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Diseases of hemp caused by fungi and oomycetes worldwide and in Poland, listed in the scientific literature
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Hemp (Cannabis sativa L.) is a treasure trove plant for both sustainable agriculture and industrial usage. It has multi-application properties due to the production of fibre and high quality oil, biomass as a safe source of energy, and numerous compounds for the pharmaceutical sectors, including mainly cannabinoids (THC and CBD) which have a wide r...
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... researchers use synoptic keys which rely on recognition patterns, while others prefer dichotomous keys with the structure of decision trees (McPartland, 2000). Table 1 shows the diseases occurring on hemp, caused by fungi and oomycetes. The list is based on the description of McPartland (2000) and Polish literature on this topic (Pietkiewicz, 1958;Czyzewska & Zarzycka, 1961;Zarzycka & Jaranowska, 1977) and our personal observations (unpublished). ...
Citations
... Leaf diseases caused by fungi in cannabis include yellow leaf spot disease caused by Septoria cannabis and S. neocannabina, brown leaf spot caused by Phoma and Ascochyta species, white leaf spot caused by Diaporthe ganjae (=Phomopsis ganjae) [15], olive leaf spot caused by Pseudocercospora cannabina and Cercospora cannabis, Stemphylium Leaf and Stem Spot caused by Stemphylium botryosum and S. herbarum, black mildew caused by Schiffnerula cannabis, Black Dot caused by Epicoccum nigrum, and Pepper spot caused by Leptosphaerulina trifolii [16]. Among them, leaf spot disease caused by Pseudocercospora cannabina remains a high-priority disease [17]. ...
Cannabis sativa is gaining attention as an agronomically important crop in many countries around the world. The identification and control of leaf diseases in cannabis are very important for cannabis cultivators as leaves are the most economically important part of the cannabis plants. In 2022, several cannabis plants in cultivations showing olive leaf spot symptoms emerged from Chiang Rai province, Thailand. Preliminary studies indicated that the causal organism is Pseudocercospora sp. Species of Pseudocercospora are important plant pathogens that are now identified through morphological studies combined with DNA sequence data of Internal Transcribed Spacer (ITS), Actin (act), Translation Elongation Factor (tef), and RNA Polymerase II second largest subunit (rpb2) gene regions. We aimed to investigate and understand the emergence of olive leaf spot disease in cannabis plants in Chiang Rai province, Thailand, with a specific focus on the combined morpho-molecular identification of the pathogen. In our study, Pseudocercospora cannabina, the causal organism of olive leaf spot disease, was identified as the leaf spot-causing pathogen with both morphological and phylogenetic analyses. Our study is the first to provide molecular data for Ps. cannabina as the typenor Ps. cannabina isolates from previous studies have made molecular data available for this species. A pathogenicity test, re-isolation, and identification steps were performed to fulfill Koch’s postulates. This comprehensive approach enhances our understanding of the olive leaf spot disease and its causative agent in cannabis.
... With the changing legislation of cannabis around the world, the study focused on the potential improvement of the industrial hemp and marijuana growth (Cherney and Small, 2016). The use of pesticides or fungicides on marijuana can affect bud quality by changing the taste, aroma and product quality (Bakro et al., 2018). It can increase the potential of human and environmental exposure to chemicals. ...
... Agriculturally, industrial hemp is a relatively high-yielding crop, with low or no pesticide requirement, and modest demands for fertilizer (Campiglia et al. 2017). However, relatively little is known about the pests and diseases that are associated with this crop (Bakro et al. 2018). In a preliminary study that was carried out at the Institute of Plant Breeding and Genomic Resources (IPGRB) (Thermi, Greece), the occurrence of a total of three different insect classes were observed, with the most numerous being the Hemiptera, mainly herbivores. ...
The brown marmorated stink bug (BMSB), Halyomorpha halys (Hemiptera: Pentatomidae), is a highly polyphagous pest that causes severe damage to a wide range of hosts by feeding on vegetative and reproductive organs of plants, as well as on seeds. The aim of the present study was to determine if BMSB injures hemp seeds and to what the extent of this injury was, in terms of seed weight and quality. At the growth stage of the formation of female inflorescence, a BMSB individual was inserted into separate sleeve cages that were placed on the top of female industrial hemp plants. The entire procedure was repeated at two more growth stages, 20 and 40 days after the formation of the female inflorescence. According to our results, no differences were observed among infested and non-infested plants regarding seed weight and percentage of empty seeds. Conversely, infested plants displayed significantly lower mean protein content 20 days after the formation of the female inflorescence. Likewise, infested plants exhibited the lowest mean oil content 20 days after the formation of the female inflorescence.
