scholarly journals MULTI-PURPOSE CHESTNUT CLUSTERS DETECTION USING DEEP LEARNING: A PRELIMINARY APPROACH

2019 ◽  
Vol XLII-3/W8 ◽  
pp. 1-7 ◽  
Author(s):  
T. Adão ◽  
L. Pádua ◽  
T. M. Pinho ◽  
J. Hruška ◽  
A. Sousa ◽  
...  
Keyword(s):  
Phytophthora Cinnamomi ◽  
Agricultural Practices ◽  
Castanea Sativa ◽  
Cryphonectria Parasitica ◽  
Nutritional Deficiencies ◽  
Strong Increase ◽  
Environmental Disaster ◽  
Gall Wasp ◽  
European Chestnut ◽  
Portuguese Economy

<p><strong>Abstract.</strong> In the early 1980′s, the European chestnut tree (<i>Castanea sativa, Mill.</i>) assumed an important role in the Portuguese economy. Currently, the Trás-os-Montes region (Northeast of Portugal) concentrates the highest chestnuts production in Portugal, representing the major source of income in the region (€50M-€60M).</p> <p>The recognition of the quality of the Portuguese chestnut varieties has increasing the international demand for both industry and consumer-grade segments. As result, chestnut cultivation intensification has been witnessed, in such a way that widely disseminated monoculture practices are currently increasing environmental disaster risks. Depending on the dynamics of the location of interest, monocultures may lead to desertification and soil degradation even if it encompasses multiple causes and a whole range of consequences or impacts. In Trás-os-Montes, despite the strong increase in the cultivation area, phytosanitary problems, such as the chestnut ink disease (<i>Phytophthora cinnamomi</i>) and the chestnut blight (<i>Cryphonectria parasitica</i>), along with other threats, e.g. chestnut gall wasp (<i>Dryocosmus kuriphilus</i>) and nutritional deficiencies, are responsible for a significant decline of chestnut trees, with a real impact on production. The intensification of inappropriate agricultural practices also favours the onset of phytosanitary problems. Moreover, chestnut trees management and monitoring generally rely on in-field time-consuming and laborious observation campaigns. To mitigate the associated risks, it is crucial to establish an effective management and monitoring process to ensure crop cultivation sustainability, preventing at the same time risks of desertification and land degradation.</p> <p>Therefore, this study presents an automatic method that allows to perform chestnut clusters identification, a key-enabling task towards the achievement of important goals such as production estimation and multi-temporal crop evaluation. The proposed methodology consists in the use of Convolutional Neural Networks (CNNs) to classify and segment the chestnut fruits, considering a small dataset acquired based on digital terrestrial camera.</p>

Impact of the Asian gall wasp ( Dryocosmus kuriphilus ) on the radial growth of the European chestnut ( Castanea sativa ).

2021 ◽  
Author(s):  
Enrico Marcolin ◽  
Mario Pividori ◽  
Fernanda Colombari ◽  
Maria Chiara Manetti ◽  
Francesco Pelleri ◽  
...  
Keyword(s):  
Radial Growth ◽  
Castanea Sativa ◽  
Gall Wasp ◽  
Dryocosmus Kuriphilus ◽  
European Chestnut

scholarly journals The role of production site isolation in the plant health situation of sweet chestnut (Castanea sativa)

2017 ◽  
pp. 79-82
Author(s):  
Gabriella Kovács ◽  
László Radócz
Keyword(s):  
Castanea Sativa ◽  
Cryphonectria Parasitica ◽  
Western Slope ◽  
Past Century ◽  
Sweet Chestnut ◽  
European Chestnut ◽  
Disease Occurrence ◽  
New Perspective ◽  
Blight Disease ◽  
Health Situation

