in what is now the area near the Black Sea of \u200b\u200bGeorgia around 10,000 years ago<\/strong> it was brought by
civilizations all over the world. Exemplary is the case of the Roman people<\/strong> who, during the conquests,
planted the vines in order not to miss the legions wine in battle. This crop has also had to defend itself, in
more recent times, from pathogens from non-European regions<\/strong> that threatened its survival, above all the
attack of Phylloxera<\/strong>.<\/p>\n
To date many of the diseases that affect the vine are prevented<\/strong> or treated by special plant protection<\/strong> Prevention plays a role of primary importance but, once the plant shows symptoms, it is crucial to identify Operationally the diseased plants were marked<\/strong> in some portions of the vineyard so that the markers were clearly visible<\/strong> from the aerial photos. <\/p>\n <\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":" WHAT ARE PLANT DISEASES? The vine has been one of the most characteristic crops of European civilization for millennia. Domesticated in what is now the area near the Black Sea of \u200b\u200bGeorgia around 10,000 years ago it was brought by civilizations all over the world. Exemplary is the case of the Roman people who, during […]<\/p>\n","protected":false},"author":4,"featured_media":4473,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"
products<\/strong>, but for some there is still no cure. Among the most important cases for the production reductions
that these pathogens impose on cultivation we find Flavescence Dor\u00e8e<\/strong> and the Esca disease<\/strong>. The first is a
phytoplasm, which is a pathogen that lives within the vascular system of plants. It is transmitted by an insect
called Scaphoideus titanus and, once the plant contracts the disease, it is destined to die in a few years. To
date no curative products are available and the only method to combat the pathogen is fighting against the
insect vector and, once the sick plants are found, their removal and combustion. Despite these precautions
and the numerous checks carried out at state level by the various members of the EU, the disease is
spreading. As for the Esca disease, instead, it is a complex interaction of innumerable fungal organisms
(about 200 are known but it is believed that they are only a part of those actually present) that deteriorate the
wood and, through the release of toxins in the vascular system of the plants, they cause a characteristic
response in the leaves of the plant, the distinctive stripes. As in the previous case, plants tend to deteriorate
in the long run and there are no curative products. However, some campaigns are being carried out by
companies and research institutes that aim to remove the diseased portions of the trunk to sanitize the plant.
The first results appear to be promising.<\/p>\n
diseased vines in order to be able to intervene promptly.
Starting from this background, T# has collected data during the 2018 growing season in Italy<\/strong> in order to be
able to program algorithms capable of identifying diseased plants. The acquisition phase took place at the
time when these two diseases showed the most of their symptoms.<\/p>\n
Subsequently, high-resolution multispectral<\/strong> images were acquired with a DJI Inspire 2 drone. Once the
orthomosaics originated, various approaches for diseased plants recognition were tested. Multiple solutions
were attempted, but none appeared to be quite reliable on its own, so an approach that considered several
factors was used. An algorithm was then developed that was able to evaluate and weigh the outputs of the
individual indices to return an accurate result in the identification of diseases. The algorithm was tested on a
series of aerial images of sick vineyards to test the adaptability and reliability of the survey under different
conditions. The results were immediately very promising although still to be refined: the accuracy settled at
around 87% with most errors concentrated on the side of false positives, i.e. sick plants are almost all
reported and some included appears healthy. During the growing season 2019 further tests will be carried
out in Italy and Europe to fully test the algorithm and to validate it thanks to ground truthing.<\/p>\nVineyard monitoring is a key aspect of precision viticulture and UAV are a reliable and smart way to gain good results, also for disease detection. In particular we want to focus on several diseases that affect worldwide viticulture, as it is Grapevine Leafroll.<\/h5>\n
Grapevine Leafroll Disease (GLD) is one of the major diseases that can affect a vine. It is caused by several viruses of the family Closteroviridae <\/em>that acts together causing the symptoms of the disease. Grapevine Leafroll-associated Virus 3 <\/em>(GLRaV-3) seems to have a pivotal role for inducing this disease.<\/h5>\n[caption id=\"attachment_4467\" align=\"alignright\" width=\"300\"]
![\"\"](\"https:\/\/terrasharp.com\/wp-content\/uploads\/2018\/04\/Leaf-roll-virus-300x225.jpg\")
Symptoms on red-berried varieties[\/caption]\nThe damage of this pathogen on global production of grapes is impressive and its importance can be compared to major fungal disease for this crop, such as Esca complex or Flavescence dor\u00e9e.<\/em><\/h5>\n
