lecturing for many years and has successfully supervised several PhDs.
 NZPP Medal recipients for the previous five years:2015: Gary Barker2014: -2013: Andrew Hodson2012: Margaret Dick2011: Jim Walker

The trade-off between grape yield and grapevine susceptibility to powdery mildew and grey mould depends on inter-annual variations in water stress

Reducing plant growth to limit their susceptibility to diseases has been proposed as a way to reduce pesticide use, but reducing crop growth may have detrimental effect on yield. In this paper, we test the hypothesis of a trade-off between maintaining grape yield and reducing grapevine susceptibility to powdery mildew (Erysiphe necator) and grey mould (Botrytis cinerea), two major diseases of the grapevine (Vitis vinifera L.). Grapevine susceptibility to these two diseases was measured by relevant features of grapevine vegetative development identified in previous studies: leaf biomass at flowering for powdery mildew and pruning mass for grey mould. Data were collected during a 3-year field experiment in a vineyard located in the south of France, in which pests and disease were controlled by spraying pesticides. The two pathogens studied in this paper were chosen because they differ in terms of their biology (biotroph vs necrotroph) and their interaction with the grapevine (the highest grapevine susceptibility occurs early in the cycle for powdery mildew and late in the cycle for grey mould), in order to give genericity to the results. Results confirmed the hypothesis of a trade-off between maintaining grape yield and reducing grapevine susceptibility to both pathogens through reduced vegetative growth, but provided evidence that win–win situations (high yield, low susceptibility) do exist. Moreover, we found a synergy between reducing grapevine susceptibility to powdery mildew and grey mould. These results suggest opportunities to reduce fungicide use when a win–win situation occurs as the risk of yield and quality losses may be lower in those years. Inter-annual variation in water stress at flowering was found to be a key driver of the balance between grape yield and grapevine susceptibility to both pathogens through their effect on the source–sink balance of the grapevine. Water stress at flowering appeared as a relevant indicator to inform the probability of occurrence of a win–win situation. Our results suggest that it could also be used to adapt management practices like irrigation, cover cropping or a combination of both, to reach a win–win situation. The relevance of these findings to vineyards in similar semi-arid environments is discussed.

Unraveling the mechanisms used by antagonistic yeast to control postharvest pathogens on fruit

Biological control using microbial antagonists is one of the most promising alternatives for reducing fungicide use during the postharvest life of fruits. To date, there are hundreds of reports about using yeast antagonists to control biologically postharvest diseases. Very few of these antagonists, however, have reached the commercial development stage and launched as commercial products. In most cases, there are inherent problems in the biocontrol systems related to poor performance and inconsistency under commercial conditions. Among the reasons for these shortcomings is the lack of understanding of mechanisms of actions of these BCAs. A deep understanding of the mode of action is essential to develop appropriate formulation and methods of application, and to obtain registration. In recent years, there has been a phenomenal advancement in the use of molecular techniques contributing to the development of innovative tools for improving knowledge on the antagonistic mechanisms of BCAs. In particular, the omics techniques are providing a powerful tool to dissect the complex interactions between the antagonist, the pathogen, the fruit host, the natural microflora, and the environmental conditions.

Durable Late Blight Resistance in Potato Through Dynamic Varieties Obtained by Cisgenesis: Scientific and Societal Advances in the DuRPh Project