... Hemp grown for grain and fiber is normally direct-seeded in the field, whereas cannabinoid hemp is often grown in a greenhouse or transplanted to the field [6]. Several recent publications reported numerous pest and disease problems associated with the production of hemp [7][8][9]. Damping-off, along with powdery mildew, Botrytis grey mold, and multiple leaf spot diseases, were all cited as impediments to commercial hemp production [9][10][11][12][13]. In addition, seedlings started in the greenhouse often have poor root development that leads to increased susceptibility to pathogens and biotic stresses when transplanted into the field. ...
... Several recent publications reported numerous pest and disease problems associated with the production of hemp [7][8][9]. Damping-off, along with powdery mildew, Botrytis grey mold, and multiple leaf spot diseases, were all cited as impediments to commercial hemp production [9][10][11][12][13]. In addition, seedlings started in the greenhouse often have poor root development that leads to increased susceptibility to pathogens and biotic stresses when transplanted into the field. ...
The purpose of this research was to collect efficacy data on biological, biochemical, and chemical fungicide seed treatments on hemp (Cannabis sativa L.) to mitigate damping-off and enhance field stand establishment. Seed treatments were evaluated in fields in New York (NY), North Dakota (ND), and Virginia (VA) and at two planting dates in each state in 2020. A single seed lot of a dual-purpose (fiber + grain) cultivar (‘Anka’) was treated using a laboratory-scale rotary pan coater. Five biological, two biochemical, and four chemical seed treatments were tested. A laboratory germination test revealed that seed treatments did not exhibit phytotoxicity when compared to the non-treated control. A laboratory bioassay with naturally infested soil was used to assess the preliminary activity of seed treatments for protection against damping-off. The biochemical seed treatment Ultim® (active ingredient; organic copper) performed as well as the chemical treatments Apron XL® + Maxim® 4FS and Mertect® 340F in preventing damping-off whereas the biological treatments did not differ from the non-treated control in terms of disease incidence. In all field tests, biological seed treatments did not improve plant stands compared to the non-treated control. Biochemical seed treatments Prudent 44® with Nutrol® (active ingredient; phosphite) and Ultim®, along with chemical seed treatments, had acceptable efficacy and improved stand establishment compared to the non-treated control across field locations. Based on efficacy results from laboratory and field trials, the copper seed treatment has potential for both conventional and organic hemp production.
... While most hemp and marijuana diseases are caused by fungi and oomycetes, and occasionally by a few bacteria and viruses, other common biotic aggressors include insects, mites, nematodes, weeds, and parasitic plants (McPartland et al., 2000). The prevalence of each disease and pest varies between indoor and outdoor cropping systems (Punja, 2021), but also between fiber, oilseed, and drug-type crops (Bakro et al., 2018;Thiessen et al., 2020). ...
... In hemp outdoor production, dense direct-seeded plant stands tend to promote soilborne damping-off pathogens such as Pythium, Thielaviopsis, Fusarium, and Rhizoctonia (Thiessen et al., 2020), while various stem-infecting pathogens, including Fusarium, Sclerotinia, Phoma, and Verticillium, further reduce oilseed and fiber yields by wilting tissues and collapsing mature plants (McPartland et al., 2000;Bakro et al., 2018). Common outdoor pests include lepidopterous stem borers, beetles, root grubs, caterpillars, leaf miners, seed-eating birds and weeds (McPartland, 1996b). ...
Among the oldest domesticated crops, cannabis plants ( Cannabis sativa L., marijuana and hemp) have been used to produce food, fiber, and drugs for thousands of years. With the ongoing legalization of cannabis in several jurisdictions worldwide, a new high-value market is emerging for the supply of marijuana and hemp products. This creates unprecedented challenges to achieve better yields and environmental sustainability, while lowering production costs. In this review, we discuss the opportunities and challenges pertaining to the use of beneficial Pseudomonas spp. bacteria as crop inoculants to improve productivity. The prevalence and diversity of naturally occurring Pseudomonas strains within the cannabis microbiome is overviewed, followed by their potential mechanisms involved in plant growth promotion and tolerance to abiotic and biotic stresses. Emphasis is placed on specific aspects relevant for hemp and marijuana crops in various production systems. Finally, factors likely to influence inoculant efficacy are provided, along with strategies to identify promising strains, overcome commercialization bottlenecks, and design adapted formulations. This work aims at supporting the development of the cannabis industry in a sustainable way, by exploiting the many beneficial attributes of Pseudomonas spp.
