The host of this disease is hemp (Cannabis sativa). The disease has been observed in Europe and parts of Asia, and on wild hemp in Illinois, suggesting that it has spread to the Western hemisphere.[1] The symptoms that correspond with this disease include discoloration of the leaves, irregular leaf shape and death of the leaves. The leaves will begin to turn yellow, and eventually the entire plant can die. A way to diagnose this disease is to look at the underside of the leaves. The fungus grows through the top side of the leaf and makes its fruiting body on the underside. The fruiting body is where sporangia are produced, and from the sporangia, zoospores are released, which are the infectious stage of this disease cycle.[2]
Environmentedit
Downy mildew of hemp requires cool, moist weather in order to produce spores. Usually these are the temperatures either during early spring or late fall, when it is typically cooler than 65 °F, and when the humidity is near 100%.[3] The spores are produced by the sporangia, which emerge on the underside of the leaves of the infected plant. The sporangia pop open to release the zoospores, which require water in order to swim and infect a plant. The spores can also be transported by the wind, rain, insects, and even by people. At the end of the growing season, the pathogen overwinters by oospores that can be found in the soil or on plant debris.[4]
Managementedit
There are many ways to help manage and control this disease. One of the biggest things that people can do is being consistent with cleaning their gardening supplies. However, this means cleaning your tools after tending to each plant. Also, simple practices such as a shoe washing station at the entrance of every greenhouse can help minimize the risk of spreading the disease to multiple growing areas. Crop rotation is also a beneficial cultural practice that can be done in order to reduce the spread of this disease.[5] Proper spacing between plants is also important. When the plants are very close together, they trap moisture under their canopies and can be in contact with each other. If you can prevent the plants from touching each other, you can help cut down on the spread of Pseudoperonospora.[4]If the disease has become aggressive, it may be in the grower's best option to spray for the downy mildew. Products such as copper fungicide can be effective. However, it is important to ensure that the undersides of the leaves are sprayed well with the fungicide.[2] The underside is where the fruiting bodies that produce the infectious spores are located, and this is the part of the disease cycle that you would want to target and control. As an extra precautionary measure, a grower can choose to have their soil either heat-sterilized or pasteurized. This process heats the soil to very high temperatures, with intentions to destroy the overwintering oospores which would otherwise restart the disease cycle in the spring. This practice of soil sterilization can be very costly, and may not complete eradicate all of the resting spores. However, if the problem is extreme enough, it may be one of the last options left, asides from finding a new plot of land.
Referencesedit
^McPartland, John M.; Cubeta, Marc A. (1997-07-01). "New species, combinations, host associations and location records of fungi associated with hemp (Cannabis sativa)". Mycological Research. 101 (7): 853–857. doi:10.1017/S0953756297003584. ISSN 0953-7562.
^Hermann, Anndrea Marie (2008). "The effect of plant population density and harvest timing on agronomic fibre yield and quality characteristics of industrial hemp (Cannabis), cultivar Alyssa, grown in the Parkland region of Manitoba, Canada". {{cite journal}}: Cite journal requires |journal= (help)
April 15, 2024
pseudoperonospora, cannabina, plant, pathogen, that, causes, downy, mildew, which, fungal, like, disease, caused, oomycete, scientific, classificationdomain, eukaryotaclade, diaphoretickesclade, sarclade, stramenopilesphylum, oomycotaorder, peronosporalesfamil. Pseudoperonospora cannabina is a plant pathogen that causes downy mildew which is a fungal like disease caused by an oomycete Pseudoperonospora cannabinaScientific classificationDomain EukaryotaClade DiaphoretickesClade SARClade StramenopilesPhylum OomycotaOrder PeronosporalesFamily PeronosporaceaeGenus PseudoperonosporaSpecies P cannabinaBinomial namePseudoperonospora cannabina G H Otth Curzi 1926 SynonymsPeronoplasmopara cannabina G H Otth PeglionPeronospora cannabina G H Otth 1869 Contents 1 Host and symptoms 2 Environment 3 Management 4 ReferencesHost and symptoms editThe host of this disease is hemp Cannabis sativa The disease has been observed in Europe and parts of Asia and on wild hemp in Illinois suggesting that it has spread to the Western hemisphere 1 The symptoms that correspond with this disease include discoloration of the leaves irregular leaf shape and death of the leaves The leaves will begin to turn yellow and eventually the entire plant can die A way to diagnose this disease is to look at the underside of the leaves The fungus grows through the top side of the leaf and makes its fruiting body on the underside The fruiting body is where sporangia are produced and from the sporangia zoospores are released which are the infectious stage of this disease cycle 2 Environment editDowny mildew of hemp requires cool moist weather in order to produce spores Usually these are the temperatures either during early spring or late fall when it is typically cooler than 65 F and when the humidity is near 100 3 The spores are produced by the sporangia which emerge on the underside of the leaves of the infected plant The sporangia pop open to release the zoospores which require water in order to swim and infect a plant The spores can also be transported by the wind rain insects and even by people At the end of the growing season the pathogen overwinters by oospores that can be found in the soil or on plant debris 4 Management editThere are many ways to help manage and control this disease One of the biggest things that people can do is being consistent with cleaning their gardening supplies However this means cleaning your tools after tending to each plant Also simple practices such as a shoe washing station at the entrance of every greenhouse can help minimize the risk of spreading the disease to multiple growing areas Crop rotation is also a beneficial cultural practice that can be done in order to reduce the spread of this disease 5 Proper spacing between plants is also important When the plants are very close together they trap moisture under their canopies and can be in contact with each other If you can prevent the plants from touching each other you can help cut down on the spread of Pseudoperonospora 4 If the disease has become aggressive it may be in the grower s best option to spray for the downy mildew Products such as copper fungicide can be effective However it is important to ensure that the undersides of the leaves are sprayed well with the fungicide 2 The underside is where the fruiting bodies that produce the infectious spores are located and this is the part of the disease cycle that you would want to target and control As an extra precautionary measure a grower can choose to have their soil either heat sterilized or pasteurized This process heats the soil to very high temperatures with intentions to destroy the overwintering oospores which would otherwise restart the disease cycle in the spring This practice of soil sterilization can be very costly and may not complete eradicate all of the resting spores However if the problem is extreme enough it may be one of the last options left asides from finding a new plot of land References edit McPartland John M Cubeta Marc A 1997 07 01 New species combinations host associations and location records of fungi associated with hemp Cannabis sativa Mycological Research 101 7 853 857 doi 10 1017 S0953756297003584 ISSN 0953 7562 a b downy mildew of hemp Pseudoperonospora cannabina Technical Factsheet Plantwise Knowledge Bank Retrieved 2018 12 31 Downy Mildew Symptoms Treatment and Control Planet Natural Retrieved 2018 12 31 a b Beckerman Janna April 2009 Diseases of Landscape Plants Downy Mildew PDF Purdue Extension Retrieved 2018 12 31 Hermann Anndrea Marie 2008 The effect of plant population density and harvest timing on agronomic fibre yield and quality characteristics of industrial hemp Cannabis cultivar Alyssa grown in the Parkland region of Manitoba Canada a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help Retrieved from https en wikipedia org w index php title Pseudoperonospora cannabina amp oldid 1218928794, wikipedia, wiki, book, books, library,