Abstract From 2006 through 2015, a research project on Durable Resistance in potato against Phytophthora (DuRPh) was carried out at Wageningen University and Research Centre. Its objective was to develop a proof of principle for durable resistance against late blight by cisgenesis. This public-funded project aimed at stimulating research on genetic modification and public debate on innovative genetic techniques. It was decided to clone and transfer late blight resistance (R) genes of crossable wild potato species (cisgenes) by Agrobacterium tumefaciens-mediated transformation without non-potato genes. A stack of multiple R genes were planned to be inserted into established varieties, thereby creating a dynamic variety in which the composition of the stacks may vary over space and time. Cisgenic plants were selected based on the expression of all inserted R genes and trueness-to-type. Within the project, 13 R genes from wild potato species were genetically mapped and three of them were cloned. Four varieties were transformed with one to three R genes. This was initially done using kanamycin resistance provided by a selectable marker gene of synthetic origin in order to quickly test the performance and stability of the introduced R genes and stacked R gene combinations. Once the functioning thereof was confirmed, marker-free transformations were conducted; thus, true cisgenic events were selected. The results about the different R genes, their chromosomal location, their specificity, the background dependence, the maximum size of a stack, its regeneration time and associated somaclonal variation frequency and its stability were studied. After selection and characterisation in the laboratory, the best cisgenic events were assessed in field trials for late blight resistance. This showed that inserted R genes were capable of turning a susceptible variety into a resistant one. Maximising longevity of the resistance was assured through resistance management research. It was shown that stacking of multiple R genes and monitoring how to deploy these stacks spatially and temporally could reduce fungicide use by over 80%. Communications through media and field demonstrations were manifold to allow public and policymakers to decide if cisgenesis is an acceptable tool to make potato farming more sustainable. Future deployment of the DuRPh strategy will depend largely on its status as a genetically modified crop or its exemption thereof. Worldwide near eradication of late blight would increase global annual potato production by close to 80 million tons, thereby contributing considerably to the needed additional global future food supply.

Antifungal Activity of Volatile Compounds Produced by an Edible Mushroom Hypsizygus marmoreus against Phytopathogenic Fungi

AbstractVolatile compounds with antifungal activity produced by edible mushrooms have potential as biological control agents to combat fungal diseases and reduce fungicide use in agriculture. Here we investigated the antifungal activity of volatile compounds produced by the edible mushroom Hypsizygus marmoreus (TUFC 11906) against eight phytopathogenic fungi. The results showed that volatile compounds from the mycelia and culture filtrates (CFs) of H. marmoreus had antifungal activity against some phytopathogenic fungi. Among them, the mycelial growth and conidial germination of Alternaria brassicicola were significantly inhibited by 60 and 100%, respectively. Moreover, the volatile compounds from CFs inhibited the lesion formation of A. brassicicola on detached cabbage leaves by 94%. The volatile compounds had higher antifungal activity against A. brassicicola than other fungi. With the removal of the volatile compounds from conidia of A. brassicicola, the conidia began to germinate, which indicates fungistatic activity of the compounds. The volatile compounds were isolated from the CFs of H. marmoreus, and the major volatile compound with antifungal activity was estimated to be 2‐methylpropanoic acid 2,2‐dimethyl‐1‐(2‐hydroxy‐1‐methylethyl)propyl ester. As the volatile compound produced by H. marmoreus is a product of an edible mushroom and has fungistatic activity against some phytopathogenic fungi, especially A. brassicicola, it may be possible to use the compounds as a novel safe agent for protecting crops in the field and during storage.

Fungicide strategies for the control of turfgrass winter diseases

It is a goal of the turf industry to reduce fungicide use, maximize fungicide efficacy, and minimize the risk of fungicide resistance. Based on these integrated pest management principles and current fungicide labels, our objective was to elucidate the optimal use of propiconazole (Banner Maxx, 156 g a.i. L–1), azoxystrobin + propiconazole (Headway, 62.5 + 104 g a.i. L–1), and fludioxonil (Medallion TL, 104 g a.i. L–1) for the control of the winter-active pathogens Micordochium nivale and Typhula incarnata. Five experiments were conducted on greens and fairways at four sites in Norway and Sweden during the winter seasons of 2011–2012 and 2012–2013. Iprodione (Chipco Green, 250 g a.i. L–1), which was used in Scandinavia until 2009 and is still a widely used fungicide internationally, was included in two experiments. One application of propiconazole (468 g a.i. ha–1) or azoxystrobin + propiconazole (187.5 + 312 g a.i. ha–1) in October controlled 80% of the microdochium patch, and the control of both microdochium patch and typhula blight usually exceeded 90% if the first application of one of these fungicides was followed by at least one application of fludioxonil (375 g a.i. ha–1) before snow cover. After an initial application of propiconazole or azoxystrobin + propiconazole in October, two applications of fludioxonil in late autumn were more efficient in improving visual turf quality in spring than one application of fludioxonil in autumn plus one application of propiconazole just after snow melt in spring. Fludioxonil gave the same level of control of microdochium patch as iprodione despite a much lower use of the active fungicide ingredient. In conclusion, one application of propiconazole or azoxystrobin + propiconazole while the turf is still growing, followed by one applications of fludioxonil after growth cessation, will usually provide adequate control of the winter diseases in turfgrass.