... Pests that feed on aerial parts cause the greatest damage. In recent years, European corn borer, Ostrinia nubilalis Hbn., silver Y moth, Autographa gamma (L.) and European hop flea beetle, Psylliodes attenuata (Koch), have been responsible for significant damage to hemp grown in Europe [42]. Potential damage of flower buds and seeds is possible from Eurasian hemp borer, Grapholita delineana Walker. ...
The hemp aphid Phorodon cannabis Passerini is a well- known (Asia, Europe) or newly emerging (North America) insect. It is a monophagous insect pest causing considerable damage in field and glasshouse cultivations. The aim of this work was to study the effects of meteorological (temperature) and agronomical (herbicide) factors on the biology of the hemp aphid. In one experiment, hemp plants were kept at constant temperatures ranging from 20 to 30 °C, and aphid survival and fecundity were measured. In a related experiment conducted at 20 °C, plants were treated with field-appropriate rates of a selective graminicide containing quizalofop-P-tefuryl (40 gL−1, 4.38%, HRAC group 1), commonly used to control weeds in hemp, and aphid enzyme activity was measured in addition to population parameters. We found that hemp aphids could live, feed and reproduce within the whole studied range of temperatures, demonstrating its great evolutionary plasticity. However, the optimal temperature for development was 25 °C, at which the insect lived and reproduced for 25 and 15 days, respectively, with an average fecundity of 7.5 nymphs per reproduction day. The herbicide treatment increased the activity of superoxide dismutase (SOD), catalase (CAT), β-glucosidase, S-glutathione transferase (GST), oxidoreductive peroxidase (POD), and polyphenol oxidase (PPO) in the aphids, but only on certain days after treatment, which indicates a mild stress in aphid tissues, related to a higher reproduction and changed feeding behavior; aphids moved from the actively growing tips compared to untreated plants. The results of these experiments are discussed in terms of the impact on the future management of this pest.
... Ó çâ'ÿçêó ç³ ñòð³ìêèìè çì³íàìè êë³ìàòó, ãëîáàëüíèì ï³äâèùåííÿì ð³âíÿ òåìïåðàòóðè [5,6], ïîðóøåííÿì ñ³âîçì³í, ñïðîùåííÿì òåõíîëîã³é âèðîùóâàííÿ òà ïîñëàáëåííÿì ðîáîòè ùîäî ñòâîðåííÿ êîìïëåêñíî ñò³éêèõ ñîðò³â îñòàíí³ìè ðîêàìè ïîã³ðøóºòüñÿ ô³òîñàí³òàðíèé ñòàí ïîñ³â³â êîíîïåëü ïîñ³âíèõ, ùî ñïðèÿº íàêîïè÷åííþ øê³äëèâèõ âèä³â êîìàõ. Çíà÷íîþ ì³ðîþ òàêîìó ñòàíó ðå÷åé â Óêðà¿í³ â îñòàíí³ äåñÿòèð³÷÷ÿ ñïðèÿº ñòð³ìêå çðîñòàííÿ ïëîù ïîñ³âó òîâñòîñòåáëîâèõ ïðîñàïíèõ êóëüòóð (êóêóðóäçà, ñîíÿøíèê), ÿê³ ìàþòü ñï³ëüíèõ ç êîíîïëÿìè êîìàõ-øê³äíèê³â [7,8]. ...
... Ïåð-ø³ çãàäêè ïðî ¿õ âèðîùóâàííÿ ñïî÷àòêó, ÿê ë³êàðñüêî¿, à ï³çí³øå, ÿê ïðÿäèâíî¿ ðîñëèíè ìîaeíà çíàéòè ó êèòàéñüêîìó ìàíó-ñêðèïò³, ÿêèé äàòîâàíèé ðîêàìè äî íàøî¿ åðè [10][11][12] . Âîäíî÷àñ, íà êîíîïëÿõ ïîñ³âíèõ òèñÿ÷î-ë³òòÿìè ôîðìóâàâñÿ øê³äëèâèé åíòîìîêîìïëåêñ, ÿêèé çàëåaeíî â³ä êîíêðåòíèõ óìîâ ñåðåäîâèùà ïîñòóïîâî äîïîâíþâàâñÿ ³íòðîäóêîâàíèìè, àäàïòîâàíèìè âèäàìè êîìàõ, ³ íà ðàç³ º äîñèòü ÷èñëåííèì [7,8,[13][14][15][16][17][18]. Ã.Â. ...