Unlike other grapevine pathogens or pests that generally come from an area outside Europe and the Middle East, these viruses originated in the Old World. In the early twentieth century the symptoms were described as a \u201credding\u201d, an abnormal leaf coloration for red-berried grapevine, which accumulated sugars and showed downward rolling of the edges. Nowadays, we know that the symptoms can vary greatly according to several factors such as grapevine cultivar, seasonal variations and climatic conditions. Some white-berried varieties are symptomless although they are infected.<\/h5>\n[caption id=\"attachment_4466\" align=\"alignleft\" width=\"300\"]
![\"\"](\"https:\/\/terrasharp.com\/wp-content\/uploads\/2018\/04\/FS1260-5-big-300x225.jpg\")
Symptoms on white-berried varieties[\/caption]\nAt the beginning of the growing season budburst and shoot development is generally delayed in time compared to healthy plants, but this condition lasts for a few weeks. First leaf symptoms appear in early-mid summer, firstly on water stressed plants; the severity of the foliar damage increases until the end of the growing season. For red-berried varieties symptomatic leaves are completely red, apart from primary and secondary veins which remains green. Only varieties that have clusters deeply pigmented show completely red leaves. For white-berried varieties the symptoms are difficult to recognise, so they are the perfect reservoir for the pathogen.<\/h5>\n[caption id=\"attachment_4468\" align=\"alignright\" width=\"300\"]
![\"\"](\"https:\/\/terrasharp.com\/wp-content\/uploads\/2018\/04\/symptoms-fig06-300x218.jpg\")
Cluster produced by an healthy vine (left) and one coming from an infected plant (right)[\/caption]\nTo prevent the spread of the pathogen in new plantations, nurseryman can adopt some techniques such as heat therapy (high temperatures for a few seconds kill the viruses and the plant is not damaged) or in vitro culture (starting from few cells disease-free a complete plant can grow in a laboratory). The use of safe plant material is extremely important. The use of unhealthy vines is the first cause of the viruses transmission.<\/h5>\n
The two other ways of pathogen spread are insects and agricultural practices. Some pests that are phloem feeders, such as mealybugs or scale insects can occasionally spread the viruses. These insects can be killed using chemicals and\/or with the introduction in the fields of other insects that are predators or use them as a feed for their offspring. An important vector for the viruses is represented by the mealybug Planococcus ficus<\/em> that is a key pest in South Africa, Mediterranean regions, Argentina and some areas of California that can feed on plants roots.<\/h5>\n[caption id=\"attachment_4465\" align=\"alignleft\" width=\"300\"]
![\"\"](\"https:\/\/terrasharp.com\/wp-content\/uploads\/2018\/04\/chervec-3-300x199.jpg\")
Planococcus ficus[\/caption]\nThis means that acting only on aboveground pathogen is not enough, because some viruliferous insects can repair themselves in the soil. Also agricultural practices can spread the pathogen trough the vineyard.<\/h5>\n
There is a low but concrete risk of transmission during the pruning, when an infected plant is pruned a part of its sap (in which the viruses are present) remains on the scissors and it can be the vehicle for disease spread. No curative product exists, so prevention is the only way to reduce the impact of these viruses on agriculture.<\/h5>\n
All this information are useful because they underline that prevention is the only way to contrast this pathogen. Aerial images taken by UAVs are perfect to detect infected plant and to organize a strategy to reduce pathogen incidence. With drones, every plant is controlled, so that vine growers can act locally to improve the health of their vineyard and, as a consequence, of their wine.<\/h5>","_et_gb_content_width":"","footnotes":""},"categories":[144,146,147,145],"tags":[150,151,155,153],"class_list":["post-4464","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-disease","category-grapevine","category-leafroll","category-pests","tag-leafroll","tag-pests","tag-uav","tag-vineyards"],"_links":{"self":[{"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/posts\/4464\/"}],"collection":[{"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/posts\/"}],"about":[{"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/types\/post\/"}],"author":[{"embeddable":true,"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/users\/4\/"}],"replies":[{"embeddable":true,"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/comments\/?post=4464"}],"version-history":[{"count":9,"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/posts\/4464\/revisions\/"}],"predecessor-version":[{"id":5883,"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/posts\/4464\/revisions\/5883\/"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/media\/4473\/"}],"wp:attachment":[{"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/media\/?parent=4464"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/categories\/?post=4464"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/terrasharp.com\/en\/wp-json\/wp\/v2\/tags\/?post=4464"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}