Adapting Value for Cultivation and Use testing to stimulate the release of improved varieties for the organic sector. The case of spring wheat in The Netherlands

Value for Cultivation and Use (VCU), the mandatory variety testing system for agricultural crops in the European Union (EU), has been used as a policy instrument by favouring the release of variety types that enable socially desirable developments, such as reducing fungicide use. With this paper, we aim to assess whether VCU can be used to enhance the availability of varieties suitable to organic farming. Therefore, we analyse data of an organic spring wheat VCU project that was conducted between 2001 and 2004 at three locations in the Netherlands. Varieties selected through organic VCU were clearly more suitable for organic production than those registered through the conventional procedure. However, new varieties could not match the baking quality of the organic standard variety. We conclude that enhancing the number of suitable varieties for the organic sector requires adapting both conventional breeding programmes as well as the VCU system.

Econometric Analysis of Grading Standards: The Ordered Fractional Approach

AbstractWe present a method for estimating the quality of production when quality is measured by discrete grades and is thus both ordinal and fractional. Monte Carlo experiments indicate that our method estimates average partial effects of quality determinants more accurately than linear estimators, and provides estimates with low bias even with weak instruments. An application of the model to wheat production in Japan demonstrates the importance of disease control in determining wheat grade. Weather variable coefficients suggest that climate change could actually improve wheat quality in Japan, thereby allowing farmers to reduce fungicide use and other inputs, as well as switch varieties.

Cultivo protegido de videira: manejo fitossanitário, qualidade enológica e impacto ambiental

O cultivo protegido na cultura da videira apresenta-se como uma alternativa na diminuição da incidência de doenças fúngicas em regiões que apresentam excesso de chuvas. A utilização de cobertura plástica sobre as linhas de cultivo da videira ocasiona modificações no microclima ao redor da planta, principalmente pela ausência de água livre sobre folhas e frutos. Estas alterações propiciam condições desfavoráveis ao desenvolvimento de doenças fúngicas, com a menor necessidade do uso de fungicidas, como as podridões de cachos, que atualmente são um dos maiores problemas no controle fitossanitário, em regiões produtoras tradicionais, como a Serra Gaúcha. Todavia, o oídio da videira que outrora não apresentava incidência em condições de alta umidade relativa, em condições de cultivo protegido, deve ser monitorado. Outro aspecto que merece cautela é o uso de fungicidas, pois destaca-se que, pela redução de radiação ultravioleta e ausência de chuvas sobre os cachos, devido ao uso da cobertura plástica, o período residual dos fungicidas é prolongado. Este maior acúmulo é preocupante, tanto nas uvas destinadas ao consumo in natura, que afeta diretamente o consumidor, quanto às destinadas à vinificação, que prejudica a atuação das leveduras na fermentação dos vinhos. De forma geral, a tecnologia de cobrimento dos vinhedos é eficaz no controle de doenças fúngicas e na redução do uso de fungicidas, contudo deve ser considerada como um novo sistema de produção, principalmente por exigir um manejo fitossanitário distinto em relação ao cultivo convencional. Os plásticos de cobertura, usados, devem ser considerados resíduo agrícola, exigindo cuidados específicos para que seja evitada contaminação ambiental.