... ¯õí³ ëè÷èíêè ðîáëÿòü ó òêàíèíàõ ëèñòê³â, ð³äøå ñòåáåë, âóçüê³ çèãçàãîïîä³áí³ õîäè, òàê çâàí³ «ì³íè» (ðèñ. 6 á), ùî º íàñë³äêîì çìåíøåííÿ àñèì³ëþþ-÷î¿ çäàòíîñò³ ëèñòê³â òà ïîðóøåííÿ ïðîöåñ³â òðàíñï³ðàö³¿ ðîñëèí êîíîïåëü [7,8,15,16,18]. ...
Goal. To study the genesis of the harmful hemp entomofauna, to analyze the areas of expansion, features of development and harmfulness of a complex of insect phytophages. Methods. Information-analytical. Collection and research of information data of Internet resources and available specialized literature. Results. Hemp plants are damaged by a large number of both polyphage and specialized insect phytophages. With a high level of adaptability and ecological plasticity, they are capable of causing significant damage to hemp crops and sometimes even completely destroying their seedlings. Among the polyphage insects, pests from the families are of particular danger: (Elateridae), (Scarabaeidae), (Curculionidae), (Cerambycidae), (Mordellidae), (Noctuidae), (Pyralidae), (Erebidae), (Nymphalidae), (Lycaenidae), (Agromyzidae), (Orthoptera), (Acrididae), (Tettigoniidae), (Aphidiidae), (Miridae) and (Pentatomidae). The dominant specialized phytophages in the hemp field are: flea beetle — Psylliodes attenuata Koch. (Coleoptera, Chrysomelidae), tumbling flower beetles — Mordellistena micans (Coleoptera, Mordellidae), hemp moth — Grapholitha delineana Walk (Lepidoptera, Tortricidae); hemp aphids — Phorodon cannabis Pass (Homoptera, Aphidiidae). Conclusions. The genesis of the harmful hemp field entomofauna has been studied. It has been established that, for thousand years, a harmful entomocomplex has been forming on hemp, which, depending on the specific environmental conditions, has been gradually supplemented by introduced, adapted insect species, and at present it is quite numerous. Thus, according to various data, the total entomocomplex of hemp includes 240—300 species and has more than 70 specialized and polyphage insect phytophages, which can cause significant damage to the sprouting seeds, root system, overground vegetative and reproductive part of the plant.
The paper analyzes the influence of protective measures, seed dressing and ground processing of non-narcotic hemp fields on the morphometric parameters of plants, damage by pests and diseases, and crop yield. The article focuses on the effect of dressing agents in various combinations on the growth processes of cannabis seeds in the early stages of development. In tests, laboratory and field, seed treatments with Benorade and Celeste Top played the greatest stimulating role. The best results in reducing plant damage by Psylloides attenuate (Koch) 66.7 and 60.0% with a duration of protection of up to four to five pairs of leaves were obtained with the use of Tabu + Albit preparations for seed treatment and Samurai Super insecticide for ground application. With the help of Celeste Top in combination with the studied fungicides, root rot was suppressed, while the prevalence of the disease was reduced by 24.4 and 24.8% compared with the absolute control. A high increase in the yield of stems was guaranteed by the treatment of plants with an insecticide and seeds with Celest Top preparations in combination with Albit and Benorad 2.19 and 2.10 t/ha. A significant increase in seed yield was recorded in the variants when seeds were disinfected with the developed compositions Bunker + Celeste Top, Taboo and Benorade + Celeste Top 0.29 and 0.24 t/ha with the involvement of an insecticide during ground cultivation of the crop.