The most destructive pathogen for the European chestnut is the blight fungus Cryphonectria parasitica (Murr.) Barr. The spread of the fungus was very fast in Europe within a few decades in the second half of the past century. During the tree-health checking in the chestnut andwalnut plantation in Romania, Hargita county, next to Homoródkarácsonyfalva village, we especially concentraded on the signs of blight disease occurrence. The grove is laying on a western slope, under a pine forest. This favourable geographical space protects it not only from pathogen attacts, but it has a special, mild microclimate for nut and chestnut trees. The European chestnut could be a valuable member of local forests, opening a new perspective under conditions of climate changes.

scholarly journals Efficacy of biofungicides Supresivit and Polyversum against Phytophthora root pathogens on European chestnut (Castanea sativa Mill.)

2011 ◽  
Vol 31 (No. 3) ◽  
pp. 109-114
Author(s):  
G. Juhásová ◽  
S. Bernadovičová
Keyword(s):  
Trichoderma Harzianum ◽  
Mycelial Growth ◽  
Soil Fungi ◽  
Phytophthora Cinnamomi ◽  
Castanea Sativa ◽  
Pythium Oligandrum ◽  
European Chestnut ◽  
Significant Difference ◽  
Castanea Sativa Mill ◽  
Ink Disease

The effect of two commercially produced biopreparations on the originators of chestnut ink disease in Slovakia &ndash; soil fungi Phytophthora cambivora and Phytophthora cinnamomi was tested in laboratory conditions. Investigations of interrelations between Trichoderma harzianum (Pythium oligandrum) and isolates of Phytophthora sp. obtained from infected tissues of Castanea sativa Mill. proved more important inhibitive effects for Pythium oligandrum (biopreparation Polyversum) efficiency 25.3% (Ph. cambivora) and 26.2% (Ph. cinnamomi). Biopreparation Supresivit (Trichoderma harzianum) reached the efficiency 9.1% for Ph. cambivora isolates and 9.2% for Ph. cinnamomi isolates. Significant effect of the used bioformulas for inhibition of mycelial growth of both Phytophthora sp. and significant difference in the efficacy of two different bioformulas were confirmed statistically. &nbsp;

scholarly journals Population Structure and Disease Development of Cryphonectria parasitica in European Chestnut Forests in the Presence of Natural Hypovirulence

1997 ◽  
Vol 87 (1) ◽  
pp. 50-59 ◽  
Author(s):  
Martin Bissegger ◽  
Daniel Rigling ◽  
Ursula Heiniger
Keyword(s):  
Castanea Sativa ◽  
Cryphonectria Parasitica ◽  
First Year ◽  
Mating Types ◽  
Vegetative Compatibility Groups ◽  
European Chestnut ◽  
Repeated Sampling ◽  
Cryphonectria Hypovirus ◽  
Two Populations

The Cryphonectria parasitica populations in two 6-year-old European chestnut (Castanea sativa) coppices were investigated in southern Switzerland over a period of 4 years. Occurrence of white isolates indicating an infection with Cryphonectria hypovirus, vegetative compatibility groups (VCGs), hypovirulence conversion capacity, and mating types were used to characterize the populations. Sampling of randomly chosen cankers in the first year yielded 59% white isolates in one and 40% in the other population. The distribution of the VCGs and mating types was similar among white and orange isolates, indicating a homogeneous infection of the two populations by the hypovirus. Fourteen VCGs were found in the first population, 16 VCGs in the second. Altogether, 21 VCGs were determined. The same three VCGs dominated in both populations, comprising more than 60% of all isolates. Several VCGs were represented only by white isolates. Five of the six most common VCGs were clustered in two hypovirulence conversion groups, with almost 100% hypovirus transmission within each cluster. Repeated sampling of the same cankers in 1990, 1992, and 1994 did not reveal an increase of white isolates. The portion of blighted stems rose from 37% to about 60% in both plots within 4 years. In this time, chestnut blight killed 15% and competition an additional 21% of the sprouts. Predominantly, sprouts with low diameters at breast height were killed. The growth rate of new cankers was high in their first year and decreased gradually in the following years. A role of hypovirulence in the decline of disease severity was evident since (i) cankers yielding white isolates grew slower and killed considerably fewer sprouts than cankers with orange isolates; and (ii) the majority of the cankers yielded white isolates at least once during the 4-year observation period.

scholarly journals The development of population structure of Cryphonectria parasitica on European chestnut (Castanea sativa Mill.) in the Experimental Castanetarium Horné Lefantovce, observed over a 12-year study period

2009 ◽  
Vol 36 (No. 2) ◽  
pp. 55-60 ◽  
Author(s):  
K. Adamčíková ◽  
M. Kobza ◽  
G. Juhásová
Keyword(s):  
Population Structure ◽  
Castanea Sativa ◽  
Morphological Characters ◽  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Experimental Plot ◽  
Disease Symptoms ◽  
European Chestnut ◽  
Blight Disease ◽  
First Time

: We studied occurrence of chestnut blight disease in the Experimental Castanetarium Horné Lefantovce, SW Slovakia. The study ran in years 2006–2007 on a set consisting of 889 chestnut trees growing in the clonal orchard on Biological Plot 105. From this number, 857 trees were found healthy without disease symptoms. The chestnut blight disease was identified on 32 of them. The infected trees were examined for presence of pycnidia and perithecia of the causal agent. In all positive cases, the observed morphological characters indicated virulency of the obtained isolates. No hypovirulent isolate was detected on the evaluated experimental plot. In total, six vegetative compatibility (vc) types were specified in the sample consisting of 31 isolates. Our vc types corresponded to the European vc types EU 2, EU 12, EU 13, EU 14, EU 17, EU 19. Two vc types – EU 2 and EU 19 – were dominant. Vc type EU 19 accounted 35.5% and EU 2 32.2% of isolates. The vc type EU 19, which was the most frequent one in the evaluated site, was detected in Slovakia for the first time.

scholarly journals Chestnut Breeding in the United States for Disease and Insect Resistance

Plant Disease ◽  
2012 ◽  
Vol 96 (10) ◽  
pp. 1392-1403 ◽  
Author(s):  
Sandra L. Anagnostakis
Keyword(s):  
United States ◽  
Phytophthora Cinnamomi ◽  
Single Species ◽  
The United States ◽  
Cryphonectria Parasitica ◽  
Southern United States ◽  
Native Range ◽  
European Chestnut ◽  
Cultivar Selection ◽  
Nut Production

The genus Castanea (family Fagaceae) is found in north temperate climates around the world, and is highly prized in many different cultures for its nutritious nuts and valuable timber. Selection for larger, better-tasting nuts has been ongoing in Asia and Europe for centuries. Early trade routes moved European chestnut trees (C. sativa) west of their native range (in the Caucasus mountains), and the Romans then moved them across their empire to provide support posts for grapevines, as well as for the nuts. Cultivar selection in Turkey, Italy, Spain, and Portugal has been extensive, and regional favorites developed. The many uses of the wood of American chestnut made this “all purpose” tree extremely valuable in its native range in North America. Nut production was important as a food source for rural families and many species of birds and animals. The other American species in the genus Castanea are classed as chinquapins, and may be divided into several or lumped as a single species. The small nuts from these trees and bushes serve primarily as mast for wildlife. Two serious diseases of chestnut trees changed the direction of chestnut research in the United States. Ink disease, caused by the root pathogen Phytophthora cinnamomi, was discovered to be the cause of widespread death of chestnuts and chinquapins in the southern United States, which had been observed since about 1850. This imported pathogen probably came into the southern United States before 1824. The second chestnut disaster was the introduction of chestnut blight disease, which was first found in the United States in 1904. The pathogen causing the lethal cankers is an Ascomycete now known as Cryphonectria parasitica. The longest continuing chestnut breeding program in the United States is in Connecticut.