Determining the risks associated with a high degree of damage to new varieties of hemp is relevant to ensure effective control of phytophages at all stages of cultivation. The aim of the research is to study the biological resistance of new varieties of hemp to the main phytophagous insects in the north-eastern forest-steppe zone of Ukraine. The research was conducted in 2019‒2020 on the natural background of hemp plant population by pests according to generally accepted entomology methods in the field of the scientific and experimental base of the Institute of Agriculture of the North-east of the National Academy of Agrarian Sciences of Ukraine, located in the northeastern Forest-Steppe of Ukraine. The material for the research was new hemp varieties of Ukrainian selection, namely Hlesiia, Hloba, Lara and Sula, which were compared with the standard variety Hliana. Weather conditions in the years of research has significant difference between themselves. Thus, the vegetation period of 2019 was characterized by an extreme deficit of precipitation against the background of higher temperatures, which contributed to the formation of high population density of major pests in the study areas and significant damage to hemp plants throughout the growing season. 2020 was marked by higher temperatures with moderate humidity. Heavy rainfall, which exceeded the average long-term norm by 1.7 times and the average daily temperature was 2.0 °C lower in May, restrained the going out of phytophagous insects from wintering grounds, which reflected in less damage to feed plants in the initial stages of organogenesis. It was found that in the conditions of the north-eastern Forest-Steppe of Ukraine during 2019‒2020 the main species of pests in the hemp field were: hemp flea beetle (Psylliodes attenuatа Koch, 1803) – 71.5 % of the total of phytophages in the herbage, sunflower tumbling-flower beetle (Mordellistena parvula Gyllenhal, 1827) – 3.20 %, beet leaf aphid (Aphis fabae Scopoli, 1763) – 0.75 % and еuropean corn borer (Ostrinia nubilalis Hübner, 1796) – 0.06 %. It was investigated that the varietal characteristics of hemp plant affect the level of damage by dominant phytophagous insects. Thus, the plants of the Hloba variety had a significantly lower level of damage by the hemp flea beetle P. attenuata (Koch, 1803) and were distinguished by a high level of resistance to other main phytophages. The greatest damage and population of hemp plants by dominant phytophages was noted for late-ripening variety ‒ Lara and somewhat less for Sula variety. The obtained research results will be used in the development of a modern environmentally-oriented system of hemp protection, as well as in the search for mechanisms of resistance to insect pests in the further breeding process.
The agrobiocenosis of the grass stand of hemp field is a specific plant biotope, which is a place of shelter, feeding, resettlement, and breeding for many insect populations, which in one way or another affecting the growth, development and yield of hemp plsnts. Taking this into consideration awareness of the species composition of phytophagous insects as well as the complex of their natural enemies and neutral species became especially relevant awareness due to the necessary to develop an effective system of protection of hemp in the context of current conditions. The aim of the research is to improve the ecologically oriented system of hemp protection by means of studying the taxonomic composition of entomofauna in the grass stand, as well as the trophic and ecological structure of insect groups associated with that habitat. The studies was conducted in 2019-2021 on the basis of the Northeast Agricultural Institute of the National Academy of Agrarian Sciences out during the vegetation of plants by means of mowing with a standard entomological net every ten days, from 10.00 till 15.00 o’clock when the insects were the most active. The current taxonomic composition of entomocomplex of the grass stand in hemp field is represented by 174 species of insects that belong to 76 families and 9 orders. The Coleoptera turned out to be the largest in terms of the species diversity and the number of individuals (56 species from 16 families and 74.6% of the number of captured insects). Were also detected insects from the orders Hymenoptera (31 species from 15 families), Hemiptera (30 species from 11 families), Diptera (20 species from 12 families), Homoptera (17 species from 8 families), Lepidoptera (12 species from 8 families), Orthoptera (4 species from 3 families), Neuroptera (3 species from 2 families), Thysanoptera (one species) were also detected. In the trophic structure of the entomofauna in grass stand of hemp field, 85.9% of the number and 59.8% of the species diversity account for phytophagous insects. Pests of hemp were 39 species of insects from 22 families, and 6 orders. Among them, 36 species, which accounted for 18.7% of the total number of specimens, were polyphagous and three, or 81.3%, were specialized species. The presence of insect pests in the grass stand of hemp field was characterized by oligodominance, as evidenced by quantitative and qualitative data, and indices of species diversity. Thus, the dominance structure is represented by one eudominant (Psylliodes attenuata – 81.1%), one subdominant (Mordellistena parvula – 4.72%), four recedents (Lygus pratensis, L. rugulipennis, Lygocoris pabulinus, Stictocephala bisonia – 8.6%) and, 33 subrecedents (5.58%). The obtained research results will be used in order to solve the problems related to the danger of basic phytophagous insects during the vegetation period of cannabis sativa plants and to develop a modern environmentally-oriented strategy to control their numbers and harmfulness