scholarly journals Histopathological study reveals new insights into responses of chestnut (Castanea spp.) to root infection by Phytophthora cinnamomi

2020 ◽  
Author(s):  
Patrícia Fernandes ◽  
Maria Helena Machado ◽  
Maria do Ceu Silva ◽  
Rita Lourenco Costa
Keyword(s):  
Phytophthora Cinnamomi ◽  
Castanea Sativa ◽  
Wall Thickening ◽  
Histopathological Study ◽  
Cortical Cells ◽  
Callose Deposition ◽  
European Chestnut ◽  
Growth Area ◽  
Cell Layers ◽  
Zoospore Suspension

The European chestnut (Castanea sativa) is threatened by the hemibiotrophic oomycete Phytophthora cinnamomi, the causal agent of ink disease. Chestnut species have different susceptibility levels to P. cinnamomi, with the Asian species (C. crenata; C. mollissima) exhibiting the highest level of resistance. A histological approach was used to study the responses exhibited by susceptible and resistant chestnut genotypes by characterizing the early stages of P. cinnamomi infection and the cellular responses it induces in roots. C. sativa (susceptible) and C. crenata (resistant) plantlets, were inoculated with a P. cinnamomi virulent isolate with a zoospore suspension or by direct contact with mycelia agar plugs. Root samples were collected at 0.5, 3.5, 24, 48, and 72 hours after inoculation (hai) for microscopic observations. Penetration was observed, in both species, at 0.5hai and 3.5hai with mycelium and zoospore inoculations, respectively. In both inoculation methods, following the penetration into the rhizodermis, P. cinnamomi hyphae grew inter- and intracellularly through the cortex and into the vascular cylinder. C. crenata cells displayed a delay in the pattern of infection, by having fewer cell layers colonized when compared with C. sativa. At 72hai, the collapse of the first layers of C. sativa cortical cells was observed, indicating the beginning of necrotrophy. C. crenata was able to respond more efficiently to P. cinnamomi than C. sativa, by restricting the pathogen’s growth area through the early activation of resistance responses, such as callose deposition around some intracellular hyphae, HR-like cell death, cell wall thickening and accumulation of phenolic-like compounds.

scholarly journals A New Clonal Propagation Protocol Develops Quality Root Systems in Chestnut

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 826
Author(s):  
Patrícia Fernandes ◽  
Sara Tedesco ◽  
Inês Vieira da Silva ◽  
Carmen Santos ◽  
Helena Machado ◽  
...  
Keyword(s):  
Clonal Propagation ◽  
Phytophthora Cinnamomi ◽  
Castanea Sativa ◽  
Breeding Programs ◽  
Continuous Growth ◽  
European Chestnut ◽  
High Incidence ◽  
Castanea Sativa Mill ◽  
Large Production

There is, at the present time, a great demand for chestnut rootstocks with improved resistance to Phytophthora cinnamomi Rands in the nurseries. New genotypes are emerging from European chestnut breeding programs and the production of thriving plants to restore old orchards with low yields due to a high incidence of diseases, namely root rot, is necessary. Micropropagation is a useful technique for clonal propagation. Nevertheless, in vitro culture propagation is genotype-dependent. Consequently, the existing protocols may demonstrate poor reproducibility and low efficacy. Thus, the need to contribute to the development of new micropropagation protocols suitable for large production of emerging genotypes. As a contribution to fill this gap, a three-step protocol was developed by using new combinations of Murashige & Skoog, Woody Plant, and adapted modified Melin-Norkrans media in different stages of the propagation process. About 90% of shoots were rooted, and after three months of acclimatization, 85% of these plants survived and were capable of continuous growth in the field. Currently, this protocol is being used in the production of several hybrid genotypes (with improved resistance to P. cinnamomi), selected from our ongoing breeding program and also in Castanea sativa Mill. and Castanea crenata Siebold and Zucc. species.

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